MySQL Connector/J 5.1 Developer Guide

   Abstract

   This manual describes how to install, configure, and develop
   database applications using MySQL Connector/J, the JDBC
   driver for communicating with MySQL servers.

   For notes detailing the changes in each release of
   Connector/J, see MySQL Connector/J Release Notes
   (http://dev.mysql.com/doc/relnotes/connector-j/en/).

   For legal information, see the Legal Notices.

   For help with using MySQL, please visit either the MySQL
   Forums (http://forums.mysql.com) or MySQL Mailing Lists
   (http://lists.mysql.com), where you can discuss your issues
   with other MySQL users.

   For additional documentation on MySQL products, including
   translations of the documentation into other languages, and
   downloadable versions in variety of formats, including HTML
   and PDF formats, see the MySQL Documentation Library
   (http://dev.mysql.com/doc).

   Licensing information.  This product may include third-party
   software, used under license. If you are using a Commercial
   release of MySQL Connector/J 5.1, see this document
   (http://downloads.mysql.com/docs/licenses/connector-j-5.1-com
   -en.pdf) for licensing information, including licensing
   information relating to third-party software that may be
   included in this Commercial release. If you are using a
   Community release of MySQL Connector/J 5.1, see this document
   (http://downloads.mysql.com/docs/licenses/connector-j-5.1-gpl
   -en.pdf) for licensing information, including licensing
   information relating to third-party software that may be
   included in this Community release.

   Document generated on: 2016-03-28 (revision: 47177)
     ________________________________________________________

Preface and Legal Notices

   This manual describes how to install, configure, and develop
   database applications using MySQL Connector/J, the JDBC
   driver for communicating with MySQL servers.

Legal Notices

   Copyright (c) 1998, 2016, Oracle and/or its affiliates. All
   rights reserved.

   This software and related documentation are provided under a
   license agreement containing restrictions on use and
   disclosure and are protected by intellectual property laws.
   Except as expressly permitted in your license agreement or
   allowed by law, you may not use, copy, reproduce, translate,
   broadcast, modify, license, transmit, distribute, exhibit,
   perform, publish, or display any part, in any form, or by any
   means. Reverse engineering, disassembly, or decompilation of
   this software, unless required by law for interoperability,
   is prohibited.

   The information contained herein is subject to change without
   notice and is not warranted to be error-free. If you find any
   errors, please report them to us in writing.

   If this is software or related documentation that is
   delivered to the U.S. Government or anyone licensing it on
   behalf of the U.S. Government, then the following notice is
   applicable:

   U.S. GOVERNMENT END USERS: Oracle programs, including any
   operating system, integrated software, any programs installed
   on the hardware, and/or documentation, delivered to U.S.
   Government end users are "commercial computer software"
   pursuant to the applicable Federal Acquisition Regulation and
   agency-specific supplemental regulations. As such, use,
   duplication, disclosure, modification, and adaptation of the
   programs, including any operating system, integrated
   software, any programs installed on the hardware, and/or
   documentation, shall be subject to license terms and license
   restrictions applicable to the programs. No other rights are
   granted to the U.S. Government.

   This software or hardware is developed for general use in a
   variety of information management applications. It is not
   developed or intended for use in any inherently dangerous
   applications, including applications that may create a risk
   of personal injury. If you use this software or hardware in
   dangerous applications, then you shall be responsible to take
   all appropriate fail-safe, backup, redundancy, and other
   measures to ensure its safe use. Oracle Corporation and its
   affiliates disclaim any liability for any damages caused by
   use of this software or hardware in dangerous applications.

   Oracle and Java are registered trademarks of Oracle and/or
   its affiliates. Other names may be trademarks of their
   respective owners.

   Intel and Intel Xeon are trademarks or registered trademarks
   of Intel Corporation. All SPARC trademarks are used under
   license and are trademarks or registered trademarks of SPARC
   International, Inc. AMD, Opteron, the AMD logo, and the AMD
   Opteron logo are trademarks or registered trademarks of
   Advanced Micro Devices. UNIX is a registered trademark of The
   Open Group.

   This software or hardware and documentation may provide
   access to or information about content, products, and
   services from third parties. Oracle Corporation and its
   affiliates are not responsible for and expressly disclaim all
   warranties of any kind with respect to third-party content,
   products, and services unless otherwise set forth in an
   applicable agreement between you and Oracle. Oracle
   Corporation and its affiliates will not be responsible for
   any loss, costs, or damages incurred due to your access to or
   use of third-party content, products, or services, except as
   set forth in an applicable agreement between you and Oracle.

   Documentation Accessibility

   For information about Oracle's commitment to accessibility,
   visit the Oracle Accessibility Program website at
   http://www.oracle.com/pls/topic/lookup?ctx=acc&id=docacc.

   Access to Oracle Support

   Oracle customers that have purchased support have access to
   electronic support through My Oracle Support. For
   information, visit
   http://www.oracle.com/pls/topic/lookup?ctx=acc&id=info or
   visit http://www.oracle.com/pls/topic/lookup?ctx=acc&id=trs
   if you are hearing impaired.

   This documentation is NOT distributed under a GPL license.
   Use of this documentation is subject to the following terms:

   You may create a printed copy of this documentation solely
   for your own personal use. Conversion to other formats is
   allowed as long as the actual content is not altered or
   edited in any way. You shall not publish or distribute this
   documentation in any form or on any media, except if you
   distribute the documentation in a manner similar to how
   Oracle disseminates it (that is, electronically for download
   on a Web site with the software) or on a CD-ROM or similar
   medium, provided however that the documentation is
   disseminated together with the software on the same medium.
   Any other use, such as any dissemination of printed copies or
   use of this documentation, in whole or in part, in another
   publication, requires the prior written consent from an
   authorized representative of Oracle. Oracle and/or its
   affiliates reserve any and all rights to this documentation
   not expressly granted above.

Chapter 1 Overview of MySQL Connector/J

   MySQL provides connectivity for client applications developed
   in the Java programming language with MySQL Connector/J, a
   driver that implements the Java Database Connectivity (JDBC)
   API
   (http://www.oracle.com/technetwork/java/javase/jdbc/index.htm
   l).

   MySQL Connector/J is a JDBC Type 4 driver. Different versions
   are available that are compatible with the JDBC 3.0 and JDBC
   4.x specifications (see Chapter 2, "Connector/J Versions").
   The Type 4 designation means that the driver is a pure Java
   implementation of the MySQL protocol and does not rely on the
   MySQL client libraries.

   For large-scale programs that use common design patterns of
   data access, consider using one of the popular persistence
   frameworks such as Hibernate (http://www.hibernate.org/),
   Spring's JDBC templates (http://www.springframework.org/) or
   Ibatis SQL Maps (http://ibatis.apache.org/) to reduce the
   amount of JDBC code for you to debug, tune, secure, and
   maintain.

Key Topics


     * For help with connection strings, connection options, and
       setting up your connection through JDBC, see Section 5.1,
       "Driver/Datasource Class Names, URL Syntax and
       Configuration Properties for Connector/J."

Chapter 2 Connector/J Versions

   There are currently four versions of MySQL Connector/J
   available:

     * Connector/J 5.1 is a Type 4 pure Java JDBC driver, which
       conforms to the JDBC 3.0, 4.0, 4.1, and 4.2
       specifications. It provides compatibility with all the
       functionality of MySQL, including 4.1, 5.0, 5.1, 5.5,
       5.6, and 5.7. Connector/J 5.1 provides ease of
       development features, including auto-registration with
       the Driver Manager, standardized validity checks,
       categorized SQLExceptions, support for large update
       counts, support for local and offset date-time variants
       from the java.time package, support for JDBC-4.x XML
       processing, support for per connection client
       information, and support for the NCHAR
       (http://dev.mysql.com/doc/refman/5.7/en/char.html),
       NVARCHAR
       (http://dev.mysql.com/doc/refman/5.7/en/char.html) and
       NCLOB data types. This release also includes all bug
       fixes up to and including Connector/J 5.0.6.

     * Connector/J 5.0 provides support for all the
       functionality offered by Connector/J 3.1 and includes
       distributed transaction (XA) support.

     * Connector/J 3.1 was designed for connectivity to MySQL
       4.1 and MySQL 5.0 servers and provides support for all
       the functionality in MySQL 5.0 except distributed
       transaction (XA) support.

     * Connector/J 3.0 provides core functionality and was
       designed for connectivity to MySQL 3.x or MySQL 4.1
       servers, although it provides basic compatibility with
       later versions of MySQL. Connector/J 3.0 does not support
       server-side prepared statements, and does not support any
       of the features in versions of MySQL later than 4.1.

   The following table summarizes the Connector/J versions
   available, along with the details of JDBC driver type, what
   version of the JDBC API it supports, what versions of MySQL
   Server it works with, and whether it is currently supported
   or not:

   Table 2.1 Summary of Connector/J Versions
   Connector/J version Driver Type JDBC version MySQL Server
   version Status
   5.1 4 3.0, 4.0, 4.1, 4.2 4.1, 5.0, 5.1, 5.5, 5.6, 5.7
   Recommended version
   5.0 4 3.0 4.1, 5.0 Released version
   3.1 4 3.0 4.1, 5.0 Obsolete
   3.0 4 3.0 3.x, 4.1 Obsolete

   The current recommended version for Connector/J is 5.1. This
   guide covers all four connector versions, with specific notes
   given where a setting applies to a specific option.

2.1 Connector/J Release Notes and Change History

   For details of new features and bug fixes in each Connector/J
   release, see the MySQL Connector/J Release Notes
   (http://dev.mysql.com/doc/relnotes/connector-j/en/).

2.2 Java Versions Supported

   The following table summarizes what version of JRE is
   required to use Connector/J with Java applications, and what
   version of JDK is required to build Connector/J source code:

   Table 2.2 Summary of Java Versions Required by Connector/J
   Connector/J version JRE Supported JDK required (to build
   source code)
   5.1 1.5.x, 1.6.x, 1.7.x, 1.8.x 1.6.x and 1.5.x
   5.0 1.3.x, 1.4.x, 1.5.x, 1.6.x 1.4.2, 1.5.x, 1.6.x
   3.1 1.2.x, 1.3.x, 1.4.x, 1.5.x, 1.6.x 1.4.2, 1.5.x, 1.6.x
   3.0 1.2.x, 1.3.x, 1.4.x, 1.5.x, 1.6.x 1.4.2, 1.5.x, 1.6.x

   If you are building Connector/J from source code using the
   source distribution (see Section 3.4, "Installing from
   Source"), you must use JDK 1.4.2 or newer to compile the
   package for Connector/J 5.0 or earlier. For Connector/J 5.1,
   you must have both JDK-1.6.x AND JDK-1.5.x installed to be
   able to build the source code.

   JRE 1.7 support requires Connector/J 5.1.21 and higher.

   JRE 1.8 is required for Connector/J 5.1 to connect to MySQL
   5.6.27 and later and 5.7 with SSL/TLS when using some cipher
   suites.

   Several JDBC 4.1 methods were implemented for the first time
   in Connector/J 5.1.21.

   Because of the implementation of java.sql.Savepoint,
   Connector/J 3.1.0 and newer will not run on a Java runtime
   older than 1.4 unless the class verifier is turned off (by
   setting the -Xverify:none option to the Java runtime). This
   is because the class verifier will try to load the class
   definition for java.sql.Savepoint even though it is not
   accessed by the driver unless you actually use savepoint
   functionality.

   Caching functionality provided by Connector/J 3.1.0 or newer
   is also not available on JVMs older than 1.4.x, as it relies
   on java.util.LinkedHashMap, which was first available in
   JDK-1.4.0.

   MySQL Connector/J does not support JDK-1.1.x or JDK-1.0.x.

Chapter 3 Connector/J Installation

   You can install the Connector/J package using either the
   binary or source distribution. The binary distribution
   provides the easiest method for installation; the source
   distribution lets you customize your installation further.
   With either solution, you manually add the Connector/J
   location to your Java CLASSPATH.

   If you are upgrading from a previous version, read the
   upgrade information in Section 3.3, "Upgrading from an Older
   Version" before continuing.

   Connector/J is also available as part of the Maven project.
   For more information and to download the Connector/J JAR
   files, see the Maven repository
   (http://search.maven.org/#search|ga|1|g%3A%22mysql%22%20AND%2
   0a%3A%22mysql-connector-java%22).

3.1 Installing Connector/J from a Binary Distribution

   For the easiest method of installation, use the binary
   distribution of the Connector/J package. The binary
   distribution is available either as a tar/gzip or zip file.
   Extract it to a suitable location, then optionally make the
   information about the package available by changing your
   CLASSPATH (see Section 3.2, "Installing the Driver and
   Configuring the CLASSPATH").

   MySQL Connector/J is distributed as a .zip or .tar.gz archive
   containing the sources, the class files, and the JAR archive
   named mysql-connector-java-version-bin.jar.

   Starting with Connector/J 3.1.9, the .class files that
   constitute the JAR files are only included as part of the
   driver JAR file.

   Starting with Connector/J 3.1.8, the archive also includes a
   debug build of the driver in a file named
   mysql-connector-java-version-bin-g.jar. Do not use the debug
   build of the driver unless instructed to do so when reporting
   a problem or a bug, as it is not designed to be run in
   production environments, and will have adverse performance
   impact when used. The debug binary also depends on the
   Aspect/J runtime library, which is located in the
   src/lib/aspectjrt.jar file that comes with the Connector/J
   distribution.

   Use the appropriate graphical or command-line utility to
   extract the distribution (for example, WinZip for the .zip
   archive, and tar for the .tar.gz archive). Because there are
   potentially long file names in the distribution, we use the
   GNU tar archive format. Use GNU tar (or an application that
   understands the GNU tar archive format) to unpack the .tar.gz
   variant of the distribution.

3.2 Installing the Driver and Configuring the CLASSPATH

   Once you have extracted the distribution archive, you can
   install the driver by placing
   mysql-connector-java-version-bin.jar in your classpath,
   either by adding the full path to it to your CLASSPATH
   environment variable, or by directly specifying it with the
   command line switch -cp when starting the JVM.

   To use the driver with the JDBC DriverManager, use
   com.mysql.jdbc.Driver as the class that implements
   java.sql.Driver.

   You can set the CLASSPATH environment variable under Unix,
   Linux, or OS X either locally for a user within their
   .profile, .login or other login file. You can also set it
   globally by editing the global /etc/profile file.

   For example, add the Connector/J driver to your CLASSPATH
   using one of the following forms, depending on your command
   shell:
# Bourne-compatible shell (sh, ksh, bash, zsh):
shell> export CLASSPATH=/path/mysql-connector-java-ver-bin.jar:$CLASSP
ATH

# C shell (csh, tcsh):
shell> setenv CLASSPATH /path/mysql-connector-java-ver-bin.jar:$CLASSP
ATH

   For Windows platforms, you set the environment variable
   through the System Control Panel.

   To use MySQL Connector/J with an application server such as
   GlassFish, Tomcat, or JBoss, read your vendor's documentation
   for more information on how to configure third-party class
   libraries, as most application servers ignore the CLASSPATH
   environment variable. For configuration examples for some
   J2EE application servers, see Chapter 7, "Connection Pooling
   with Connector/J," Section 8.2, "Configuring Load Balancing
   with Connector/J," and Section 8.4, "Advanced Load-balancing
   and Failover Configuration." However, the authoritative
   source for JDBC connection pool configuration information for
   your particular application server is the documentation for
   that application server.

   If you are developing servlets or JSPs, and your application
   server is J2EE-compliant, you can put the driver's .jar file
   in the WEB-INF/lib subdirectory of your webapp, as this is a
   standard location for third party class libraries in J2EE web
   applications.

   You can also use the MysqlDataSource or
   MysqlConnectionPoolDataSource classes in the
   com.mysql.jdbc.jdbc2.optional package, if your J2EE
   application server supports or requires them. Starting with
   Connector/J 5.0.0, the javax.sql.XADataSource interface is
   implemented using the
   com.mysql.jdbc.jdbc2.optional.MysqlXADataSource class, which
   supports XA distributed transactions when used in combination
   with MySQL server version 5.0 and later.

   The various MysqlDataSource classes support the following
   parameters (through standard set mutators):

     * user

     * password

     * serverName (see the previous section about failover
       hosts)

     * databaseName

     * port

3.3 Upgrading from an Older Version

   This section has information for users who are upgrading from
   one version of Connector/J to another, or to a new version of
   the MySQL server that supports a more recent level of JDBC. A
   newer version of Connector/J might include changes to support
   new features, improve existing functionality, or comply with
   new standards.

3.3.1 Upgrading to MySQL Connector/J 5.1.x


     * In Connector/J 5.0.x and earlier, the alias for a table
       in a SELECT
       (http://dev.mysql.com/doc/refman/5.7/en/select.html)
       statement is returned when accessing the result set
       metadata using ResultSetMetaData.getColumnName(). This
       behavior however is not JDBC compliant, and in
       Connector/J 5.1, this behavior has been changed so that
       the original table name, rather than the alias, is
       returned.
       The JDBC-compliant behavior is designed to let API users
       reconstruct the DML statement based on the metadata
       within ResultSet and ResultSetMetaData.
       You can get the alias for a column in a result set by
       calling ResultSetMetaData.getColumnLabel(). To use the
       old noncompliant behavior with
       ResultSetMetaData.getColumnName(), use the
       useOldAliasMetadataBehavior option and set the value to
       true.
       In Connector/J 5.0.x, the default value of
       useOldAliasMetadataBehavior was true, but in Connector/J
       5.1 this was changed to a default value of false.

3.3.2 JDBC-Specific Issues When Upgrading to MySQL Server 4.1 or
Newer


     * Using the UTF-8 Character Encoding - Prior to MySQL
       server version 4.1, the UTF-8 character encoding was not
       supported by the server, however the JDBC driver could
       use it, allowing storage of multiple character sets in
       latin1 tables on the server.
       Starting with MySQL-4.1, this functionality is
       deprecated. If you have applications that rely on this
       functionality, and can not upgrade them to use the
       official Unicode character support in MySQL server
       version 4.1 or newer, add the following property to your
       connection URL:
       useOldUTF8Behavior=true

     * Server-side Prepared Statements - Connector/J 3.1 will
       automatically detect and use server-side prepared
       statements when they are available (MySQL server version
       4.1.0 and newer). If your application encounters issues
       with server-side prepared statements, you can revert to
       the older client-side emulated prepared statement code
       that is still presently used for MySQL servers older than
       4.1.0 with the following connection property:
       useServerPrepStmts=false

3.3.3 Upgrading from MySQL Connector/J 3.0 to 3.1

   Connector/J 3.1 is designed to be backward-compatible with
   Connector/J 3.0 as much as possible. Major changes are
   isolated to new functionality exposed in MySQL-4.1 and newer,
   which includes Unicode character sets, server-side prepared
   statements, SQLState codes returned in error messages by the
   server and various performance enhancements that can be
   enabled or disabled using configuration properties.

     * Unicode Character Sets: See the next section, as well as
       Character Set Support
       (http://dev.mysql.com/doc/refman/5.7/en/charset.html),
       for information on this MySQL feature. If you have
       something misconfigured, it will usually show up as an
       error with a message similar to Illegal mix of
       collations.

     * Server-side Prepared Statements: Connector/J 3.1 will
       automatically detect and use server-side prepared
       statements when they are available (MySQL server version
       4.1.0 and newer).
       Starting with version 3.1.7, the driver scans SQL you are
       preparing using all variants of
       Connection.prepareStatement() to determine if it is a
       supported type of statement to prepare on the server
       side, and if it is not supported by the server, it
       instead prepares it as a client-side emulated prepared
       statement. You can disable this feature by passing
       emulateUnsupportedPstmts=false in your JDBC URL.
       If your application encounters issues with server-side
       prepared statements, you can revert to the older
       client-side emulated prepared statement code that is
       still presently used for MySQL servers older than 4.1.0
       with the connection property useServerPrepStmts=false.

     * Datetimes with all-zero components (0000-00-00 ...):
       These values cannot be represented reliably in Java.
       Connector/J 3.0.x always converted them to NULL when
       being read from a ResultSet.
       Connector/J 3.1 throws an exception by default when these
       values are encountered, as this is the most correct
       behavior according to the JDBC and SQL standards. This
       behavior can be modified using the zeroDateTimeBehavior
       configuration property. The permissible values are:

          + exception (the default), which throws an
            SQLException with an SQLState of S1009.

          + convertToNull, which returns NULL instead of the
            date.

          + round, which rounds the date to the nearest closest
            value which is 0001-01-01.
       Starting with Connector/J 3.1.7, ResultSet.getString()
       can be decoupled from this behavior using
       noDatetimeStringSync=true (the default value is false) so
       that you can retrieve the unaltered all-zero value as a
       String. Note that this also precludes using any time zone
       conversions, therefore the driver will not allow you to
       enable noDatetimeStringSync and useTimezone at the same
       time.

     * New SQLState Codes: Connector/J 3.1 uses SQL:1999
       SQLState codes returned by the MySQL server (if
       supported), which are different from the legacy X/Open
       state codes that Connector/J 3.0 uses. If connected to a
       MySQL server older than MySQL-4.1.0 (the oldest version
       to return SQLStates as part of the error code), the
       driver will use a built-in mapping. You can revert to the
       old mapping by using the configuration property
       useSqlStateCodes=false.

     * ResultSet.getString(): Calling ResultSet.getString() on a
       BLOB (http://dev.mysql.com/doc/refman/5.7/en/blob.html)
       column will now return the address of the byte[] array
       that represents it, instead of a String representation of
       the BLOB
       (http://dev.mysql.com/doc/refman/5.7/en/blob.html). BLOB
       (http://dev.mysql.com/doc/refman/5.7/en/blob.html) values
       have no character set, so they cannot be converted to
       java.lang.Strings without data loss or corruption.
       To store strings in MySQL with LOB behavior, use one of
       the TEXT
       (http://dev.mysql.com/doc/refman/5.7/en/blob.html) types,
       which the driver will treat as a java.sql.Clob.

     * Debug builds: Starting with Connector/J 3.1.8 a debug
       build of the driver in a file named
       mysql-connector-java-version-bin-g.jar is shipped
       alongside the normal binary jar file that is named
       mysql-connector-java-version-bin.jar.
       Starting with Connector/J 3.1.9, we do not ship the
       .class files unbundled, they are only available in the
       JAR archives that ship with the driver.
       Do not use the debug build of the driver unless
       instructed to do so when reporting a problem or bug, as
       it is not designed to be run in production environments,
       and will have adverse performance impact when used. The
       debug binary also depends on the Aspect/J runtime
       library, which is located in the src/lib/aspectjrt.jar
       file that comes with the Connector/J distribution.

3.4 Installing from Source

   Caution

   To just get MySQL Connector/J up and running on your system,
   install Connector/J using a standard binary release
   distribution. Instructions in this section is only for users
   who, for various reasons, want to compile Connector/J from
   source.

   The requirements and steps for installing from source
   Connector/J 5.1.37 or later, 5.1.34 to 5.1.36, and 5.1.33 or
   earlier are different; check the section below that is
   relevant for the version you want.

   Installing Connector/J 5.1.37 or later from source.  To
   install MySQL Connector/J from its source tree on GitHub, you
   need to have the following software on your system:

     * A Git client, to check out the sources from our GitHub
       repository (available from http://git-scm.com/downloads).

     * Apache Ant version 1.8.2 or newer (available from
       http://ant.apache.org/).

     * JDK 1.8.x AND JDK 1.5.x.

     * JRE 1.6.x (optional)

     * JUnit libraries (available from
       https://github.com/junit-team/junit/wiki/Download-and-Ins
       tall).

     * The required .jar files from the Hibernate ORM 4.1 or 4.2
       Final release bundle, which is available at
       http://sourceforge.net/projects/hibernate/files/hibernate
       4/.

   To check out and compile MySQL Connector/J, follow these
   steps:

    1. Check out the code from the source code repository for
       MySQL Connector/J located on GitHub at
       https://github.com/mysql/mysql-connector-j; for the
       latest release of the Connector/J 5.1 series, use the
       following command:
shell> git clone https://github.com/mysql/mysql-connector-j.git

       To check out a release other than the latest one, use the
       --branch option to specify the revision tag for it:
shell> git clone --branch 5.1.xx https://github.com/mysql/mysql-connec
tor-j.git

       Under the current directory, the commands create a
       mysql-connector-j subdirectory , which contains the code
       you want.

    2. Make sure that you have both JDK 1.8.x AND JDK 1.5.x
       installed. You need both JDKs because besides supporting
       JDBC from 4.0 to 4.2, Connector/J 5.1 also supports JDBC
       3.0, which is an older version and requires the older JDK
       1.5.x.

    3. Consider also having JRE 1.6.x installed. This is
       optional: if JRE 1.6.x is not available or not supplied
       to Ant with the property com.mysql.jdbc.java6.rtjar, the
       Java 8 bootstrap classes will be used. A warning will be
       returned, saying that the bootstrap class path was not
       set with the option to compile sources written for Java
       6.

    4. Place the required junit.jar file in a separate
       directory---for example, /home/username/ant-extralibs.

    5. In the same directory for extra libraries described in
       the last step, create a directory named hibernate4, and
       put under it all the .jar files you can find under the
       /lib/required/ folder in the Hibernate ORM 4 Final
       release bundle.

    6. Change your current working directory to the
       mysql-connector-j directory created in step 1 above.

    7. In the directory, create a file named build.properties to
       indicate to Ant the locations of the root directories for
       your JDK 1.8.x and JDK 1.5.x installations, the location
       of the rt.jar of your JRE 1.6.x (optional), and the
       location of the extra libraries. The file should contain
       the following property settings, with the "path_to_*"
       parts replaced by the appropriate filepaths:
com.mysql.jdbc.jdk8=path_to_jdk_1.8
com.mysql.jdbc.jdk5=path_to_jdk_1.5
com.mysql.jdbc.java6.rtjar=path_to_rt.jar_under_jre_1.6/rt.jar
com.mysql.jdbc.extra.libs=path_to_folder_for_extra_libraries

       Alternatively, you can set the values of those properties
       through the Ant -D options.

    8. Issue the following command to compile the driver and
       create a .jar file for Connector/J:
shell> ant dist

       This creates a build directory in the current directory,
       where all the build output goes. A directory is created
       under the build directory, whose name includes the
       version number of the release you are building. That
       directory contains the sources, the compiled .class
       files, and a .jar file for deployment. For more
       information and other possible targets, including those
       that create a fully packaged distribution, issue the
       following command:
shell> ant -projecthelp


    9. Install the newly created .jar file for the JDBC driver
       as you would install a binary .jar file you download from
       MySQL by following the instructions given in Section 3.2,
       "Installing the Driver and Configuring the CLASSPATH."

   Note that a package containing both the binary and source
   code for Connector/J 5.1 can also be found at Connector/J 5.1
   Download
   (http://dev.mysql.com/downloads/connector/j/5.1.html).

   Installing Connector/J 5.1.34 to 5.1.36 from source.  To
   install MySQL Connector/J 5.1.34 to 5.1.36 from the
   Connector/J source tree on GitHub, make sure that you have
   the following software on your system:

     * A Git client, to check out the sources from our GitHub
       repository (available from http://git-scm.com/downloads).

     * Apache Ant version 1.8.2 or newer (available from
       http://ant.apache.org/).

     * JDK 1.6.x AND JDK 1.5.x.

     * JUnit libraries (available from
       https://github.com/junit-team/junit/wiki/Download-and-Ins
       tall).

     * The required .jar files from the Hibernate ORM 4.1 or 4.2
       Final release bundle, which is available at
       http://sourceforge.net/projects/hibernate/files/hibernate
       4/.

   To check out and compile MySQL Connector/J, follow these
   steps:

    1. Check out the code from the source code repository for
       MySQL Connector/J located on GitHub at
       https://github.com/mysql/mysql-connector-j, using the
       --branch option to specify the revision tag for release
       5.1.xx:
shell> git clone --branch 5.1.xx https://github.com/mysql/mysql-connec
tor-j.git

       Under the current directory, the commands create a
       mysql-connector-j subdirectory , which contains the code
       you want.

    2. Make sure that you have both JDK 1.6.x AND JDK 1.5.x
       installed. You need both JDKs because Connector/J 5.1
       supports both JDBC 3.0 (which has existed prior to JDK
       1.6.x) and JDBC 4.0.

    3. Place the required junit.jar file in a separate
       directory---for example, /home/username/ant-extralibs.

    4. In the same directory for extra libraries described in
       the last step, create a directory named hibernate4, and
       put under it all the .jar files you can find under the
       /lib/required/ folder in the Hibernate ORM 4 Final
       release bundle.

    5. Change your current working directory to the
       mysql-connector-j directory created in step 1 above.

    6. In the directory, create a file named build.properties to
       indicate to Ant the locations of the root directories for
       your JDK 1.5.x and JDK 1.6.x installations, as well as
       the location of the extra libraries. The file should
       contain the following property settings, with the
       "path_to_*" parts replaced by the appropriate filepaths:
com.mysql.jdbc.jdk5=path_to_jdk_1.5
com.mysql.jdbc.jdk6=path_to_jdk_1.6
com.mysql.jdbc.extra.libs=path_to_folder_for_extra_libraries

       Alternatively, you can set the values of those properties
       through the Ant -D options.

    7. Issue the following command to compile the driver and
       create a .jar file for Connector/J:
shell> ant dist

       This creates a build directory in the current directory,
       where all the build output goes. A directory is created
       under the build directory, whose name includes the
       version number of the release you are building. That
       directory contains the sources, the compiled .class
       files, and a .jar file for deployment. For more
       information and other possible targets, including those
       that create a fully packaged distribution, issue the
       following command:
shell> ant -projecthelp


    8. Install the newly created .jar file for the JDBC driver
       as you would install a binary .jar file you download from
       MySQL by following the instructions given in Section 3.2,
       "Installing the Driver and Configuring the CLASSPATH."

   Installing Connector/J 5.1.33 or earlier from the source
   tree.  To install MySQL Connector/J 5.1.33 or earlier from
   the Connector/J source tree on GitHub, make sure that you
   have the following software on your system:

     * A Git client, to check out the source code from our
       GitHub repository (available from
       http://git-scm.com/downloads).

     * Apache Ant version 1.7 or newer (available from
       http://ant.apache.org/).

     * JDK 1.6.x AND JDK 1.5.x. Refer to Section 2.2, "Java
       Versions Supported" for the version of Java you need to
       build or run any Connector/J release.

     * The Ant Contrib (version 1.03b is available from
       http://sourceforge.net/projects/ant-contrib/files/ant-con
       trib/1.0b3/) and JUnit (available from
       https://github.com/junit-team/junit/wiki/Download-and-Ins
       tall) libraries.


     * The required .jar files from the Hibernate ORM 4.1 or 4.2
       Final release bundle, which is available at
       http://sourceforge.net/projects/hibernate/files/hibernate
       4/.

   To check out and compile a specific branch of MySQL
   Connector/J, follow these steps:

    1. Check out the code from the source code repository for
       MySQL Connector/J located on GitHub at
       https://github.com/mysql/mysql-connector-j, using the
       --branch option to specify the revision tag for release
       5.1.xx:
shell> git clone --branch 5.1.xx https://github.com/mysql/mysql-connec
tor-j.git

       Under the current directory, the commands create a
       mysql-connector-j subdirectory , which contains the code
       you want.

    2. To build Connector/J 5.1, make sure that you have both
       JDK 1.6.x AND JDK 1.5.x installed. You need both JDKs
       because Connector/J 5.1 supports both JDBC 3.0 (which has
       existed prior to JDK 1.6.x) and JDBC 4.0. Set your
       JAVA_HOME environment variable to the path to the JDK
       1.5.x installation.

    3. Place the required ant-contrib.jar file (in exactly that
       name, without the version number in it; rename the jar
       file if needed) and junit.jar file in a separate
       directory---for example, /home/username/ant-extralibs.

    4. In the same directory for extra libraries described in
       the last step, create a directory named hibernate4, and
       put under it all the .jar files you can find under the
       /lib/required/ folder in the Hibernate ORM 4 Final
       release bundle.

    5. Change your current working directory to the
       mysql-connector-j directory created in step 1 above.

    6. In the directory, create a file named build.properties to
       indicate to Ant the locations of the Javac and rt.jar of
       your JDK 1.6.x, as well as the location of the extra
       libraries. The file should contain the following property
       settings, with the "path_to_*" parts replaced by the
       appropriate filepaths:
com.mysql.jdbc.java6.javac=path_to_javac_1.6/javac
com.mysql.jdbc.java6.rtjar=path_to_rt.jar_under_jdk_1.6/rt.jar
com.mysql.jdbc.extra.libs=path_to_folder_for_extra_libraries

       Alternatively, you can set the values of those properties
       through the Ant -D options.

    7. Issue the following command to compile the driver and
       create a .jar file for Connector/J:
shell> ant dist

       This creates a build directory in the current directory,
       where all the build output goes. A directory is created
       under the build directory, whose name includes the
       version number of the release you are building. That
       directory contains the sources, the compiled .class
       files, and a .jar file for deployment. For more
       information and other possible targets, including those
       that create a fully packaged distribution, issue the
       following command:
shell> ant -projecthelp


    8. Install the newly created .jar file for the JDBC driver
       as you would install a binary .jar file you download from
       MySQL by following the instructions given in Section 3.2,
       "Installing the Driver and Configuring the CLASSPATH."

3.5 Testing Connector/J

   The Connector/J source code repository or packages that are
   shipped with source code include an extensive test suite,
   containing test cases that can be executed independently. The
   test cases are divided into the following categories:

     * Functional or unit tests: Classes from the package
       testsuite.simple. Include test code for the main features
       of the Connector/J.

     * Performance tests: Classes from the package
       testsuite.perf. Include test code to make measurements
       for the performance of Connector/J.

     * Fabric tests: Classes from the package testsuite.fabric.
       Includes the code to test Fabric-specific features. These
       tests require the setting of some special properties that
       are not documented here. Consult the code or the
       Fabric-related targets in the bundled Ant build file,
       build.xml.

     * Regression tests: Classes from the package
       testsuite.regression. Includes code for testing bug and
       regression fixes.

   The bundled Ant build file contains targets like test and
   test-multijvm, which can facilitate the process of running
   the Connector/J tests; see the target descriptions in the
   build file for details. Besides the requirements for building
   Connector/J from the source code described in Section 3.4,
   "Installing from Source," a number of the tests also require
   the File System Service Provider 1.2 for the Java Naming and
   Directory Interface (JNDI), available at
   http://www.oracle.com/technetwork/java/javasebusiness/downloa
   ds/java-archive-downloads-java-plat-419418.html)---place the
   jar files downloaded from there into the lib directory or in
   the directory pointed to by the property
   com.mysql.jdbc.extra.libs.

   To run the test using Ant, in addition to the properties
   required for Section 3.4, "Installing from Source," you must
   set the following properties in the build.properties file or
   through the Ant -D options:

     * com.mysql.jdbc.testsuite.url: it specifies the JDBC URL
       for connection to a MySQL test server; see Section 5.1,
       "Driver/Datasource Class Names, URL Syntax and
       Configuration Properties for Connector/J."

     * com.mysql.jdbc.testsuite.jvm: the JVM to be used for the
       tests. If the property is set, the specified JVM will be
       used for all test cases except if it points to a Java 5
       directory, in which case any test cases for JDBC 4.0 and
       later are run with the JVM supplied with the property
       com.mysql.jdbc.jdk8 (for 5.1.36 and earlier, supplied
       with the property com.mysql.jdbc.jdk6). If the property
       is not set, the JVM supplied with com.mysql.jdbc.jdk5
       will be used to run test cases for JDBC 3.0 and the one
       supplied with com.mysql.jdbc.jdk8 (for 5.1.36 and
       earlier, supplied with the property com.mysql.jdbc.jdk6)
       will be used to run test cases for JDBC 4.0 and later.

   After setting these parameters, run the tests with Ant in the
   following ways:

     * Building the test target with ant test runs all test
       cases by default on a single server instance. If you want
       to run a particular test case, put the test's fully
       qualified class names in the test variable; for example:
shell > ant -Dtest=testsuite.simple.StringUtilsTest test
       You can also run individual tests in a test case by
       specifying the names of the corresponding methods in the
       methods variable, separating multiple methods by commas;
       for example:
shell > ant -Dtest=testsuite.simple.StringUtilsTest -Dmethods=testInde
xOfIgnoreCase,testGetBytes test


     * Building the test-multijvm target with ant test-multijvm
       runs all the test cases using multiple JVMs of different
       versions on multiple server instances. For example, if
       you want to run the tests using a Java 7 and a Java 8 JVM
       on three server instances with different configurations,
       you will need to use the following properties:
com.mysql.jdbc.testsuite.jvm.1=path_to_Java_7
com.mysql.jdbc.testsuite.jvm.2=path_to_Java_8
com.mysql.jdbc.testsuite.url.1=URL_to_1st_server
com.mysql.jdbc.testsuite.url.2=URL_to_2nd_server
com.mysql.jdbc.testsuite.url.3=URL_to_3rd_server
       Unlike the target test, the target test-multijvm only
       recognizes the properties com.mysql.jdbc.testsuite.jvm.N
       and com.mysql.jdbc.testsuite.url.N, where N is a numeric
       suffice; the same properties without the suffices are
       ignored by test-multijvm. As with the target test, if any
       of the com.mysql.jdbc.testsuite.jvm.N settings points to
       Java 5, then Ant relies on the property
       com.mysql.jdbc.jdk8 to run the tests specific to JDBC 4.0
       and later.
       You can choose to run individual test cases or specific
       tests by using the test or methods property, as explained
       in the last bullet for the target test. Each test is run
       once per possible combination of JVMs and server
       instances (that is, 6 times in total for in this
       example).
       When a test for a certain JVM-server combination has
       failed, test-multijvm does not throw an error, but moves
       on to the next combination, until all tests for all
       combinations are finished.

   While the test results are partially reported by the console,
   complete reports in HTML and XML formats are provided:

     * For results of test: view the HTML report by opening
       build/junit/unitregress/report/index.html. XML version of
       the reports are located in the folder
       build/junit/unitregress.

     * For results of test-multijvm: view the HTML report for
       each JVM-server combination by opening
       build/junit/MySQLN.server_version/operating_system_versio
       n/jvm-version/unitregress/report/index.html. XML version
       of the reports are located in the folder
       build/junit/MySQLN.server_version/operating_system_versio
       n/jvm-version/unitregress.

Chapter 4 Connector/J Examples

   Examples of using Connector/J are located throughout this
   document. This section provides a summary and links to these
   examples.

     * Example 6.1, "Connector/J: Obtaining a connection from
       the DriverManager"

     * Example 6.2, "Connector/J: Using java.sql.Statement to
       execute a SELECT query"

     * Example 6.3, "Connector/J: Calling Stored Procedures"

     * Example 6.3, "Connector/J: Using
       Connection.prepareCall()"

     * Example 6.3, "Connector/J: Registering output parameters"

     * Example 6.3, "Connector/J: Setting CallableStatement
       input parameters"

     * Example 6.3, "Connector/J: Retrieving results and output
       parameter values"

     * Example 6.4, "Connector/J: Retrieving AUTO_INCREMENT
       column values using Statement.getGeneratedKeys()"

     * Example 6.4, "Connector/J: Retrieving AUTO_INCREMENT
       column values using SELECT LAST_INSERT_ID()"

     * Example 6.4, "Connector/J: Retrieving AUTO_INCREMENT
       column values in Updatable ResultSets"

     * Example 7, "Connector/J: Using a connection pool with a
       J2EE application server"

     * Example 15, "Connector/J: Example of transaction with
       retry logic"

Chapter 5 Connector/J (JDBC) Reference

   This section of the manual contains reference material for
   MySQL Connector/J.

5.1 Driver/Datasource Class Names, URL Syntax and Configuration
Properties for Connector/J

   The name of the class that implements java.sql.Driver in
   MySQL Connector/J is com.mysql.jdbc.Driver. The
   org.gjt.mm.mysql.Driver class name is also usable for
   backward compatibility with MM.MySQL, the predecessor of
   Connector/J. Use this class name when registering the driver,
   or when configuring a software to use MySQL Connector/J.

JDBC URL Format

   The general format for a JDBC URL for connecting to a MySQL
   server is as follows, with items in square brackets ([ ])
   being optional:
jdbc:mysql://[host1][:port1][,[host2][:port2]]...[/[database]] ??
[?propertyName1=propertyValue1[&propertyName2=propertyValue2]...]

   Here is a simple example for a connection URL:
jdbc:mysql://localhost:3306/sakila?profileSQL=true

   Supply multiple hosts for a server failover setup (see
   Chapter 8, "Multi-Host Connections" for details):
# Connection URL for a server failover setup:
jdbc:mysql//primaryhost,secondaryhost1,secondaryhost2/test

   There are specialized URL schemes for configuring
   Connector/J's multi-host functions like load balancing and
   replication; here are some examples (see Chapter 8,
   "Multi-Host Connections" for details):
# Connection URL for load balancing:
jdbc:mysql:loadbalance://localhost:3306,localhost:3310/sakila

# Connection URL for server replication:
jdbc:mysql:replication://master,slave1,slave2,slave3/test

Host and Port

   If no hosts are not specified, the host name defaults to
   127.0.0.1. If the port for a host is not specified, it
   defaults to 3306, the default port number for MySQL servers.

Initial Database for Connection

   If the database is not specified, the connection is made with
   no default database. In this case, either call the
   setCatalog() method on the Connection instance, or fully
   specify table names using the database name (that is, SELECT
   dbname.tablename.colname FROM dbname.tablename...) in your
   SQL. Opening a connection without specifying the database to
   use is generally only useful when building tools that work
   with multiple databases, such as GUI database managers.
   Note

   Always use the Connection.setCatalog() method to specify the
   desired database in JDBC applications, rather than the USE
   database statement.

IPv6 Connections

   For IPv6 connections, use this alternative syntax to specify
   hosts in the URL (the same syntax can also be used for IPv4
   connections):
jdbc:mysql://address=(key1=value)[(key2=value)]...[,address=(key3=valu
e)[(key4=value)]...]...[/[database]]??
[?propertyName1=propertyValue1[&propertyName2=propertyValue2]...]

   Supported keys include:

     * (protocol=tcp), or (protocol=pipe) for named pipes on
       Windows.

     * (path=path_to_pipe) for named pipes.

     * (host=hostname) for TCP connections.

     * (port=port_number) for TCP connections.

   For example:
jdbc:mysql://address=(protocol=tcp)(host=localhost)(port=3306)/db

   Keys other than the four mentioned above are treated as
   host-specific configuration properties, which allow per-host
   overrides of any configuration property set for multi-host
   connections (that is, when using failover, load balancing, or
   replication). For example:
# IPv6 Connection URL for a server failover setup:
jdbc:mysql//address=(protocol=tcp)(host=primaryhost)(port=3306),??
address=(protocol=tcp)(host=secondaryhost1)(port=3310)(user=test2)/tes
t

# IPv6 Connection URL for load balancing:
jdbc:mysql:loadbalance://address=(protocol=tcp)(host=localhost)(port=3
306)(user=test1),??
address=(protocol=tcp)(host=localhost)(port=3310)(user=test2)/sakila

# IPv6 Connection URL for server replication:
jdbc:mysql:replication://address=(protocol=tcp)(host=master)(port=3306
)(user=test1),??
address=(protocol=tcp)(host=slave1)(port=3310)(user=test2)/test

   Limit the overrides to user, password, network timeouts, and
   statement and metadata cache sizes; the effects of other
   per-host overrides are not defined.

   The ways to set the other configuration properties are the
   same for IPv6 and IPv4 URLs; see Section 5.1, "."

Setting Configuration Properties

   Configuration properties define how Connector/J will make a
   connection to a MySQL server. Unless otherwise noted,
   properties can be set for a DataSource object or for a
   Connection object.

   Configuration properties can be set in one of the following
   ways:

     * Using the set*() methods on MySQL implementations of
       java.sql.DataSource (which is the preferred method when
       using implementations of java.sql.DataSource):

          + com.mysql.jdbc.jdbc2.optional.MysqlDataSource

          + com.mysql.jdbc.jdbc2.optional.MysqlConnectionPoolDat
            aSource

     * As a key/value pair in the java.util.Properties instance
       passed to DriverManager.getConnection() or
       Driver.connect()

     * As a JDBC URL parameter in the URL given to
       java.sql.DriverManager.getConnection(),
       java.sql.Driver.connect() or the MySQL implementations of
       the javax.sql.DataSource setURL() method. If you specify
       a configuration property in the URL without providing a
       value for it, nothing will be set; for example, adding
       useServerPrepStmts alone to the URL does not make
       Connector/J use server-side prepared statements; you need
       to add useServerPrepStmts=true.
       Note
       If the mechanism you use to configure a JDBC URL is
       XML-based, use the XML character literal &amp; to
       separate configuration parameters, as the ampersand is a
       reserved character for XML.

   The properties are listed in the following tables.

   Connection/Authentication.
   Properties and Descriptions

   user

   The user to connect as

   Since version: all versions

   password

   The password to use when connecting

   Since version: all versions

   socketFactory

   The name of the class that the driver should use for creating
   socket connections to the server. This class must implement
   the interface 'com.mysql.jdbc.SocketFactory' and have public
   no-args constructor.

   Default: com.mysql.jdbc.StandardSocketFactory

   Since version: 3.0.3

   connectTimeout

   Timeout for socket connect (in milliseconds), with 0 being no
   timeout. Only works on JDK-1.4 or newer. Defaults to '0'.

   Default: 0

   Since version: 3.0.1

   socketTimeout

   Timeout on network socket operations (0, the default means no
   timeout).

   Default: 0

   Since version: 3.0.1

   connectionLifecycleInterceptors

   A comma-delimited list of classes that implement
   "com.mysql.jdbc.ConnectionLifecycleInterceptor" that should
   notified of connection lifecycle events (creation,
   destruction, commit, rollback, setCatalog and setAutoCommit)
   and potentially alter the execution of these commands.
   ConnectionLifecycleInterceptors are "stackable", more than
   one interceptor may be specified via the configuration
   property as a comma-delimited list, with the interceptors
   executed in order from left to right.

   Since version: 5.1.4

   useConfigs

   Load the comma-delimited list of configuration properties
   before parsing the URL or applying user-specified properties.
   These configurations are explained in the 'Configurations' of
   the documentation.

   Since version: 3.1.5

   authenticationPlugins

   Comma-delimited list of classes that implement
   com.mysql.jdbc.AuthenticationPlugin and which will be used
   for authentication unless disabled by
   "disabledAuthenticationPlugins" property.

   Since version: 5.1.19

   defaultAuthenticationPlugin

   Name of a class implementing
   com.mysql.jdbc.AuthenticationPlugin which will be used as the
   default authentication plugin (see below). It is an error to
   use a class which is not listed in "authenticationPlugins"
   nor it is one of the built-in plugins. It is an error to set
   as default a plugin which was disabled with
   "disabledAuthenticationPlugins" property. It is an error to
   set this value to null or the empty string (i.e. there must
   be at least a valid default authentication plugin specified
   for the connection, meeting all constraints listed above).

   Default:
   com.mysql.jdbc.authentication.MysqlNativePasswordPlugin

   Since version: 5.1.19

   disabledAuthenticationPlugins

   Comma-delimited list of classes implementing
   com.mysql.jdbc.AuthenticationPlugin or mechanisms, i.e.
   "mysql_native_password". The authentication plugins or
   mechanisms listed will not be used for authentication which
   will fail if it requires one of them. It is an error to
   disable the default authentication plugin (either the one
   named by "defaultAuthenticationPlugin" property or the
   hard-coded one if "defaultAuthenticationPlugin" property is
   not set).

   Since version: 5.1.19

   disconnectOnExpiredPasswords

   If "disconnectOnExpiredPasswords" is set to "false" and
   password is expired then server enters "sandbox" mode and
   sends ERR(08001, ER_MUST_CHANGE_PASSWORD) for all commands
   that are not needed to set a new password until a new
   password is set.

   Default: true

   Since version: 5.1.23

   interactiveClient

   Set the CLIENT_INTERACTIVE flag, which tells MySQL to timeout
   connections based on INTERACTIVE_TIMEOUT instead of
   WAIT_TIMEOUT

   Default: false

   Since version: 3.1.0

   localSocketAddress

   Hostname or IP address given to explicitly configure the
   interface that the driver will bind the client side of the
   TCP/IP connection to when connecting.

   Since version: 5.0.5

   propertiesTransform

   An implementation of
   com.mysql.jdbc.ConnectionPropertiesTransform that the driver
   will use to modify URL properties passed to the driver before
   attempting a connection

   Since version: 3.1.4

   useCompression

   Use zlib compression when communicating with the server
   (true/false)? Defaults to 'false'.

   Default: false

   Since version: 3.0.17

   Networking.
   Properties and Descriptions

   socksProxyHost

   Name or IP address of SOCKS host to connect through.

   Since version: 5.1.34

   socksProxyPort

   Port of SOCKS server.

   Default: 1080

   Since version: 5.1.34

   maxAllowedPacket

   Maximum allowed packet size to send to server. If not set,
   the value of system variable 'max_allowed_packet' will be
   used to initialize this upon connecting. This value will not
   take effect if set larger than the value of
   'max_allowed_packet'. Also, due to an internal dependency
   with the property "blobSendChunkSize", this setting has a
   minimum value of "8203" if "useServerPrepStmts" is set to
   "true".

   Default: -1

   Since version: 5.1.8

   tcpKeepAlive

   If connecting using TCP/IP, should the driver set
   SO_KEEPALIVE?

   Default: true

   Since version: 5.0.7

   tcpNoDelay

   If connecting using TCP/IP, should the driver set
   SO_TCP_NODELAY (disabling the Nagle Algorithm)?

   Default: true

   Since version: 5.0.7

   tcpRcvBuf

   If connecting using TCP/IP, should the driver set SO_RCV_BUF
   to the given value? The default value of '0', means use the
   platform default value for this property)

   Default: 0

   Since version: 5.0.7

   tcpSndBuf

   If connecting using TCP/IP, should the driver set SO_SND_BUF
   to the given value? The default value of '0', means use the
   platform default value for this property)

   Default: 0

   Since version: 5.0.7

   tcpTrafficClass

   If connecting using TCP/IP, should the driver set traffic
   class or type-of-service fields ?See the documentation for
   java.net.Socket.setTrafficClass() for more information.

   Default: 0

   Since version: 5.0.7

   High Availability and Clustering.
   Properties and Descriptions

   autoReconnect

   Should the driver try to re-establish stale and/or dead
   connections? If enabled the driver will throw an exception
   for a queries issued on a stale or dead connection, which
   belong to the current transaction, but will attempt reconnect
   before the next query issued on the connection in a new
   transaction. The use of this feature is not recommended,
   because it has side effects related to session state and data
   consistency when applications don't handle SQLExceptions
   properly, and is only designed to be used when you are unable
   to configure your application to handle SQLExceptions
   resulting from dead and stale connections properly.
   Alternatively, as a last option, investigate setting the
   MySQL server variable "wait_timeout" to a high value, rather
   than the default of 8 hours.

   Default: false

   Since version: 1.1

   autoReconnectForPools

   Use a reconnection strategy appropriate for connection pools
   (defaults to 'false')

   Default: false

   Since version: 3.1.3

   failOverReadOnly

   When failing over in autoReconnect mode, should the
   connection be set to 'read-only'?

   Default: true

   Since version: 3.0.12

   maxReconnects

   Maximum number of reconnects to attempt if autoReconnect is
   true, default is '3'.

   Default: 3

   Since version: 1.1

   reconnectAtTxEnd

   If autoReconnect is set to true, should the driver attempt
   reconnections at the end of every transaction?

   Default: false

   Since version: 3.0.10

   retriesAllDown

   When using loadbalancing or failover, the number of times the
   driver should cycle through available hosts, attempting to
   connect. Between cycles, the driver will pause for 250ms if
   no servers are available.

   Default: 120

   Since version: 5.1.6

   initialTimeout

   If autoReconnect is enabled, the initial time to wait between
   re-connect attempts (in seconds, defaults to '2').

   Default: 2

   Since version: 1.1

   roundRobinLoadBalance

   When autoReconnect is enabled, and failoverReadonly is false,
   should we pick hosts to connect to on a round-robin basis?

   Default: false

   Since version: 3.1.2

   queriesBeforeRetryMaster

   Number of queries to issue before falling back to the primary
   host when failed over (when using multi-host failover).
   Whichever condition is met first, 'queriesBeforeRetryMaster'
   or 'secondsBeforeRetryMaster' will cause an attempt to be
   made to reconnect to the primary host. Setting both
   properties to 0 disables the automatic fall back to the
   primary host at transaction boundaries. Defaults to 50.

   Default: 50

   Since version: 3.0.2

   secondsBeforeRetryMaster

   How long should the driver wait, when failed over, before
   attempting to reconnect to the primary host? Whichever
   condition is met first, 'queriesBeforeRetryMaster' or
   'secondsBeforeRetryMaster' will cause an attempt to be made
   to reconnect to the master. Setting both properties to 0
   disables the automatic fall back to the primary host at
   transaction boundaries. Time in seconds, defaults to 30

   Default: 30

   Since version: 3.0.2

   allowMasterDownConnections

   By default, a replication-aware connection will fail to
   connect when configured master hosts are all unavailable at
   initial connection. Setting this property to 'true' allows to
   establish the initial connection, by failing over to the
   slave servers, in read-only state. It won't prevent
   subsequent failures when switching back to the master hosts
   i.e. by setting the replication connection to read/write
   state.

   Default: false

   Since version: 5.1.27

   allowSlaveDownConnections

   By default, a replication-aware connection will fail to
   connect when configured slave hosts are all unavailable at
   initial connection. Setting this property to 'true' allows to
   establish the initial connection. It won't prevent failures
   when switching to slaves i.e. by setting the replication
   connection to read-only state. The property
   'readFromMasterWhenNoSlaves' should be used for this purpose.

   Default: false

   Since version: 5.1.38

   readFromMasterWhenNoSlaves

   Replication-aware connections distribute load by using the
   master hosts when in read/write state and by using the slave
   hosts when in read-only state. If, when setting the
   connection to read-only state, none of the slave hosts are
   available, an SQLExeception is thrown back. Setting this
   property to 'true' allows to fail over to the master hosts,
   while setting the connection state to read-only, when no
   slave hosts are available at switch instant.

   Default: false

   Since version: 5.1.38

   replicationEnableJMX

   Enables JMX-based management of load-balanced connection
   groups, including live addition/removal of hosts from
   load-balancing pool.

   Default: false

   Since version: 5.1.27

   selfDestructOnPingMaxOperations

   =If set to a non-zero value, the driver will report close the
   connection and report failure when Connection.ping() or
   Connection.isValid(int) is called if the connection's count
   of commands sent to the server exceeds this value.

   Default: 0

   Since version: 5.1.6

   selfDestructOnPingSecondsLifetime

   If set to a non-zero value, the driver will report close the
   connection and report failure when Connection.ping() or
   Connection.isValid(int) is called if the connection's
   lifetime exceeds this value.

   Default: 0

   Since version: 5.1.6

   resourceId

   A globally unique name that identifies the resource that this
   datasource or connection is connected to, used for
   XAResource.isSameRM() when the driver can't determine this
   value based on hostnames used in the URL

   Since version: 5.0.1

   Security.
   Properties and Descriptions

   allowMultiQueries

   Allow the use of ';' to delimit multiple queries during one
   statement (true/false), defaults to 'false', and does not
   affect the addBatch() and executeBatch() methods, which
   instead rely on rewriteBatchStatements.

   Default: false

   Since version: 3.1.1

   useSSL

   Use SSL when communicating with the server (true/false),
   default is 'true' when connecting to MySQL 5.5.45+, 5.6.26+
   or 5.7.6+, otherwise default is 'false'

   Default: false

   Since version: 3.0.2

   requireSSL

   Require server support of SSL connection if useSSL=true?
   (defaults to 'false').

   Default: false

   Since version: 3.1.0

   verifyServerCertificate

   If "useSSL" is set to "true", should the driver verify the
   server's certificate? When using this feature, the keystore
   parameters should be specified by the
   "clientCertificateKeyStore*" properties, rather than system
   properties. Default is 'false' when connecting to MySQL
   5.5.45+, 5.6.26+ or 5.7.6+ and "useSSL" was not explicitly
   set to "true". Otherwise default is 'true'

   Default: true

   Since version: 5.1.6

   clientCertificateKeyStoreUrl

   URL to the client certificate KeyStore (if not specified, use
   defaults)

   Since version: 5.1.0

   clientCertificateKeyStoreType

   KeyStore type for client certificates (NULL or empty means
   use the default, which is "JKS". Standard keystore types
   supported by the JVM are "JKS" and "PKCS12", your environment
   may have more available depending on what security products
   are installed and available to the JVM.

   Default: JKS

   Since version: 5.1.0

   clientCertificateKeyStorePassword

   Password for the client certificates KeyStore

   Since version: 5.1.0

   trustCertificateKeyStoreUrl

   URL to the trusted root certificate KeyStore (if not
   specified, use defaults)

   Since version: 5.1.0

   trustCertificateKeyStoreType

   KeyStore type for trusted root certificates (NULL or empty
   means use the default, which is "JKS". Standard keystore
   types supported by the JVM are "JKS" and "PKCS12", your
   environment may have more available depending on what
   security products are installed and available to the JVM.

   Default: JKS

   Since version: 5.1.0

   trustCertificateKeyStorePassword

   Password for the trusted root certificates KeyStore

   Since version: 5.1.0

   enabledSSLCipherSuites

   If "useSSL" is set to "true", overrides the cipher suites
   enabled for use on the underlying SSL sockets. This may be
   required when using external JSSE providers or to specify
   cipher suites compatible with both MySQL server and used JVM.

   Since version: 5.1.35

   allowLoadLocalInfile

   Should the driver allow use of 'LOAD DATA LOCAL INFILE...'
   (defaults to 'true').

   Default: true

   Since version: 3.0.3

   allowUrlInLocalInfile

   Should the driver allow URLs in 'LOAD DATA LOCAL INFILE'
   statements?

   Default: false

   Since version: 3.1.4

   allowPublicKeyRetrieval

   Allows special handshake roundtrip to get server RSA public
   key directly from server.

   Default: false

   Since version: 5.1.31

   paranoid

   Take measures to prevent exposure sensitive information in
   error messages and clear data structures holding sensitive
   data when possible? (defaults to 'false')

   Default: false

   Since version: 3.0.1

   passwordCharacterEncoding

   What character encoding is used for passwords? Leaving this
   set to the default value (null), uses the value set in
   "characterEncoding" if there is one, otherwise uses UTF-8 as
   default encoding. If the password contains non-ASCII
   characters, the password encoding must match what server
   encoding was set to when the password was created. For
   passwords in other character encodings, the encoding will
   have to be specified with this property (or with
   "characterEncoding"), as it's not possible for the driver to
   auto-detect this.

   Since version: 5.1.7

   serverRSAPublicKeyFile

   File path to the server RSA public key file for
   sha256_password authentication. If not specified, the public
   key will be retrieved from the server.

   Since version: 5.1.31

   Performance Extensions.
   Properties and Descriptions

   callableStmtCacheSize

   If 'cacheCallableStmts' is enabled, how many callable
   statements should be cached?

   Default: 100

   Since version: 3.1.2

   metadataCacheSize

   The number of queries to cache ResultSetMetadata for if
   cacheResultSetMetaData is set to 'true' (default 50)

   Default: 50

   Since version: 3.1.1

   useLocalSessionState

   Should the driver refer to the internal values of autocommit
   and transaction isolation that are set by
   Connection.setAutoCommit() and
   Connection.setTransactionIsolation() and transaction state as
   maintained by the protocol, rather than querying the database
   or blindly sending commands to the database for commit() or
   rollback() method calls?

   Default: false

   Since version: 3.1.7

   useLocalTransactionState

   Should the driver use the in-transaction state provided by
   the MySQL protocol to determine if a commit() or rollback()
   should actually be sent to the database?

   Default: false

   Since version: 5.1.7

   prepStmtCacheSize

   If prepared statement caching is enabled, how many prepared
   statements should be cached?

   Default: 25

   Since version: 3.0.10

   prepStmtCacheSqlLimit

   If prepared statement caching is enabled, what's the largest
   SQL the driver will cache the parsing for?

   Default: 256

   Since version: 3.0.10

   parseInfoCacheFactory

   Name of a class implementing
   com.mysql.jdbc.CacheAdapterFactory, which will be used to
   create caches for the parsed representation of client-side
   prepared statements.

   Default: com.mysql.jdbc.PerConnectionLRUFactory

   Since version: 5.1.1

   serverConfigCacheFactory

   Name of a class implementing
   com.mysql.jdbc.CacheAdapterFactory<String, Map<String,
   String>>, which will be used to create caches for MySQL
   server configuration values

   Default: com.mysql.jdbc.PerVmServerConfigCacheFactory

   Since version: 5.1.1

   alwaysSendSetIsolation

   Should the driver always communicate with the database when
   Connection.setTransactionIsolation() is called? If set to
   false, the driver will only communicate with the database
   when the requested transaction isolation is different than
   the whichever is newer, the last value that was set via
   Connection.setTransactionIsolation(), or the value that was
   read from the server when the connection was established.
   Note that useLocalSessionState=true will force the same
   behavior as alwaysSendSetIsolation=false, regardless of how
   alwaysSendSetIsolation is set.

   Default: true

   Since version: 3.1.7

   maintainTimeStats

   Should the driver maintain various internal timers to enable
   idle time calculations as well as more verbose error messages
   when the connection to the server fails? Setting this
   property to false removes at least two calls to
   System.getCurrentTimeMillis() per query.

   Default: true

   Since version: 3.1.9

   useCursorFetch

   If connected to MySQL > 5.0.2, and setFetchSize() > 0 on a
   statement, should that statement use cursor-based fetching to
   retrieve rows?

   Default: false

   Since version: 5.0.0

   blobSendChunkSize

   Chunk size to use when sending BLOB/CLOBs via
   ServerPreparedStatements. Note that this value cannot exceed
   the value of "maxAllowedPacket" and, if that is the case,
   then this value will be corrected automatically.

   Default: 1048576

   Since version: 3.1.9

   cacheCallableStmts

   Should the driver cache the parsing stage of
   CallableStatements

   Default: false

   Since version: 3.1.2

   cachePrepStmts

   Should the driver cache the parsing stage of
   PreparedStatements of client-side prepared statements, the
   "check" for suitability of server-side prepared and
   server-side prepared statements themselves?

   Default: false

   Since version: 3.0.10

   cacheResultSetMetadata

   Should the driver cache ResultSetMetaData for Statements and
   PreparedStatements? (Req. JDK-1.4+, true/false, default
   'false')

   Default: false

   Since version: 3.1.1

   cacheServerConfiguration

   Should the driver cache the results of 'SHOW VARIABLES' and
   'SHOW COLLATION' on a per-URL basis?

   Default: false

   Since version: 3.1.5

   defaultFetchSize

   The driver will call setFetchSize(n) with this value on all
   newly-created Statements

   Default: 0

   Since version: 3.1.9

   dontCheckOnDuplicateKeyUpdateInSQL

   Stops checking if every INSERT statement contains the "ON
   DUPLICATE KEY UPDATE" clause. As a side effect, obtaining the
   statement's generated keys information will return a list
   where normally it wouldn't. Also be aware that, in this case,
   the list of generated keys returned may not be accurate. The
   effect of this property is canceled if set simultaneously
   with 'rewriteBatchedStatements=true'.

   Default: false

   Since version: 5.1.32

   dontTrackOpenResources

   The JDBC specification requires the driver to automatically
   track and close resources, however if your application
   doesn't do a good job of explicitly calling close() on
   statements or result sets, this can cause memory leakage.
   Setting this property to true relaxes this constraint, and
   can be more memory efficient for some applications. Also the
   automatic closing of the Statement and current ResultSet in
   Statement.closeOnCompletion() and Statement.getMoreResults
   ([Statement.CLOSE_CURRENT_RESULT |
   Statement.CLOSE_ALL_RESULTS]), respectively, ceases to
   happen. This property automatically sets
   holdResultsOpenOverStatementClose=true.

   Default: false

   Since version: 3.1.7

   dynamicCalendars

   Should the driver retrieve the default calendar when
   required, or cache it per connection/session?

   Default: false

   Since version: 3.1.5

   elideSetAutoCommits

   If using MySQL-4.1 or newer, should the driver only issue
   'set autocommit=n' queries when the server's state doesn't
   match the requested state by
   Connection.setAutoCommit(boolean)?

   Default: false

   Since version: 3.1.3

   enableEscapeProcessing

   Sets the default escape processing behavior for Statement
   objects. The method Statement.setEscapeProcessing() can be
   used to specify the escape processing behavior for an
   individual Statement object. Default escape processing
   behavior in prepared statements must be defined with the
   property 'processEscapeCodesForPrepStmts'.

   Default: true

   Since version: 5.1.37

   enableQueryTimeouts

   When enabled, query timeouts set via
   Statement.setQueryTimeout() use a shared java.util.Timer
   instance for scheduling. Even if the timeout doesn't expire
   before the query is processed, there will be memory used by
   the TimerTask for the given timeout which won't be reclaimed
   until the time the timeout would have expired if it hadn't
   been cancelled by the driver. High-load environments might
   want to consider disabling this functionality.

   Default: true

   Since version: 5.0.6

   holdResultsOpenOverStatementClose

   Should the driver close result sets on Statement.close() as
   required by the JDBC specification?

   Default: false

   Since version: 3.1.7

   largeRowSizeThreshold

   What size result set row should the JDBC driver consider
   "large", and thus use a more memory-efficient way of
   representing the row internally?

   Default: 2048

   Since version: 5.1.1

   loadBalanceStrategy

   If using a load-balanced connection to connect to SQL nodes
   in a MySQL Cluster/NDB configuration (by using the URL prefix
   "jdbc:mysql:loadbalance://"), which load balancing algorithm
   should the driver use: (1) "random" - the driver will pick a
   random host for each request. This tends to work better than
   round-robin, as the randomness will somewhat account for
   spreading loads where requests vary in response time, while
   round-robin can sometimes lead to overloaded nodes if there
   are variations in response times across the workload. (2)
   "bestResponseTime" - the driver will route the request to the
   host that had the best response time for the previous
   transaction.

   Default: random

   Since version: 5.0.6

   locatorFetchBufferSize

   If 'emulateLocators' is configured to 'true', what size
   buffer should be used when fetching BLOB data for
   getBinaryInputStream?

   Default: 1048576

   Since version: 3.2.1

   readOnlyPropagatesToServer

   Should the driver issue appropriate statements to implicitly
   set the transaction access mode on server side when
   Connection.setReadOnly() is called? Setting this property to
   'true' enables InnoDB read-only potential optimizations but
   also requires an extra roundtrip to set the right transaction
   state. Even if this property is set to 'false', the driver
   will do its best effort to prevent the execution of
   database-state-changing queries. Requires minimum of MySQL
   5.6.

   Default: true

   Since version: 5.1.35

   rewriteBatchedStatements

   Should the driver use multiqueries (irregardless of the
   setting of "allowMultiQueries") as well as rewriting of
   prepared statements for INSERT into multi-value inserts when
   executeBatch() is called? Notice that this has the potential
   for SQL injection if using plain java.sql.Statements and your
   code doesn't sanitize input correctly. Notice that for
   prepared statements, server-side prepared statements can not
   currently take advantage of this rewrite option, and that if
   you don't specify stream lengths when using
   PreparedStatement.set*Stream(), the driver won't be able to
   determine the optimum number of parameters per batch and you
   might receive an error from the driver that the resultant
   packet is too large. Statement.getGeneratedKeys() for these
   rewritten statements only works when the entire batch
   includes INSERT statements. Please be aware using
   rewriteBatchedStatements=true with INSERT .. ON DUPLICATE KEY
   UPDATE that for rewritten statement server returns only one
   value as sum of all affected (or found) rows in batch and it
   isn't possible to map it correctly to initial statements; in
   this case driver returns 0 as a result of each batch
   statement if total count was 0, and the
   Statement.SUCCESS_NO_INFO as a result of each batch statement
   if total count was > 0.

   Default: false

   Since version: 3.1.13

   useDirectRowUnpack

   Use newer result set row unpacking code that skips a copy
   from network buffers to a MySQL packet instance and instead
   reads directly into the result set row data buffers.

   Default: true

   Since version: 5.1.1

   useDynamicCharsetInfo

   Should the driver use a per-connection cache of character set
   information queried from the server when necessary, or use a
   built-in static mapping that is more efficient, but isn't
   aware of custom character sets or character sets implemented
   after the release of the JDBC driver?

   Default: true

   Since version: 5.0.6

   useFastDateParsing

   Use internal String->Date/Time/Timestamp conversion routines
   to avoid excessive object creation? This is part of the
   legacy date-time code, thus the property has an effect only
   when "useLegacyDatetimeCode=true."

   Default: true

   Since version: 5.0.5

   useFastIntParsing

   Use internal String->Integer conversion routines to avoid
   excessive object creation?

   Default: true

   Since version: 3.1.4

   useJvmCharsetConverters

   Always use the character encoding routines built into the
   JVM, rather than using lookup tables for single-byte
   character sets?

   Default: false

   Since version: 5.0.1

   useReadAheadInput

   Use newer, optimized non-blocking, buffered input stream when
   reading from the server?

   Default: true

   Since version: 3.1.5

   Debugging/Profiling.
   Properties and Descriptions

   logger

   The name of a class that implements "com.mysql.jdbc.log.Log"
   that will be used to log messages to. (default is
   "com.mysql.jdbc.log.StandardLogger", which logs to STDERR)

   Default: com.mysql.jdbc.log.StandardLogger

   Since version: 3.1.1

   gatherPerfMetrics

   Should the driver gather performance metrics, and report them
   via the configured logger every 'reportMetricsIntervalMillis'
   milliseconds?

   Default: false

   Since version: 3.1.2

   profileSQL

   Trace queries and their execution/fetch times to the
   configured logger (true/false) defaults to 'false'

   Default: false

   Since version: 3.1.0

   profileSql

   Deprecated, use 'profileSQL' instead. Trace queries and their
   execution/fetch times on STDERR (true/false) defaults to
   'false'

   Since version: 2.0.14

   reportMetricsIntervalMillis

   If 'gatherPerfMetrics' is enabled, how often should they be
   logged (in ms)?

   Default: 30000

   Since version: 3.1.2

   maxQuerySizeToLog

   Controls the maximum length/size of a query that will get
   logged when profiling or tracing

   Default: 2048

   Since version: 3.1.3

   packetDebugBufferSize

   The maximum number of packets to retain when
   'enablePacketDebug' is true

   Default: 20

   Since version: 3.1.3

   slowQueryThresholdMillis

   If 'logSlowQueries' is enabled, how long should a query (in
   ms) before it is logged as 'slow'?

   Default: 2000

   Since version: 3.1.2

   slowQueryThresholdNanos

   If 'useNanosForElapsedTime' is set to true, and this property
   is set to a non-zero value, the driver will use this
   threshold (in nanosecond units) to determine if a query was
   slow.

   Default: 0

   Since version: 5.0.7

   useUsageAdvisor

   Should the driver issue 'usage' warnings advising proper and
   efficient usage of JDBC and MySQL Connector/J to the log
   (true/false, defaults to 'false')?

   Default: false

   Since version: 3.1.1

   autoGenerateTestcaseScript

   Should the driver dump the SQL it is executing, including
   server-side prepared statements to STDERR?

   Default: false

   Since version: 3.1.9

   autoSlowLog

   Instead of using slowQueryThreshold* to determine if a query
   is slow enough to be logged, maintain statistics that allow
   the driver to determine queries that are outside the 99th
   percentile?

   Default: true

   Since version: 5.1.4

   clientInfoProvider

   The name of a class that implements the
   com.mysql.jdbc.JDBC4ClientInfoProvider interface in order to
   support JDBC-4.0's Connection.get/setClientInfo() methods

   Default: com.mysql.jdbc.JDBC4CommentClientInfoProvider

   Since version: 5.1.0

   dumpMetadataOnColumnNotFound

   Should the driver dump the field-level metadata of a result
   set into the exception message when ResultSet.findColumn()
   fails?

   Default: false

   Since version: 3.1.13

   dumpQueriesOnException

   Should the driver dump the contents of the query sent to the
   server in the message for SQLExceptions?

   Default: false

   Since version: 3.1.3

   enablePacketDebug

   When enabled, a ring-buffer of 'packetDebugBufferSize'
   packets will be kept, and dumped when exceptions are thrown
   in key areas in the driver's code

   Default: false

   Since version: 3.1.3

   explainSlowQueries

   If 'logSlowQueries' is enabled, should the driver
   automatically issue an 'EXPLAIN' on the server and send the
   results to the configured log at a WARN level?

   Default: false

   Since version: 3.1.2

   includeInnodbStatusInDeadlockExceptions

   Include the output of "SHOW ENGINE INNODB STATUS" in
   exception messages when deadlock exceptions are detected?

   Default: false

   Since version: 5.0.7

   includeThreadDumpInDeadlockExceptions

   Include a current Java thread dump in exception messages when
   deadlock exceptions are detected?

   Default: false

   Since version: 5.1.15

   includeThreadNamesAsStatementComment

   Include the name of the current thread as a comment visible
   in "SHOW PROCESSLIST", or in Innodb deadlock dumps, useful in
   correlation with
   "includeInnodbStatusInDeadlockExceptions=true" and
   "includeThreadDumpInDeadlockExceptions=true".

   Default: false

   Since version: 5.1.15

   logSlowQueries

   Should queries that take longer than
   'slowQueryThresholdMillis' be logged?

   Default: false

   Since version: 3.1.2

   logXaCommands

   Should the driver log XA commands sent by MysqlXaConnection
   to the server, at the DEBUG level of logging?

   Default: false

   Since version: 5.0.5

   profilerEventHandler

   Name of a class that implements the interface
   com.mysql.jdbc.profiler.ProfilerEventHandler that will be
   used to handle profiling/tracing events.

   Default: com.mysql.jdbc.profiler.LoggingProfilerEventHandler

   Since version: 5.1.6

   resultSetSizeThreshold

   If the usage advisor is enabled, how many rows should a
   result set contain before the driver warns that it is
   suspiciously large?

   Default: 100

   Since version: 5.0.5

   traceProtocol

   Should trace-level network protocol be logged?

   Default: false

   Since version: 3.1.2

   useNanosForElapsedTime

   For profiling/debugging functionality that measures elapsed
   time, should the driver try to use nanoseconds resolution if
   available (JDK >= 1.5)?

   Default: false

   Since version: 5.0.7

   Miscellaneous.
   Properties and Descriptions

   useUnicode

   Should the driver use Unicode character encodings when
   handling strings? Should only be used when the driver can't
   determine the character set mapping, or you are trying to
   'force' the driver to use a character set that MySQL either
   doesn't natively support (such as UTF-8), true/false,
   defaults to 'true'

   Default: true

   Since version: 1.1g

   characterEncoding

   If 'useUnicode' is set to true, what character encoding
   should the driver use when dealing with strings? (defaults is
   to 'autodetect')

   Since version: 1.1g

   characterSetResults

   Character set to tell the server to return results as.

   Since version: 3.0.13

   connectionAttributes

   A comma-delimited list of user-defined key:value pairs (in
   addition to standard MySQL-defined key:value pairs) to be
   passed to MySQL Server for display as connection attributes
   in the PERFORMANCE_SCHEMA.SESSION_CONNECT_ATTRS table.
   Example usage: connectionAttributes=key1:value1,key2:value2
   This functionality is available for use with MySQL Server
   version 5.6 or later only. Earlier versions of MySQL Server
   do not support connection attributes, causing this
   configuration option to be ignored. Setting
   connectionAttributes=none will cause connection attribute
   processing to be bypassed, for situations where Connection
   creation/initialization speed is critical.

   Since version: 5.1.25

   connectionCollation

   If set, tells the server to use this collation via 'set
   collation_connection'

   Since version: 3.0.13

   useBlobToStoreUTF8OutsideBMP

   Tells the driver to treat [MEDIUM/LONG]BLOB columns as
   [LONG]VARCHAR columns holding text encoded in UTF-8 that has
   characters outside the BMP (4-byte encodings), which MySQL
   server can't handle natively.

   Default: false

   Since version: 5.1.3

   utf8OutsideBmpExcludedColumnNamePattern

   When "useBlobToStoreUTF8OutsideBMP" is set to "true", column
   names matching the given regex will still be treated as BLOBs
   unless they match the regex specified for
   "utf8OutsideBmpIncludedColumnNamePattern". The regex must
   follow the patterns used for the java.util.regex package.

   Since version: 5.1.3

   utf8OutsideBmpIncludedColumnNamePattern

   Used to specify exclusion rules to
   "utf8OutsideBmpExcludedColumnNamePattern". The regex must
   follow the patterns used for the java.util.regex package.

   Since version: 5.1.3

   loadBalanceEnableJMX

   Enables JMX-based management of load-balanced connection
   groups, including live addition/removal of hosts from
   load-balancing pool.

   Default: false

   Since version: 5.1.13

   sessionVariables

   A comma-separated list of name/value pairs to be sent as SET
   SESSION ... to the server when the driver connects.

   Since version: 3.1.8

   useColumnNamesInFindColumn

   Prior to JDBC-4.0, the JDBC specification had a bug related
   to what could be given as a "column name" to ResultSet
   methods like findColumn(), or getters that took a String
   property. JDBC-4.0 clarified "column name" to mean the label,
   as given in an "AS" clause and returned by
   ResultSetMetaData.getColumnLabel(), and if no AS clause, the
   column name. Setting this property to "true" will give
   behavior that is congruent to JDBC-3.0 and earlier versions
   of the JDBC specification, but which because of the
   specification bug could give unexpected results. This
   property is preferred over "useOldAliasMetadataBehavior"
   unless you need the specific behavior that it provides with
   respect to ResultSetMetadata.

   Default: false

   Since version: 5.1.7

   allowNanAndInf

   Should the driver allow NaN or +/- INF values in
   PreparedStatement.setDouble()?

   Default: false

   Since version: 3.1.5

   autoClosePStmtStreams

   Should the driver automatically call .close() on
   streams/readers passed as arguments via set*() methods?

   Default: false

   Since version: 3.1.12

   autoDeserialize

   Should the driver automatically detect and de-serialize
   objects stored in BLOB fields?

   Default: false

   Since version: 3.1.5

   blobsAreStrings

   Should the driver always treat BLOBs as Strings -
   specifically to work around dubious metadata returned by the
   server for GROUP BY clauses?

   Default: false

   Since version: 5.0.8

   cacheDefaultTimezone

   Caches client's default time zone. This results in better
   performance when dealing with time zone conversions in Date
   and Time data types, however it won't be aware of time zone
   changes if they happen at runtime.

   Default: true

   Since version: 5.1.35

   capitalizeTypeNames

   Capitalize type names in DatabaseMetaData? (usually only
   useful when using WebObjects, true/false, defaults to
   'false')

   Default: true

   Since version: 2.0.7

   clobCharacterEncoding

   The character encoding to use for sending and retrieving
   TEXT, MEDIUMTEXT and LONGTEXT values instead of the
   configured connection characterEncoding

   Since version: 5.0.0

   clobberStreamingResults

   This will cause a 'streaming' ResultSet to be automatically
   closed, and any outstanding data still streaming from the
   server to be discarded if another query is executed before
   all the data has been read from the server.

   Default: false

   Since version: 3.0.9

   compensateOnDuplicateKeyUpdateCounts

   Should the driver compensate for the update counts of "ON
   DUPLICATE KEY" INSERT statements (2 = 1, 0 = 1) when using
   prepared statements?

   Default: false

   Since version: 5.1.7

   continueBatchOnError

   Should the driver continue processing batch commands if one
   statement fails. The JDBC spec allows either way (defaults to
   'true').

   Default: true

   Since version: 3.0.3

   createDatabaseIfNotExist

   Creates the database given in the URL if it doesn't yet
   exist. Assumes the configured user has permissions to create
   databases.

   Default: false

   Since version: 3.1.9

   detectCustomCollations

   Should the driver detect custom charsets/collations installed
   on server (true/false, defaults to 'false'). If this option
   set to 'true' driver gets actual charsets/collations from
   server each time connection establishes. This could slow down
   connection initialization significantly.

   Default: false

   Since version: 5.1.29

   emptyStringsConvertToZero

   Should the driver allow conversions from empty string fields
   to numeric values of '0'?

   Default: true

   Since version: 3.1.8

   emulateLocators

   Should the driver emulate java.sql.Blobs with locators? With
   this feature enabled, the driver will delay loading the
   actual Blob data until the one of the retrieval methods
   (getInputStream(), getBytes(), and so forth) on the blob data
   stream has been accessed. For this to work, you must use a
   column alias with the value of the column to the actual name
   of the Blob. The feature also has the following restrictions:
   The SELECT that created the result set must reference only
   one table, the table must have a primary key; the SELECT must
   alias the original blob column name, specified as a string,
   to an alternate name; the SELECT must cover all columns that
   make up the primary key.

   Default: false

   Since version: 3.1.0

   emulateUnsupportedPstmts

   Should the driver detect prepared statements that are not
   supported by the server, and replace them with client-side
   emulated versions?

   Default: true

   Since version: 3.1.7

   exceptionInterceptors

   Comma-delimited list of classes that implement
   com.mysql.jdbc.ExceptionInterceptor. These classes will be
   instantiated one per Connection instance, and all
   SQLExceptions thrown by the driver will be allowed to be
   intercepted by these interceptors, in a chained fashion, with
   the first class listed as the head of the chain.

   Since version: 5.1.8

   functionsNeverReturnBlobs

   Should the driver always treat data from functions returning
   BLOBs as Strings - specifically to work around dubious
   metadata returned by the server for GROUP BY clauses?

   Default: false

   Since version: 5.0.8

   generateSimpleParameterMetadata

   Should the driver generate simplified parameter metadata for
   PreparedStatements when no metadata is available either
   because the server couldn't support preparing the statement,
   or server-side prepared statements are disabled?

   Default: false

   Since version: 5.0.5

   getProceduresReturnsFunctions

   Pre-JDBC4 DatabaseMetaData API has only the getProcedures()
   and getProcedureColumns() methods, so they return metadata
   info for both stored procedures and functions. JDBC4 was
   extended with the getFunctions() and getFunctionColumns()
   methods and the expected behaviours of previous methods are
   not well defined. For JDBC4 and higher, default 'true' value
   of the option means that calls of
   DatabaseMetaData.getProcedures() and
   DatabaseMetaData.getProcedureColumns() return metadata for
   both procedures and functions as before, keeping backward
   compatibility. Setting this property to 'false' decouples
   Connector/J from its pre-JDBC4 behaviours for
   DatabaseMetaData.getProcedures() and
   DatabaseMetaData.getProcedureColumns(), forcing them to
   return metadata for procedures only.

   Default: true

   Since version: 5.1.26

   ignoreNonTxTables

   Ignore non-transactional table warning for rollback?
   (defaults to 'false').

   Default: false

   Since version: 3.0.9

   jdbcCompliantTruncation

   Should the driver throw java.sql.DataTruncation exceptions
   when data is truncated as is required by the JDBC
   specification when connected to a server that supports
   warnings (MySQL 4.1.0 and newer)? This property has no effect
   if the server sql-mode includes STRICT_TRANS_TABLES.

   Default: true

   Since version: 3.1.2

   loadBalanceAutoCommitStatementRegex

   When load-balancing is enabled for auto-commit statements
   (via loadBalanceAutoCommitStatementThreshold), the statement
   counter will only increment when the SQL matches the regular
   expression. By default, every statement issued matches.

   Since version: 5.1.15

   loadBalanceAutoCommitStatementThreshold

   When auto-commit is enabled, the number of statements which
   should be executed before triggering load-balancing to
   rebalance. Default value of 0 causes load-balanced
   connections to only rebalance when exceptions are
   encountered, or auto-commit is disabled and transactions are
   explicitly committed or rolled back.

   Default: 0

   Since version: 5.1.15

   loadBalanceBlacklistTimeout

   Time in milliseconds between checks of servers which are
   unavailable, by controlling how long a server lives in the
   global blacklist.

   Default: 0

   Since version: 5.1.0

   loadBalanceConnectionGroup

   Logical group of load-balanced connections within a
   classloader, used to manage different groups independently.
   If not specified, live management of load-balanced
   connections is disabled.

   Since version: 5.1.13

   loadBalanceExceptionChecker

   Fully-qualified class name of custom exception checker. The
   class must implement
   com.mysql.jdbc.LoadBalanceExceptionChecker interface, and is
   used to inspect SQLExceptions and determine whether they
   should trigger fail-over to another host in a load-balanced
   deployment.

   Default: com.mysql.jdbc.StandardLoadBalanceExceptionChecker

   Since version: 5.1.13

   loadBalancePingTimeout

   Time in milliseconds to wait for ping response from each of
   load-balanced physical connections when using load-balanced
   Connection.

   Default: 0

   Since version: 5.1.13

   loadBalanceSQLExceptionSubclassFailover

   Comma-delimited list of classes/interfaces used by default
   load-balanced exception checker to determine whether a given
   SQLException should trigger failover. The comparison is done
   using Class.isInstance(SQLException) using the thrown
   SQLException.

   Since version: 5.1.13

   loadBalanceSQLStateFailover

   Comma-delimited list of SQLState codes used by default
   load-balanced exception checker to determine whether a given
   SQLException should trigger failover. The SQLState of a given
   SQLException is evaluated to determine whether it begins with
   any value in the comma-delimited list.

   Since version: 5.1.13

   loadBalanceValidateConnectionOnSwapServer

   Should the load-balanced Connection explicitly check whether
   the connection is live when swapping to a new physical
   connection at commit/rollback?

   Default: false

   Since version: 5.1.13

   maxRows

   The maximum number of rows to return (0, the default means
   return all rows).

   Default: -1

   Since version: all versions

   netTimeoutForStreamingResults

   What value should the driver automatically set the server
   setting 'net_write_timeout' to when the streaming result sets
   feature is in use? (value has unit of seconds, the value '0'
   means the driver will not try and adjust this value)

   Default: 600

   Since version: 5.1.0

   noAccessToProcedureBodies

   When determining procedure parameter types for
   CallableStatements, and the connected user can't access
   procedure bodies through "SHOW CREATE PROCEDURE" or select on
   mysql.proc should the driver instead create basic metadata
   (all parameters reported as IN VARCHARs, but allowing
   registerOutParameter() to be called on them anyway) instead
   of throwing an exception?

   Default: false

   Since version: 5.0.3

   noDatetimeStringSync

   Don't ensure that
   ResultSet.getDatetimeType().toString().equals(ResultSet.getSt
   ring())

   Default: false

   Since version: 3.1.7

   noTimezoneConversionForDateType

   Don't convert DATE values using the server time zone if
   'useTimezone'='true' or 'useLegacyDatetimeCode'='false'

   Default: true

   Since version: 5.1.35

   noTimezoneConversionForTimeType

   Don't convert TIME values using the server time zone if
   'useTimezone'='true'

   Default: false

   Since version: 5.0.0

   nullCatalogMeansCurrent

   When DatabaseMetadataMethods ask for a 'catalog' parameter,
   does the value null mean use the current catalog? (this is
   not JDBC-compliant, but follows legacy behavior from earlier
   versions of the driver)

   Default: true

   Since version: 3.1.8

   nullNamePatternMatchesAll

   Should DatabaseMetaData methods that accept *pattern
   parameters treat null the same as '%' (this is not
   JDBC-compliant, however older versions of the driver accepted
   this departure from the specification)

   Default: true

   Since version: 3.1.8

   overrideSupportsIntegrityEnhancementFacility

   Should the driver return "true" for
   DatabaseMetaData.supportsIntegrityEnhancementFacility() even
   if the database doesn't support it to workaround applications
   that require this method to return "true" to signal support
   of foreign keys, even though the SQL specification states
   that this facility contains much more than just foreign key
   support (one such application being OpenOffice)?

   Default: false

   Since version: 3.1.12

   padCharsWithSpace

   If a result set column has the CHAR type and the value does
   not fill the amount of characters specified in the DDL for
   the column, should the driver pad the remaining characters
   with space (for ANSI compliance)?

   Default: false

   Since version: 5.0.6

   pedantic

   Follow the JDBC spec to the letter.

   Default: false

   Since version: 3.0.0

   pinGlobalTxToPhysicalConnection

   When using XAConnections, should the driver ensure that
   operations on a given XID are always routed to the same
   physical connection? This allows the XAConnection to support
   "XA START ... JOIN" after "XA END" has been called

   Default: false

   Since version: 5.0.1

   populateInsertRowWithDefaultValues

   When using ResultSets that are CONCUR_UPDATABLE, should the
   driver pre-populate the "insert" row with default values from
   the DDL for the table used in the query so those values are
   immediately available for ResultSet accessors? This
   functionality requires a call to the database for metadata
   each time a result set of this type is created. If disabled
   (the default), the default values will be populated by the an
   internal call to refreshRow() which pulls back default values
   and/or values changed by triggers.

   Default: false

   Since version: 5.0.5

   processEscapeCodesForPrepStmts

   Should the driver process escape codes in queries that are
   prepared? Default escape processing behavior in non-prepared
   statements must be defined with the property
   'enableEscapeProcessing'.

   Default: true

   Since version: 3.1.12

   queryTimeoutKillsConnection

   If the timeout given in Statement.setQueryTimeout() expires,
   should the driver forcibly abort the Connection instead of
   attempting to abort the query?

   Default: false

   Since version: 5.1.9

   relaxAutoCommit

   If the version of MySQL the driver connects to does not
   support transactions, still allow calls to commit(),
   rollback() and setAutoCommit() (true/false, defaults to
   'false')?

   Default: false

   Since version: 2.0.13

   retainStatementAfterResultSetClose

   Should the driver retain the Statement reference in a
   ResultSet after ResultSet.close() has been called. This is
   not JDBC-compliant after JDBC-4.0.

   Default: false

   Since version: 3.1.11

   rollbackOnPooledClose

   Should the driver issue a rollback() when the logical
   connection in a pool is closed?

   Default: true

   Since version: 3.0.15

   runningCTS13

   Enables workarounds for bugs in Sun's JDBC compliance
   testsuite version 1.3

   Default: false

   Since version: 3.1.7

   sendFractionalSeconds

   Send fractional part from TIMESTAMP seconds. If set to false,
   the nanoseconds value of TIMESTAMP values will be truncated
   before sending any data to the server. This option applies
   only to prepared statements, callable statements or updatable
   result sets.

   Default: true

   Since version: 5.1.37

   serverTimezone

   Override detection/mapping of time zone. Used when time zone
   from server doesn't map to Java time zone

   Since version: 3.0.2

   statementInterceptors

   A comma-delimited list of classes that implement
   "com.mysql.jdbc.StatementInterceptor" that should be placed
   "in between" query execution to influence the results.
   StatementInterceptors are "chainable", the results returned
   by the "current" interceptor will be passed on to the next in
   in the chain, from left-to-right order, as specified in this
   property.

   Since version: 5.1.1

   strictFloatingPoint

   Used only in older versions of compliance test

   Default: false

   Since version: 3.0.0

   strictUpdates

   Should the driver do strict checking (all primary keys
   selected) of updatable result sets (true, false, defaults to
   'true')?

   Default: true

   Since version: 3.0.4

   tinyInt1isBit

   Should the driver treat the datatype TINYINT(1) as the BIT
   type (because the server silently converts BIT -> TINYINT(1)
   when creating tables)?

   Default: true

   Since version: 3.0.16

   transformedBitIsBoolean

   If the driver converts TINYINT(1) to a different type, should
   it use BOOLEAN instead of BIT for future compatibility with
   MySQL-5.0, as MySQL-5.0 has a BIT type?

   Default: false

   Since version: 3.1.9

   treatUtilDateAsTimestamp

   Should the driver treat java.util.Date as a TIMESTAMP for the
   purposes of PreparedStatement.setObject()?

   Default: true

   Since version: 5.0.5

   ultraDevHack

   Create PreparedStatements for prepareCall() when required,
   because UltraDev is broken and issues a prepareCall() for
   _all_ statements? (true/false, defaults to 'false')

   Default: false

   Since version: 2.0.3

   useAffectedRows

   Don't set the CLIENT_FOUND_ROWS flag when connecting to the
   server (not JDBC-compliant, will break most applications that
   rely on "found" rows vs. "affected rows" for DML statements),
   but does cause "correct" update counts from "INSERT ... ON
   DUPLICATE KEY UPDATE" statements to be returned by the
   server.

   Default: false

   Since version: 5.1.7

   useGmtMillisForDatetimes

   Convert between session time zone and GMT before creating
   Date and Timestamp instances (value of 'false' leads to
   legacy behavior, 'true' leads to more JDBC-compliant
   behavior)? This is part of the legacy date-time code, thus
   the property has an effect only when
   "useLegacyDatetimeCode=true."

   Default: false

   Since version: 3.1.12

   useHostsInPrivileges

   Add '@hostname' to users in
   DatabaseMetaData.getColumn/TablePrivileges() (true/false),
   defaults to 'true'.

   Default: true

   Since version: 3.0.2

   useInformationSchema

   When connected to MySQL-5.0.7 or newer, should the driver use
   the INFORMATION_SCHEMA to derive information used by
   DatabaseMetaData?

   Default: false

   Since version: 5.0.0

   useJDBCCompliantTimezoneShift

   Should the driver use JDBC-compliant rules when converting
   TIME/TIMESTAMP/DATETIME values' time zone information for
   those JDBC arguments which take a java.util.Calendar
   argument? This is part of the legacy date-time code, thus the
   property has an effect only when
   "useLegacyDatetimeCode=true."

   Default: false

   Since version: 5.0.0

   useLegacyDatetimeCode

   Use code for DATE/TIME/DATETIME/TIMESTAMP handling in result
   sets and statements that consistently handles time zone
   conversions from client to server and back again, or use the
   legacy code for these datatypes that has been in the driver
   for backwards-compatibility? Setting this property to 'false'
   voids the effects of "useTimezone,"
   "useJDBCCompliantTimezoneShift," "useGmtMillisForDatetimes,"
   and "useFastDateParsing."

   Default: true

   Since version: 5.1.6

   useOldAliasMetadataBehavior

   Should the driver use the legacy behavior for "AS" clauses on
   columns and tables, and only return aliases (if any) for
   ResultSetMetaData.getColumnName() or
   ResultSetMetaData.getTableName() rather than the original
   column/table name? In 5.0.x, the default value was true.

   Default: false

   Since version: 5.0.4

   useOldUTF8Behavior

   Use the UTF-8 behavior the driver did when communicating with
   4.0 and older servers

   Default: false

   Since version: 3.1.6

   useOnlyServerErrorMessages

   Don't prepend 'standard' SQLState error messages to error
   messages returned by the server.

   Default: true

   Since version: 3.0.15

   useSSPSCompatibleTimezoneShift

   If migrating from an environment that was using server-side
   prepared statements, and the configuration property
   "useJDBCCompliantTimeZoneShift" set to "true", use compatible
   behavior when not using server-side prepared statements when
   sending TIMESTAMP values to the MySQL server.

   Default: false

   Since version: 5.0.5

   useServerPrepStmts

   Use server-side prepared statements if the server supports
   them?

   Default: false

   Since version: 3.1.0

   useSqlStateCodes

   Use SQL Standard state codes instead of 'legacy' X/Open/SQL
   state codes (true/false), default is 'true'

   Default: true

   Since version: 3.1.3

   useStreamLengthsInPrepStmts

   Honor stream length parameter in
   PreparedStatement/ResultSet.setXXXStream() method calls
   (true/false, defaults to 'true')?

   Default: true

   Since version: 3.0.2

   useTimezone

   Convert time/date types between client and server time zones
   (true/false, defaults to 'false')? This is part of the legacy
   date-time code, thus the property has an effect only when
   "useLegacyDatetimeCode=true."

   Default: false

   Since version: 3.0.2

   useUnbufferedInput

   Don't use BufferedInputStream for reading data from the
   server

   Default: true

   Since version: 3.0.11

   yearIsDateType

   Should the JDBC driver treat the MySQL type "YEAR" as a
   java.sql.Date, or as a SHORT?

   Default: true

   Since version: 3.1.9

   zeroDateTimeBehavior

   What should happen when the driver encounters DATETIME values
   that are composed entirely of zeros (used by MySQL to
   represent invalid dates)? Valid values are "exception",
   "round" and "convertToNull".

   Default: exception

   Since version: 3.1.4

   Connector/J also supports access to MySQL using named pipes
   on Windows platforms with the NamedPipeSocketFactory as a
   plugin-socket factory. If you do not use a namedPipePath
   property, the default of '\\.\pipe\MySQL' is used. If you use
   the NamedPipeSocketFactory, the host name and port number
   values in the JDBC URL are ignored. To enable this feature,
   set the socketFactory property:
socketFactory=com.mysql.jdbc.NamedPipeSocketFactory

   Named pipes only work when connecting to a MySQL server on
   the same physical machine where the JDBC driver is running.
   In simple performance tests, named pipe access is between
   30%-50% faster than the standard TCP/IP access. However, this
   varies per system, and named pipes are slower than TCP/IP in
   many Windows configurations.

   To create your own socket factories, follow the example code
   in com.mysql.jdbc.NamedPipeSocketFactory, or
   com.mysql.jdbc.StandardSocketFactory.

5.1.1 Properties Files for the useConfigs Option

   The useConfigs connection option is convenient shorthand for
   specifying combinations of options for particular scenarios.
   The argument values you can use with this option correspond
   to the names of .properties files within the Connector/J
   mysql-connector-java-version-bin.jar JAR file. For example,
   the Connector/J 5.1.9 driver includes the following
   configuration properties files:
$ unzip mysql-connector-java-5.1.19-bin.jar '*/configs/*'
Archive:  mysql-connector-java-5.1.19-bin.jar
   creating: com/mysql/jdbc/configs/
  inflating: com/mysql/jdbc/configs/3-0-Compat.properties
  inflating: com/mysql/jdbc/configs/5-0-Compat.properties
  inflating: com/mysql/jdbc/configs/clusterBase.properties
  inflating: com/mysql/jdbc/configs/coldFusion.properties
  inflating: com/mysql/jdbc/configs/fullDebug.properties
  inflating: com/mysql/jdbc/configs/maxPerformance.properties
  inflating: com/mysql/jdbc/configs/solarisMaxPerformance.properties

   To specify one of these combinations of options, specify
   useConfigs=3-0-Compat, useConfigs=maxPerformance, and so on.
   The following sections show the options that are part of each
   useConfigs setting. For the details of why each one is
   included, see the comments in the .properties files.

3-0-Compat

emptyStringsConvertToZero=true
jdbcCompliantTruncation=false
noDatetimeStringSync=true
nullCatalogMeansCurrent=true
nullNamePatternMatchesAll=true
transformedBitIsBoolean=false
dontTrackOpenResources=true
zeroDateTimeBehavior=convertToNull
useServerPrepStmts=false
autoClosePStmtStreams=true
processEscapeCodesForPrepStmts=false
useFastDateParsing=false
populateInsertRowWithDefaultValues=false
useDirectRowUnpack=false

5-0-Compat

useDirectRowUnpack=false

clusterBase

autoReconnect=true
failOverReadOnly=false
roundRobinLoadBalance=true

coldFusion

useDynamicCharsetInfo=false
alwaysSendSetIsolation=false
useLocalSessionState=true
autoReconnect=true

fullDebug

profileSQL=true
gatherPerfMetrics=true
useUsageAdvisor=true
logSlowQueries=true
explainSlowQueries=true

maxPerformance

cachePrepStmts=true
cacheCallableStmts=true
cacheServerConfiguration=true
useLocalSessionState=true
elideSetAutoCommits=true
alwaysSendSetIsolation=false
enableQueryTimeouts=false

solarisMaxPerformance

useUnbufferedInput=false
useReadAheadInput=false
maintainTimeStats=false

5.2 JDBC API Implementation Notes

   MySQL Connector/J, as a rigorous implementation of the JDBC
   API
   (http://www.oracle.com/technetwork/java/javase/jdbc/index.htm
   l), passes all of the tests in the publicly available version
   of Oracle's JDBC compliance test suite. The JDBC
   specification is flexible on how certain functionality should
   be implemented. This section gives details on an
   interface-by-interface level about implementation decisions
   that might affect how you code applications with MySQL
   Connector/J.

     * BLOB
       Starting with Connector/J version 3.1.0, you can emulate
       BLOBs with locators by adding the property
       emulateLocators=true to your JDBC URL. Using this method,
       the driver will delay loading the actual BLOB data until
       you retrieve the other data and then use retrieval
       methods (getInputStream(), getBytes(), and so forth) on
       the BLOB data stream.
       You must use a column alias with the value of the column
       to the actual name of the BLOB, for example:
SELECT id, 'data' as blob_data from blobtable

       You must also follow these rules:

          + The SELECT
            (http://dev.mysql.com/doc/refman/5.7/en/select.html)
            must reference only one table. The table must have a
            primary key
            (http://dev.mysql.com/doc/refman/5.7/en/glossary.htm
            l#glos_primary_key).

          + The SELECT
            (http://dev.mysql.com/doc/refman/5.7/en/select.html)
            must alias the original BLOB column name, specified
            as a string, to an alternate name.

          + The SELECT
            (http://dev.mysql.com/doc/refman/5.7/en/select.html)
            must cover all columns that make up the primary key.
       The BLOB implementation does not allow in-place
       modification (they are copies, as reported by the
       DatabaseMetaData.locatorsUpdateCopies() method). Because
       of this, use the corresponding
       PreparedStatement.setBlob() or ResultSet.updateBlob() (in
       the case of updatable result sets) methods to save
       changes back to the database.

     * CallableStatement
       Starting with Connector/J 3.1.1, stored procedures are
       supported when connecting to MySQL version 5.0 or newer
       using the CallableStatement interface. Currently, the
       getParameterMetaData() method of CallableStatement is not
       supported.

     * CLOB
       The CLOB implementation does not allow in-place
       modification (they are copies, as reported by the
       DatabaseMetaData.locatorsUpdateCopies() method). Because
       of this, use the PreparedStatement.setClob() method to
       save changes back to the database. The JDBC API does not
       have a ResultSet.updateClob() method.

     * Connection
       Unlike the pre-Connector/J JDBC driver (MM.MySQL), the
       isClosed() method does not ping the server to determine
       if it is available. In accordance with the JDBC
       specification, it only returns true if closed() has been
       called on the connection. If you need to determine if the
       connection is still valid, issue a simple query, such as
       SELECT 1. The driver will throw an exception if the
       connection is no longer valid.

     * DatabaseMetaData
       Foreign key
       (http://dev.mysql.com/doc/refman/5.7/en/glossary.html#glo
       s_foreign_key) information
       (getImportedKeys()/getExportedKeys() and
       getCrossReference()) is only available from InnoDB
       (http://dev.mysql.com/doc/refman/5.7/en/innodb-storage-en
       gine.html) tables. The driver uses SHOW CREATE TABLE
       (http://dev.mysql.com/doc/refman/5.7/en/show-create-table
       .html) to retrieve this information, so if any other
       storage engines add support for foreign keys, the driver
       would transparently support them as well.

     * PreparedStatement
       PreparedStatements are implemented by the driver, as
       MySQL does not have a prepared statement feature. Because
       of this, the driver does not implement
       getParameterMetaData() or getMetaData() as it would
       require the driver to have a complete SQL parser in the
       client.
       Starting with version 3.1.0 MySQL Connector/J,
       server-side prepared statements and binary-encoded result
       sets are used when the server supports them.
       Take care when using a server-side prepared statement
       with large parameters that are set using
       setBinaryStream(), setAsciiStream(), setUnicodeStream(),
       setBlob(), or setClob(). To re-execute the statement with
       any large parameter changed to a nonlarge parameter, call
       clearParameters() and set all parameters again. The
       reason for this is as follows:

          + During both server-side prepared statements and
            client-side emulation, large data is exchanged only
            when PreparedStatement.execute() is called.

          + Once that has been done, the stream used to read the
            data on the client side is closed (as per the JDBC
            spec), and cannot be read from again.

          + If a parameter changes from large to nonlarge, the
            driver must reset the server-side state of the
            prepared statement to allow the parameter that is
            being changed to take the place of the prior large
            value. This removes all of the large data that has
            already been sent to the server, thus requiring the
            data to be re-sent, using the setBinaryStream(),
            setAsciiStream(), setUnicodeStream(), setBlob() or
            setClob() method.
       Consequently, to change the type of a parameter to a
       nonlarge one, you must call clearParameters() and set all
       parameters of the prepared statement again before it can
       be re-executed.

     * ResultSet
       By default, ResultSets are completely retrieved and
       stored in memory. In most cases this is the most
       efficient way to operate and, due to the design of the
       MySQL network protocol, is easier to implement. If you
       are working with ResultSets that have a large number of
       rows or large values and cannot allocate heap space in
       your JVM for the memory required, you can tell the driver
       to stream the results back one row at a time.
       To enable this functionality, create a Statement instance
       in the following manner:
stmt = conn.createStatement(java.sql.ResultSet.TYPE_FORWARD_ONLY,
              java.sql.ResultSet.CONCUR_READ_ONLY);
stmt.setFetchSize(Integer.MIN_VALUE);

       The combination of a forward-only, read-only result set,
       with a fetch size of Integer.MIN_VALUE serves as a signal
       to the driver to stream result sets row-by-row. After
       this, any result sets created with the statement will be
       retrieved row-by-row.
       There are some caveats with this approach. You must read
       all of the rows in the result set (or close it) before
       you can issue any other queries on the connection, or an
       exception will be thrown.
       The earliest the locks these statements hold can be
       released (whether they be MyISAM table-level locks or
       row-level locks in some other storage engine such as
       InnoDB) is when the statement completes.
       If the statement is within scope of a transaction, then
       locks are released when the transaction completes (which
       implies that the statement needs to complete first). As
       with most other databases, statements are not complete
       until all the results pending on the statement are read
       or the active result set for the statement is closed.
       Therefore, if using streaming results, process them as
       quickly as possible if you want to maintain concurrent
       access to the tables referenced by the statement
       producing the result set.

     * ResultSetMetaData
       The isAutoIncrement() method only works when using MySQL
       servers 4.0 and newer.

     * Statement
       When using versions of the JDBC driver earlier than
       3.2.1, and connected to server versions earlier than
       5.0.3, the setFetchSize() method has no effect, other
       than to toggle result set streaming as described above.
       Connector/J 5.0.0 and later include support for both
       Statement.cancel() and Statement.setQueryTimeout(). Both
       require MySQL 5.0.0 or newer server, and require a
       separate connection to issue the KILL QUERY
       (http://dev.mysql.com/doc/refman/5.7/en/kill.html)
       statement. In the case of setQueryTimeout(), the
       implementation creates an additional thread to handle the
       timeout functionality.
       Note
       Failures to cancel the statement for setQueryTimeout()
       may manifest themselves as RuntimeException rather than
       failing silently, as there is currently no way to unblock
       the thread that is executing the query being cancelled
       due to timeout expiration and have it throw the exception
       instead.
       Note
       The MySQL statement KILL QUERY
       (http://dev.mysql.com/doc/refman/5.7/en/kill.html) (which
       is what the driver uses to implement Statement.cancel())
       is non-deterministic; thus, avoid the use of
       Statement.cancel() if possible. If no query is in
       process, the next query issued will be killed by the
       server. This race condition is guarded against as of
       Connector/J 5.1.18.
       MySQL does not support SQL cursors, and the JDBC driver
       doesn't emulate them, so setCursorName() has no effect.
       Connector/J 5.1.3 and later include two additional
       methods:

          + setLocalInfileInputStream() sets an InputStream
            instance that will be used to send data to the MySQL
            server for a LOAD DATA LOCAL INFILE
            (http://dev.mysql.com/doc/refman/5.7/en/load-data.ht
            ml) statement rather than a FileInputStream or
            URLInputStream that represents the path given as an
            argument to the statement.
            This stream will be read to completion upon
            execution of a LOAD DATA LOCAL INFILE
            (http://dev.mysql.com/doc/refman/5.7/en/load-data.ht
            ml) statement, and will automatically be closed by
            the driver, so it needs to be reset before each call
            to execute*() that would cause the MySQL server to
            request data to fulfill the request for LOAD DATA
            LOCAL INFILE
            (http://dev.mysql.com/doc/refman/5.7/en/load-data.ht
            ml).
            If this value is set to NULL, the driver will revert
            to using a FileInputStream or URLInputStream as
            required.

          + getLocalInfileInputStream() returns the InputStream
            instance that will be used to send data in response
            to a LOAD DATA LOCAL INFILE
            (http://dev.mysql.com/doc/refman/5.7/en/load-data.ht
            ml) statement.
            This method returns NULL if no such stream has been
            set using setLocalInfileInputStream().

5.3 Java, JDBC and MySQL Types

   MySQL Connector/J is flexible in the way it handles
   conversions between MySQL data types and Java data types.

   In general, any MySQL data type can be converted to a
   java.lang.String, and any numeric type can be converted to
   any of the Java numeric types, although round-off, overflow,
   or loss of precision may occur.
   Note

   All TEXT types return Types.LONGVARCHAR with different
   getPrecision() values (65535, 255, 16777215, and 2147483647
   respectively) with getColumnType() returning -1. This
   behavior is intentional even though TINYTEXT does not fall,
   regarding to its size, within the LONGVARCHAR category. This
   is to avoid different handling inside the same base type. And
   getColumnType() returns -1 because the internal server
   handling is of type TEXT, which is similar to BLOB.

   Also note that getColumnTypeName() will return VARCHAR even
   though getColumnType() returns Types.LONGVARCHAR, because
   VARCHAR is the designated column database-specific name for
   this type.

   Starting with Connector/J 3.1.0, the JDBC driver issues
   warnings or throws DataTruncation exceptions as is required
   by the JDBC specification unless the connection was
   configured not to do so by using the property
   jdbcCompliantTruncation and setting it to false.

   The conversions that are always guaranteed to work are listed
   in the following table. The first column lists one or more
   MySQL data types, and the second column lists one or more
   Java types to which the MySQL types can be converted.

   Table 5.1 Connection Properties - Miscellaneous
   These MySQL Data Types Can always be converted to these Java
   types
   CHAR, VARCHAR, BLOB, TEXT, ENUM, and SET java.lang.String,
   java.io.InputStream, java.io.Reader, java.sql.Blob,
   java.sql.Clob
   FLOAT, REAL, DOUBLE PRECISION, NUMERIC, DECIMAL, TINYINT,
   SMALLINT, MEDIUMINT, INTEGER, BIGINT java.lang.String,
   java.lang.Short, java.lang.Integer, java.lang.Long,
   java.lang.Double, java.math.BigDecimal
   DATE, TIME, DATETIME, TIMESTAMP java.lang.String,
   java.sql.Date, java.sql.Timestamp
   Note

   Round-off, overflow or loss of precision may occur if you
   choose a Java numeric data type that has less precision or
   capacity than the MySQL data type you are converting to/from.

   The ResultSet.getObject() method uses the type conversions
   between MySQL and Java types, following the JDBC
   specification where appropriate. The value returned by
   ResultSetMetaData.GetColumnClassName() is also shown below.
   For more information on the JDBC types, see the reference on
   the java.sql.Types
   (http://docs.oracle.com/javase/8/docs/api/java/sql/Types.html
   ) class.

   Table 5.2 MySQL Types to Java Types for ResultSet.getObject()
   MySQL Type Name Return value of GetColumnClassName Returned
   as Java Class
   BIT(1) (new in MySQL-5.0) BIT java.lang.Boolean
   BIT( > 1) (new in MySQL-5.0) BIT byte[]
   TINYINT TINYINT java.lang.Boolean if the configuration
   property tinyInt1isBit is set to true (the default) and the
   storage size is 1, or java.lang.Integer if not.
   BOOL, BOOLEAN TINYINT See TINYINT, above as these are aliases
   for TINYINT(1), currently.
   SMALLINT[(M)] [UNSIGNED] SMALLINT [UNSIGNED]
   java.lang.Integer (regardless if UNSIGNED or not)
   MEDIUMINT[(M)] [UNSIGNED] MEDIUMINT [UNSIGNED]
   java.lang.Integer, if UNSIGNED java.lang.Long (C/J 3.1 and
   earlier), or java.lang.Integer for C/J 5.0 and later
   INT,INTEGER[(M)] [UNSIGNED] INTEGER [UNSIGNED]
   java.lang.Integer, if UNSIGNED java.lang.Long
   BIGINT[(M)] [UNSIGNED] BIGINT [UNSIGNED] java.lang.Long, if
   UNSIGNED java.math.BigInteger
   FLOAT[(M,D)] FLOAT java.lang.Float
   DOUBLE[(M,B)] DOUBLE java.lang.Double
   DECIMAL[(M[,D])] DECIMAL java.math.BigDecimal
   DATE DATE java.sql.Date
   DATETIME DATETIME java.sql.Timestamp
   TIMESTAMP[(M)] TIMESTAMP java.sql.Timestamp
   TIME TIME java.sql.Time
   YEAR[(2|4)] YEAR If yearIsDateType configuration property is
   set to false, then the returned object type is
   java.sql.Short. If set to true (the default), then the
   returned object is of type java.sql.Date with the date set to
   January 1st, at midnight.
   CHAR(M) CHAR java.lang.String (unless the character set for
   the column is BINARY, then byte[] is returned.
   VARCHAR(M) [BINARY] VARCHAR java.lang.String (unless the
   character set for the column is BINARY, then byte[] is
   returned.
   BINARY(M) BINARY byte[]
   VARBINARY(M) VARBINARY byte[]
   TINYBLOB TINYBLOB byte[]
   TINYTEXT VARCHAR java.lang.String
   BLOB BLOB byte[]
   TEXT VARCHAR java.lang.String
   MEDIUMBLOB MEDIUMBLOB byte[]
   MEDIUMTEXT VARCHAR java.lang.String
   LONGBLOB LONGBLOB byte[]
   LONGTEXT VARCHAR java.lang.String
   ENUM('value1','value2',...) CHAR java.lang.String
   SET('value1','value2',...) CHAR java.lang.String

5.4 Using Character Sets and Unicode

   All strings sent from the JDBC driver to the server are
   converted automatically from native Java Unicode form to the
   client character encoding, including all queries sent using
   Statement.execute(), Statement.executeUpdate(),
   Statement.executeQuery() as well as all PreparedStatement and
   CallableStatement parameters with the exclusion of parameters
   set using setBytes(), setBinaryStream(), setAsciiStream(),
   setUnicodeStream() and setBlob().

Number of Encodings Per Connection

   In MySQL Server 4.1 and higher, Connector/J supports a single
   character encoding between client and server, and any number
   of character encodings for data returned by the server to the
   client in ResultSets.

   Prior to MySQL Server 4.1, Connector/J supported a single
   character encoding per connection, which could either be
   automatically detected from the server configuration, or
   could be configured by the user through the useUnicode and
   characterEncoding properties.

Setting the Character Encoding

   The character encoding between client and server is
   automatically detected upon connection. You specify the
   encoding on the server using the character_set_server
   (http://dev.mysql.com/doc/refman/5.7/en/server-system-variabl
   es.html#sysvar_character_set_server) for server versions
   4.1.0 and newer, and character_set system variable for server
   versions older than 4.1.0. The driver automatically uses the
   encoding specified by the server. For more information, see
   Server Character Set and Collation
   (http://dev.mysql.com/doc/refman/5.7/en/charset-server.html).

   For example, to use 4-byte UTF-8 character sets with
   Connector/J, configure the MySQL server with
   character_set_server=utf8mb4
   (http://dev.mysql.com/doc/refman/5.7/en/server-system-variabl
   es.html#sysvar_character_set_server), and leave
   characterEncoding out of the Connector/J connection string.
   Connector/J will then autodetect the UTF-8 setting.

   To override the automatically detected encoding on the client
   side, use the characterEncoding property in the URL used to
   connect to the server.

   To allow multiple character sets to be sent from the client,
   use the UTF-8 encoding, either by configuring utf8 as the
   default server character set, or by configuring the JDBC
   driver to use UTF-8 through the characterEncoding property.

   When specifying character encodings on the client side, use
   Java-style names. The following table lists MySQL character
   set names and the corresponding Java-style names:

   Table 5.3 MySQL to Java Encoding Name Translations
   MySQL Character Set Name Java-Style Character Encoding Name
   ascii US-ASCII
   big5 Big5
   gbk GBK
   sjis SJIS (or Cp932 or MS932 for MySQL Server < 4.1.11)
   cp932 Cp932 or MS932 (MySQL Server > 4.1.11)
   gb2312 EUC_CN
   ujis EUC_JP
   euckr EUC_KR
   latin1 Cp1252
   latin2 ISO8859_2
   greek ISO8859_7
   hebrew ISO8859_8
   cp866 Cp866
   tis620 TIS620
   cp1250 Cp1250
   cp1251 Cp1251
   cp1257 Cp1257
   macroman MacRoman
   macce MacCentralEurope
   utf8 UTF-8
   ucs2 UnicodeBig
   Warning

   Do not issue the query set names with Connector/J, as the
   driver will not detect that the character set has changed,
   and will continue to use the character set detected during
   the initial connection setup.

5.5 Connecting Securely Using SSL

   SSL in MySQL Connector/J encrypts all data (other than the
   initial handshake) between the JDBC driver and the server.
   There is a performance penalty for enabling SSL, the severity
   of which depends on multiple factors including (but not
   limited to) the size of the query, the amount of data
   returned, the server hardware, the SSL library used, the
   network bandwidth, and so on.

   For SSL support to work, you must have the following:

     * A JDK that includes JSSE (Java Secure Sockets Extension),
       like JDK-1.4.1 or newer. SSL does not currently work with
       a JDK that you can add JSSE to, like JDK-1.2.x or
       JDK-1.3.x due to the following JSSE bug:
       http://bugs.java.com/bugdatabase/view_bug.do?bug_id=42735
       44

     * A MySQL server that supports SSL and has been compiled
       and configured to do so, which is MySQL 4.0.4 or later.
       For more information, see Building MySQL with Support for
       Secure Connections
       (http://dev.mysql.com/doc/refman/5.7/en/building-with-sec
       ure-connection-support.html).

     * A client certificate (covered later in this section)

   The system works through two Java truststore files, one file
   contains the certificate information for the server
   (truststore in the examples below). The other file contains
   the certificate for the client (keystore in the examples
   below). All Java truststore files are password protected by
   supplying a suitable password to the keytool when you create
   the files. You need the file names and associated passwords
   to create an SSL connection.

   You will first need to import the MySQL server CA Certificate
   into a Java truststore. A sample MySQL server CA Certificate
   is located in the SSL subdirectory of the MySQL source
   distribution. This is what SSL will use to determine if you
   are communicating with a secure MySQL server. Alternatively,
   use the CA Certificate that you have generated or been
   provided with by your SSL provider.

   To use Java's keytool to create a truststore in the current
   directory , and import the server's CA certificate
   (cacert.pem), you can do the following (assuming that keytool
   is in your path. The keytool is typically located in the bin
   subdirectory of your JDK or JRE):
shell> keytool -import -alias mysqlServerCACert \
         -file cacert.pem -keystore truststore

   Enter the password when prompted for the keystore file.
   Interaction with keytool looks like this:
Enter keystore password:  *********
Owner: EMAILADDRESS=walrus@example.com, CN=Walrus,
       O=My Company, L=Orenburg, ST=Some-State, C=RU
Issuer: EMAILADDRESS=walrus@example.com, CN=Walrus,
       O=My Company, L=Orenburg, ST=Some-State, C=RU
Serial number: 0
Valid from:
   Fri Aug 02 16:55:53 CDT 2002 until: Sat Aug 02 16:55:53 CDT 2003
Certificate fingerprints:
    MD5:  61:91:A0:F2:03:07:61:7A:81:38:66:DA:19:C4:8D:AB
    SHA1: 25:77:41:05:D5:AD:99:8C:14:8C:CA:68:9C:2F:B8:89:C3:34:4D:6C
Trust this certificate? [no]:  yes
Certificate was added to keystore

   You then have two options: either import the client
   certificate that matches the CA certificate you just
   imported, or create a new client certificate.

   Importing an existing certificate requires the certificate to
   be in DER format. You can use openssl to convert an existing
   certificate into the new format. For example:
shell> openssl x509 -outform DER -in client-cert.pem -out client.cert

   Now import the converted certificate into your keystore using
   keytool:
shell> keytool -import -file client.cert -keystore keystore -alias mys
qlClientCertificate

   To generate your own client certificate, use keytool to
   create a suitable certificate and add it to the keystore
   file:
shell> keytool -genkey -keyalg rsa \
     -alias mysqlClientCertificate -keystore keystore

   Keytool will prompt you for the following information, and
   create a keystore named keystore in the current directory.

   Respond with information that is appropriate for your
   situation:
Enter keystore password:  *********
What is your first and last name?
  [Unknown]:  Matthews
What is the name of your organizational unit?
  [Unknown]:  Software Development
What is the name of your organization?
  [Unknown]:  My Company
What is the name of your City or Locality?
  [Unknown]:  Flossmoor
What is the name of your State or Province?
  [Unknown]:  IL
What is the two-letter country code for this unit?
  [Unknown]:  US
Is <CN=Matthews, OU=Software Development, O=My Company,
 L=Flossmoor, ST=IL, C=US> correct?
  [no]:  y

Enter key password for <mysqlClientCertificate>
        (RETURN if same as keystore password):

   Finally, to get JSSE to use the keystore and truststore that
   you have generated, you need to set the following system
   properties when you start your JVM, replacing
   path_to_keystore_file with the full path to the keystore file
   you created, path_to_truststore_file with the path to the
   truststore file you created, and using the appropriate
   password values for each property. You can do this either on
   the command line:
-Djavax.net.ssl.keyStore=path_to_keystore_file
-Djavax.net.ssl.keyStorePassword=password
-Djavax.net.ssl.trustStore=path_to_truststore_file
-Djavax.net.ssl.trustStorePassword=password

   Or you can set the values directly within the application:
System.setProperty("javax.net.ssl.keyStore","path_to_keystore_file");
System.setProperty("javax.net.ssl.keyStorePassword","password");
System.setProperty("javax.net.ssl.trustStore","path_to_truststore_file
");
System.setProperty("javax.net.ssl.trustStorePassword","password");

   You will also need to set useSSL to true in your connection
   parameters for MySQL Connector/J, either by adding
   useSSL=true to your URL, or by setting the property useSSL to
   true in the java.util.Properties instance you pass to
   DriverManager.getConnection().

   You can test that SSL is working by turning on JSSE debugging
   (as detailed below), and look for the following key events:
...
*** ClientHello, v3.1
RandomCookie:  GMT: 1018531834 bytes = { 199, 148, 180, 215, 74, 12,
??
  54, 244, 0, 168, 55, 103, 215, 64, 16, 138, 225, 190, 132, 153, 2,
??
  217, 219, 239, 202, 19, 121, 78 }
Session ID:  {}
Cipher Suites:  { 0, 5, 0, 4, 0, 9, 0, 10, 0, 18, 0, 19, 0, 3, 0, 17 }
Compression Methods:  { 0 }
***
[write] MD5 and SHA1 hashes:  len = 59
0000: 01 00 00 37 03 01 3D B6 90 FA C7 94 B4 D7 4A 0C  ...7..=.......J
.
0010: 36 F4 00 A8 37 67 D7 40 10 8A E1 BE 84 99 02 D9  6...7g.@.......
.
0020: DB EF CA 13 79 4E 00 00 10 00 05 00 04 00 09 00  ....yN.........
.
0030: 0A 00 12 00 13 00 03 00 11 01 00                 ...........
main, WRITE:  SSL v3.1 Handshake, length = 59
main, READ:  SSL v3.1 Handshake, length = 74
*** ServerHello, v3.1
RandomCookie:  GMT: 1018577560 bytes = { 116, 50, 4, 103, 25, 100, 58,
 ??
   202, 79, 185, 178, 100, 215, 66, 254, 21, 83, 187, 190, 42, 170, 3,
 ??
   132, 110, 82, 148, 160, 92 }
Session ID:  {163, 227, 84, 53, 81, 127, 252, 254, 178, 179, 68, 63,
??
   182, 158, 30, 11, 150, 79, 170, 76, 255, 92, 15, 226, 24, 17, 177,
??
   219, 158, 177, 187, 143}
Cipher Suite:  { 0, 5 }
Compression Method: 0
***
%% Created:  [Session-1, SSL_RSA_WITH_RC4_128_SHA]
** SSL_RSA_WITH_RC4_128_SHA
[read] MD5 and SHA1 hashes:  len = 74
0000: 02 00 00 46 03 01 3D B6 43 98 74 32 04 67 19 64  ...F..=.C.t2.g.
d
0010: 3A CA 4F B9 B2 64 D7 42 FE 15 53 BB BE 2A AA 03  :.O..d.B..S..*.
.
0020: 84 6E 52 94 A0 5C 20 A3 E3 54 35 51 7F FC FE B2  .nR..\ ..T5Q...
.
0030: B3 44 3F B6 9E 1E 0B 96 4F AA 4C FF 5C 0F E2 18  .D?.....O.L.\..
.
0040: 11 B1 DB 9E B1 BB 8F 00 05 00                    ..........
main, READ:  SSL v3.1 Handshake, length = 1712
...

   JSSE provides debugging (to stdout) when you set the
   following system property: -Djavax.net.debug=all This will
   tell you what keystores and truststores are being used, as
   well as what is going on during the SSL handshake and
   certificate exchange. It will be helpful when trying to
   determine what is not working when trying to get an SSL
   connection to happen.

5.6 Connecting Using PAM Authentication

   Java applications using Connector/J 5.1.21 and higher can
   connect to MySQL servers that use the pluggable
   authentication module (PAM) authentication scheme.

   For PAM authentication to work, you must have the following:

     * A MySQL server that supports PAM authentication: a
       commercial distribution of MySQL 5.5.16 or higher. See
       The PAM Authentication Plugin
       (http://dev.mysql.com/doc/refman/5.7/en/pam-authenticatio
       n-plugin.html) for more information. Connector/J
       implements the same cleartext authentication method as in
       The Cleartext Client-Side Authentication Plugin
       (http://dev.mysql.com/doc/refman/5.7/en/cleartext-authent
       ication-plugin.html).

     * SSL capability, as explained in Section 5.5, "Connecting
       Securely Using SSL." Because the PAM authentication
       scheme sends the original password to the server, the
       connection to the server must be encrypted.

   PAM authentication support is enabled by default in
   Connector/J 5.1.21 and up, so no extra configuration is
   needed.

   To disable the PAM authentication feature, specify
   mysql_clear_password (the method) or
   com.mysql.jdbc.authentication.MysqlClearPasswordPlugin (the
   class name) in the comma-separated list of arguments for the
   disabledAuthenticationPlugins connection option. See Section
   5.1, "Driver/Datasource Class Names, URL Syntax and
   Configuration Properties for Connector/J" for details about
   that connection option.

5.7 Using Master/Slave Replication with ReplicationConnection

   See Section 8.3, "Configuring Master/Slave Replication with
   Connector/J" for details on the topic.

5.8 Mapping MySQL Error Numbers to JDBC SQLState Codes

   The table below provides a mapping of the MySQL error numbers
   to JDBC SQLState values.

   Table 5.4 Mapping of MySQL Error Numbers to SQLStates
   MySQL Error Number MySQL Error Name Legacy (X/Open) SQLState
   SQL Standard SQLState
   1022 ER_DUP_KEY 23000 23000
   1037 ER_OUTOFMEMORY S1001 HY001
   1038 ER_OUT_OF_SORTMEMORY S1001 HY001
   1040 ER_CON_COUNT_ERROR 08004 08004
   1042 ER_BAD_HOST_ERROR 08004 08S01
   1043 ER_HANDSHAKE_ERROR 08004 08S01
   1044 ER_DBACCESS_DENIED_ERROR 42000 42000
   1045 ER_ACCESS_DENIED_ERROR 28000 28000
   1046 ER_NO_DB_ERROR 3D000 3D000
   1047 ER_UNKNOWN_COM_ERROR 08S01 08S01
   1048 ER_BAD_NULL_ERROR 23000 23000
   1049 ER_BAD_DB_ERROR 42000 42000
   1050 ER_TABLE_EXISTS_ERROR 42S01 42S01
   1051 ER_BAD_TABLE_ERROR 42S02 42S02
   1052 ER_NON_UNIQ_ERROR 23000 23000
   1053 ER_SERVER_SHUTDOWN 08S01 08S01
   1054 ER_BAD_FIELD_ERROR S0022 42S22
   1055 ER_WRONG_FIELD_WITH_GROUP S1009 42000
   1056 ER_WRONG_GROUP_FIELD S1009 42000
   1057 ER_WRONG_SUM_SELECT S1009 42000
   1058 ER_WRONG_VALUE_COUNT 21S01 21S01
   1059 ER_TOO_LONG_IDENT S1009 42000
   1060 ER_DUP_FIELDNAME S1009 42S21
   1061 ER_DUP_KEYNAME S1009 42000
   1062 ER_DUP_ENTRY S1009 23000
   1063 ER_WRONG_FIELD_SPEC S1009 42000
   1064 ER_PARSE_ERROR 42000 42000
   1065 ER_EMPTY_QUERY 42000 42000
   1066 ER_NONUNIQ_TABLE S1009 42000
   1067 ER_INVALID_DEFAULT S1009 42000
   1068 ER_MULTIPLE_PRI_KEY S1009 42000
   1069 ER_TOO_MANY_KEYS S1009 42000
   1070 ER_TOO_MANY_KEY_PARTS S1009 42000
   1071 ER_TOO_LONG_KEY S1009 42000
   1072 ER_KEY_COLUMN_DOES_NOT_EXITS S1009 42000
   1073 ER_BLOB_USED_AS_KEY S1009 42000
   1074 ER_TOO_BIG_FIELDLENGTH S1009 42000
   1075 ER_WRONG_AUTO_KEY S1009 42000
   1080 ER_FORCING_CLOSE 08S01 08S01
   1081 ER_IPSOCK_ERROR 08S01 08S01
   1082 ER_NO_SUCH_INDEX S1009 42S12
   1083 ER_WRONG_FIELD_TERMINATORS S1009 42000
   1084 ER_BLOBS_AND_NO_TERMINATED S1009 42000
   1090 ER_CANT_REMOVE_ALL_FIELDS 42000 42000
   1091 ER_CANT_DROP_FIELD_OR_KEY 42000 42000
   1101 ER_BLOB_CANT_HAVE_DEFAULT 42000 42000
   1102 ER_WRONG_DB_NAME 42000 42000
   1103 ER_WRONG_TABLE_NAME 42000 42000
   1104 ER_TOO_BIG_SELECT 42000 42000
   1106 ER_UNKNOWN_PROCEDURE 42000 42000
   1107 ER_WRONG_PARAMCOUNT_TO_PROCEDURE 42000 42000
   1109 ER_UNKNOWN_TABLE 42S02 42S02
   1110 ER_FIELD_SPECIFIED_TWICE 42000 42000
   1112 ER_UNSUPPORTED_EXTENSION 42000 42000
   1113 ER_TABLE_MUST_HAVE_COLUMNS 42000 42000
   1115 ER_UNKNOWN_CHARACTER_SET 42000 42000
   1118 ER_TOO_BIG_ROWSIZE 42000 42000
   1120 ER_WRONG_OUTER_JOIN 42000 42000
   1121 ER_NULL_COLUMN_IN_INDEX 42000 42000
   1129 ER_HOST_IS_BLOCKED 08004 HY000
   1130 ER_HOST_NOT_PRIVILEGED 08004 HY000
   1131 ER_PASSWORD_ANONYMOUS_USER 42000 42000
   1132 ER_PASSWORD_NOT_ALLOWED 42000 42000
   1133 ER_PASSWORD_NO_MATCH 42000 42000
   1136 ER_WRONG_VALUE_COUNT_ON_ROW 21S01 21S01
   1138 ER_INVALID_USE_OF_NULL S1000 42000
   1139 ER_REGEXP_ERROR 42000 42000
   1140 ER_MIX_OF_GROUP_FUNC_AND_FIELDS 42000 42000
   1141 ER_NONEXISTING_GRANT 42000 42000
   1142 ER_TABLEACCESS_DENIED_ERROR 42000 42000
   1143 ER_COLUMNACCESS_DENIED_ERROR 42000 42000
   1144 ER_ILLEGAL_GRANT_FOR_TABLE 42000 42000
   1145 ER_GRANT_WRONG_HOST_OR_USER 42000 42000
   1146 ER_NO_SUCH_TABLE 42S02 42S02
   1147 ER_NONEXISTING_TABLE_GRANT 42000 42000
   1148 ER_NOT_ALLOWED_COMMAND 42000 42000
   1149 ER_SYNTAX_ERROR 42000 42000
   1152 ER_ABORTING_CONNECTION 08S01 08S01
   1153 ER_NET_PACKET_TOO_LARGE 08S01 08S01
   1154 ER_NET_READ_ERROR_FROM_PIPE 08S01 08S01
   1155 ER_NET_FCNTL_ERROR 08S01 08S01
   1156 ER_NET_PACKETS_OUT_OF_ORDER 08S01 08S01
   1157 ER_NET_UNCOMPRESS_ERROR 08S01 08S01
   1158 ER_NET_READ_ERROR 08S01 08S01
   1159 ER_NET_READ_INTERRUPTED 08S01 08S01
   1160 ER_NET_ERROR_ON_WRITE 08S01 08S01
   1161 ER_NET_WRITE_INTERRUPTED 08S01 08S01
   1162 ER_TOO_LONG_STRING 42000 42000
   1163 ER_TABLE_CANT_HANDLE_BLOB 42000 42000
   1164 ER_TABLE_CANT_HANDLE_AUTO_INCREMENT 42000 42000
   1166 ER_WRONG_COLUMN_NAME 42000 42000
   1167 ER_WRONG_KEY_COLUMN 42000 42000
   1169 ER_DUP_UNIQUE 23000 23000
   1170 ER_BLOB_KEY_WITHOUT_LENGTH 42000 42000
   1171 ER_PRIMARY_CANT_HAVE_NULL 42000 42000
   1172 ER_TOO_MANY_ROWS 42000 42000
   1173 ER_REQUIRES_PRIMARY_KEY 42000 42000
   1176 ER_KEY_DOES_NOT_EXITS 42000 42000
   1177 ER_CHECK_NO_SUCH_TABLE 42000 42000
   1178 ER_CHECK_NOT_IMPLEMENTED 42000 42000
   1179 ER_CANT_DO_THIS_DURING_AN_TRANSACTION 25000 25000
   1184 ER_NEW_ABORTING_CONNECTION 08S01 08S01
   1189 ER_MASTER_NET_READ 08S01 08S01
   1190 ER_MASTER_NET_WRITE 08S01 08S01
   1203 ER_TOO_MANY_USER_CONNECTIONS 42000 42000
   1205 ER_LOCK_WAIT_TIMEOUT 40001 40001
   1207 ER_READ_ONLY_TRANSACTION 25000 25000
   1211 ER_NO_PERMISSION_TO_CREATE_USER 42000 42000
   1213 ER_LOCK_DEADLOCK 40001 40001
   1216 ER_NO_REFERENCED_ROW 23000 23000
   1217 ER_ROW_IS_REFERENCED 23000 23000
   1218 ER_CONNECT_TO_MASTER 08S01 08S01
   1222 ER_WRONG_NUMBER_OF_COLUMNS_IN_SELECT 21000 21000
   1226 ER_USER_LIMIT_REACHED 42000 42000
   1227 ER_SPECIFIC_ACCESS_DENIED_ERROR 42000 42000
   1230 ER_NO_DEFAULT 42000 42000
   1231 ER_WRONG_VALUE_FOR_VAR 42000 42000
   1232 ER_WRONG_TYPE_FOR_VAR 42000 42000
   1234 ER_CANT_USE_OPTION_HERE 42000 42000
   1235 ER_NOT_SUPPORTED_YET 42000 42000
   1239 ER_WRONG_FK_DEF 42000 42000
   1241 ER_OPERAND_COLUMNS 21000 21000
   1242 ER_SUBQUERY_NO_1_ROW 21000 21000
   1247 ER_ILLEGAL_REFERENCE 42S22 42S22
   1248 ER_DERIVED_MUST_HAVE_ALIAS 42000 42000
   1249 ER_SELECT_REDUCED 01000 01000
   1250 ER_TABLENAME_NOT_ALLOWED_HERE 42000 42000
   1251 ER_NOT_SUPPORTED_AUTH_MODE 08004 08004
   1252 ER_SPATIAL_CANT_HAVE_NULL 42000 42000
   1253 ER_COLLATION_CHARSET_MISMATCH 42000 42000
   1261 ER_WARN_TOO_FEW_RECORDS 01000 01000
   1262 ER_WARN_TOO_MANY_RECORDS 01000 01000
   1263 ER_WARN_NULL_TO_NOTNULL S1000 01000
   1264 ER_WARN_DATA_OUT_OF_RANGE 01000 01000
   1265 ER_WARN_DATA_TRUNCATED 01000 01000
   1280 ER_WRONG_NAME_FOR_INDEX 42000 42000
   1281 ER_WRONG_NAME_FOR_CATALOG 42000 42000
   1286 ER_UNKNOWN_STORAGE_ENGINE 42000 42000
   1292 ER_TRUNCATED_WRONG_VALUE 22007 22007
   1303 ER_SP_NO_RECURSIVE_CREATE S1000 2F003
   1304 ER_SP_ALREADY_EXISTS 42000 42000
   1305 ER_SP_DOES_NOT_EXIST 42000 42000
   1308 ER_SP_LILABEL_MISMATCH 42000 42000
   1309 ER_SP_LABEL_REDEFINE 42000 42000
   1310 ER_SP_LABEL_MISMATCH 42000 42000
   1311 ER_SP_UNINIT_VAR 01000 01000
   1312 ER_SP_BADSELECT 0A000 0A000
   1313 ER_SP_BADRETURN 42000 42000
   1314 ER_SP_BADSTATEMENT 0A000 0A000
   1315 ER_UPDATE_LOG_DEPRECATED_IGNORED 42000 42000
   1316 ER_UPDATE_LOG_DEPRECATED_TRANSLATED 42000 42000
   1317 ER_QUERY_INTERRUPTED S1000 70100
   1318 ER_SP_WRONG_NO_OF_ARGS 42000 42000
   1319 ER_SP_COND_MISMATCH 42000 42000
   1320 ER_SP_NORETURN 42000 42000
   1321 ER_SP_NORETURNEND S1000 2F005
   1322 ER_SP_BAD_CURSOR_QUERY 42000 42000
   1323 ER_SP_BAD_CURSOR_SELECT 42000 42000
   1324 ER_SP_CURSOR_MISMATCH 42000 42000
   1325 ER_SP_CURSOR_ALREADY_OPEN 24000 24000
   1326 ER_SP_CURSOR_NOT_OPEN 24000 24000
   1327 ER_SP_UNDECLARED_VAR 42000 42000
   1329 ER_SP_FETCH_NO_DATA S1000 02000
   1330 ER_SP_DUP_PARAM 42000 42000
   1331 ER_SP_DUP_VAR 42000 42000
   1332 ER_SP_DUP_COND 42000 42000
   1333 ER_SP_DUP_CURS 42000 42000
   1335 ER_SP_SUBSELECT_NYI 0A000 0A000
   1336 ER_STMT_NOT_ALLOWED_IN_SF_OR_TRG 0A000 0A000
   1337 ER_SP_VARCOND_AFTER_CURSHNDLR 42000 42000
   1338 ER_SP_CURSOR_AFTER_HANDLER 42000 42000
   1339 ER_SP_CASE_NOT_FOUND S1000 20000
   1365 ER_DIVISION_BY_ZERO 22012 22012
   1367 ER_ILLEGAL_VALUE_FOR_TYPE 22007 22007
   1370 ER_PROCACCESS_DENIED_ERROR 42000 42000
   1397 ER_XAER_NOTA S1000 XAE04
   1398 ER_XAER_INVAL S1000 XAE05
   1399 ER_XAER_RMFAIL S1000 XAE07
   1400 ER_XAER_OUTSIDE S1000 XAE09
   1401 ER_XA_RMERR S1000 XAE03
   1402 ER_XA_RBROLLBACK S1000 XA100
   1403 ER_NONEXISTING_PROC_GRANT 42000 42000
   1406 ER_DATA_TOO_LONG 22001 22001
   1407 ER_SP_BAD_SQLSTATE 42000 42000
   1410 ER_CANT_CREATE_USER_WITH_GRANT 42000 42000
   1413 ER_SP_DUP_HANDLER 42000 42000
   1414 ER_SP_NOT_VAR_ARG 42000 42000
   1415 ER_SP_NO_RETSET 0A000 0A000
   1416 ER_CANT_CREATE_GEOMETRY_OBJECT 22003 22003
   1425 ER_TOO_BIG_SCALE 42000 42000
   1426 ER_TOO_BIG_PRECISION 42000 42000
   1427 ER_M_BIGGER_THAN_D 42000 42000
   1437 ER_TOO_LONG_BODY 42000 42000
   1439 ER_TOO_BIG_DISPLAYWIDTH 42000 42000
   1440 ER_XAER_DUPID S1000 XAE08
   1441 ER_DATETIME_FUNCTION_OVERFLOW 22008 22008
   1451 ER_ROW_IS_REFERENCED_2 23000 23000
   1452 ER_NO_REFERENCED_ROW_2 23000 23000
   1453 ER_SP_BAD_VAR_SHADOW 42000 42000
   1458 ER_SP_WRONG_NAME 42000 42000
   1460 ER_SP_NO_AGGREGATE 42000 42000
   1461 ER_MAX_PREPARED_STMT_COUNT_REACHED 42000 42000
   1463 ER_NON_GROUPING_FIELD_USED 42000 42000
   1557 ER_FOREIGN_DUPLICATE_KEY 23000 23000
   1568 ER_CANT_CHANGE_TX_ISOLATION S1000 25001
   1582 ER_WRONG_PARAMCOUNT_TO_NATIVE_FCT 42000 42000
   1583 ER_WRONG_PARAMETERS_TO_NATIVE_FCT 42000 42000
   1584 ER_WRONG_PARAMETERS_TO_STORED_FCT 42000 42000
   1586 ER_DUP_ENTRY_WITH_KEY_NAME 23000 23000
   1613 ER_XA_RBTIMEOUT S1000 XA106
   1614 ER_XA_RBDEADLOCK S1000 XA102
   1630 ER_FUNC_INEXISTENT_NAME_COLLISION 42000 42000
   1641 ER_DUP_SIGNAL_SET 42000 42000
   1642 ER_SIGNAL_WARN 01000 01000
   1643 ER_SIGNAL_NOT_FOUND S1000 02000
   1645 ER_RESIGNAL_WITHOUT_ACTIVE_HANDLER S1000 0K000
   1687 ER_SPATIAL_MUST_HAVE_GEOM_COL 42000 42000
   1690 ER_DATA_OUT_OF_RANGE 22003 22003
   1698 ER_ACCESS_DENIED_NO_PASSWORD_ERROR 28000 28000
   1701 ER_TRUNCATE_ILLEGAL_FK 42000 42000
   1758 ER_DA_INVALID_CONDITION_NUMBER 35000 35000
   1761 ER_FOREIGN_DUPLICATE_KEY_WITH_CHILD_INFO 23000 23000
   1762 ER_FOREIGN_DUPLICATE_KEY_WITHOUT_CHILD_INFO 23000 23000
   1792 ER_CANT_EXECUTE_IN_READ_ONLY_TRANSACTION S1000 25006
   1845 ER_ALTER_OPERATION_NOT_SUPPORTED 0A000 0A000
   1846 ER_ALTER_OPERATION_NOT_SUPPORTED_REASON 0A000 0A000
   1859 ER_DUP_UNKNOWN_IN_INDEX 23000 23000
   1873 ER_ACCESS_DENIED_CHANGE_USER_ERROR 28000 28000
   1887 ER_GET_STACKED_DA_WITHOUT_ACTIVE_HANDLER S1000 0Z002
   1903 ER_INVALID_ARGUMENT_FOR_LOGARITHM S1000 2201E

Chapter 6 JDBC Concepts

   This section provides some general JDBC background.

6.1 Connecting to MySQL Using the JDBC DriverManager Interface

   When you are using JDBC outside of an application server, the
   DriverManager class manages the establishment of connections.

   Specify to the DriverManager which JDBC drivers to try to
   make Connections with. The easiest way to do this is to use
   Class.forName() on the class that implements the
   java.sql.Driver interface. With MySQL Connector/J, the name
   of this class is com.mysql.jdbc.Driver. With this method, you
   could use an external configuration file to supply the driver
   class name and driver parameters to use when connecting to a
   database.

   The following section of Java code shows how you might
   register MySQL Connector/J from the main() method of your
   application. If testing this code, first read the
   installation section at Chapter 3, "Connector/J
   Installation," to make sure you have connector installed
   correctly and the CLASSPATH set up. Also, ensure that MySQL
   is configured to accept external TCP/IP connections.
import java.sql.Connection;
import java.sql.DriverManager;
import java.sql.SQLException;

// Notice, do not import com.mysql.jdbc.*
// or you will have problems!

public class LoadDriver {
    public static void main(String[] args) {
        try {
            // The newInstance() call is a work around for some
            // broken Java implementations

            Class.forName("com.mysql.jdbc.Driver").newInstance();
        } catch (Exception ex) {
            // handle the error
        }
    }
}

   After the driver has been registered with the DriverManager,
   you can obtain a Connection instance that is connected to a
   particular database by calling DriverManager.getConnection():

   Example 6.1 Connector/J: Obtaining a connection from the
   DriverManager

   If you have not already done so, please review the portion of
   Section 6.1, "Connecting to MySQL Using the JDBC
   DriverManager Interface" above before working with the
   example below.

   This example shows how you can obtain a Connection instance
   from the DriverManager. There are a few different signatures
   for the getConnection() method. Consult the API documentation
   that comes with your JDK for more specific information on how
   to use them.
import java.sql.Connection;
import java.sql.DriverManager;
import java.sql.SQLException;

Connection conn = null;
...
try {
    conn =
       DriverManager.getConnection("jdbc:mysql://localhost/test?" +
                                   "user=minty&password=greatsqldb");

    // Do something with the Connection

   ...
} catch (SQLException ex) {
    // handle any errors
    System.out.println("SQLException: " + ex.getMessage());
    System.out.println("SQLState: " + ex.getSQLState());
    System.out.println("VendorError: " + ex.getErrorCode());
}

   Once a Connection is established, it can be used to create
   Statement and PreparedStatement objects, as well as retrieve
   metadata about the database. This is explained in the
   following sections.

6.2 Using JDBC Statement Objects to Execute SQL

   Statement objects allow you to execute basic SQL queries and
   retrieve the results through the ResultSet class, which is
   described later.

   To create a Statement instance, you call the
   createStatement() method on the Connection object you have
   retrieved using one of the DriverManager.getConnection() or
   DataSource.getConnection() methods described earlier.

   Once you have a Statement instance, you can execute a SELECT
   (http://dev.mysql.com/doc/refman/5.7/en/select.html) query by
   calling the executeQuery(String) method with the SQL you want
   to use.

   To update data in the database, use the executeUpdate(String
   SQL) method. This method returns the number of rows matched
   by the update statement, not the number of rows that were
   modified.

   If you do not know ahead of time whether the SQL statement
   will be a SELECT
   (http://dev.mysql.com/doc/refman/5.7/en/select.html) or an
   UPDATE
   (http://dev.mysql.com/doc/refman/5.7/en/update.html)/INSERT
   (http://dev.mysql.com/doc/refman/5.7/en/insert.html), then
   you can use the execute(String SQL) method. This method will
   return true if the SQL query was a SELECT
   (http://dev.mysql.com/doc/refman/5.7/en/select.html), or
   false if it was an UPDATE
   (http://dev.mysql.com/doc/refman/5.7/en/update.html), INSERT
   (http://dev.mysql.com/doc/refman/5.7/en/insert.html), or
   DELETE (http://dev.mysql.com/doc/refman/5.7/en/delete.html)
   statement. If the statement was a SELECT
   (http://dev.mysql.com/doc/refman/5.7/en/select.html) query,
   you can retrieve the results by calling the getResultSet()
   method. If the statement was an UPDATE
   (http://dev.mysql.com/doc/refman/5.7/en/update.html), INSERT
   (http://dev.mysql.com/doc/refman/5.7/en/insert.html), or
   DELETE (http://dev.mysql.com/doc/refman/5.7/en/delete.html)
   statement, you can retrieve the affected rows count by
   calling getUpdateCount() on the Statement instance.

   Example 6.2 Connector/J: Using java.sql.Statement to execute
   a SELECT query
import java.sql.Connection;
import java.sql.DriverManager;
import java.sql.SQLException;
import java.sql.Statement;
import java.sql.ResultSet;

// assume that conn is an already created JDBC connection (see previou
s examples)

Statement stmt = null;
ResultSet rs = null;

try {
    stmt = conn.createStatement();
    rs = stmt.executeQuery("SELECT foo FROM bar");

    // or alternatively, if you don't know ahead of time that
    // the query will be a SELECT...

    if (stmt.execute("SELECT foo FROM bar")) {
        rs = stmt.getResultSet();
    }

    // Now do something with the ResultSet ....
}
catch (SQLException ex){
    // handle any errors
    System.out.println("SQLException: " + ex.getMessage());
    System.out.println("SQLState: " + ex.getSQLState());
    System.out.println("VendorError: " + ex.getErrorCode());
}
finally {
    // it is a good idea to release
    // resources in a finally{} block
    // in reverse-order of their creation
    // if they are no-longer needed

    if (rs != null) {
        try {
            rs.close();
        } catch (SQLException sqlEx) { } // ignore

        rs = null;
    }

    if (stmt != null) {
        try {
            stmt.close();
        } catch (SQLException sqlEx) { } // ignore

        stmt = null;
    }
}

6.3 Using JDBC CallableStatements to Execute Stored Procedures

   Starting with MySQL server version 5.0 when used with
   Connector/J 3.1.1 or newer, the java.sql.CallableStatement
   interface is fully implemented with the exception of the
   getParameterMetaData() method.

   For more information on MySQL stored procedures, please refer
   to Using Stored Routines (Procedures and Functions)
   (http://dev.mysql.com/doc/refman/5.7/en/stored-routines.html)
   .

   Connector/J exposes stored procedure functionality through
   JDBC's CallableStatement interface.
   Note

   Current versions of MySQL server do not return enough
   information for the JDBC driver to provide result set
   metadata for callable statements. This means that when using
   CallableStatement, ResultSetMetaData may return NULL.

   The following example shows a stored procedure that returns
   the value of inOutParam incremented by 1, and the string
   passed in using inputParam as a ResultSet:

   Example 6.3 Connector/J: Calling Stored Procedures
CREATE PROCEDURE demoSp(IN inputParam VARCHAR(255), \
                        INOUT inOutParam INT)
BEGIN
    DECLARE z INT;
    SET z = inOutParam + 1;
    SET inOutParam = z;

    SELECT inputParam;

    SELECT CONCAT('zyxw', inputParam);
END

   To use the demoSp procedure with Connector/J, follow these
   steps:

    1. Prepare the callable statement by using
       Connection.prepareCall().
       Notice that you have to use JDBC escape syntax, and that
       the parentheses surrounding the parameter placeholders
       are not optional:
       Example 6.4 Connector/J: Using Connection.prepareCall()
import java.sql.CallableStatement;

...

    //
    // Prepare a call to the stored procedure 'demoSp'
    // with two parameters
    //
    // Notice the use of JDBC-escape syntax ({call ...})
    //

    CallableStatement cStmt = conn.prepareCall("{call demoSp(?, ?)}");



    cStmt.setString(1, "abcdefg");

       Note
       Connection.prepareCall() is an expensive method, due to
       the metadata retrieval that the driver performs to
       support output parameters. For performance reasons,
       minimize unnecessary calls to Connection.prepareCall() by
       reusing CallableStatement instances in your code.

    2. Register the output parameters (if any exist)
       To retrieve the values of output parameters (parameters
       specified as OUT or INOUT when you created the stored
       procedure), JDBC requires that they be specified before
       statement execution using the various
       registerOutputParameter() methods in the
       CallableStatement interface:
       Example 6.5 Connector/J: Registering output parameters
import java.sql.Types;
...
//
// Connector/J supports both named and indexed
// output parameters. You can register output
// parameters using either method, as well
// as retrieve output parameters using either
// method, regardless of what method was
// used to register them.
//
// The following examples show how to use
// the various methods of registering
// output parameters (you should of course
// use only one registration per parameter).
//

//
// Registers the second parameter as output, and
// uses the type 'INTEGER' for values returned from
// getObject()
//

cStmt.registerOutParameter(2, Types.INTEGER);

//
// Registers the named parameter 'inOutParam', and
// uses the type 'INTEGER' for values returned from
// getObject()
//

cStmt.registerOutParameter("inOutParam", Types.INTEGER);
...


    3. Set the input parameters (if any exist)
       Input and in/out parameters are set as for
       PreparedStatement objects. However, CallableStatement
       also supports setting parameters by name:
       Example 6.6 Connector/J: Setting CallableStatement input
       parameters
...

    //
    // Set a parameter by index
    //

    cStmt.setString(1, "abcdefg");

    //
    // Alternatively, set a parameter using
    // the parameter name
    //

    cStmt.setString("inputParameter", "abcdefg");

    //
    // Set the 'in/out' parameter using an index
    //

    cStmt.setInt(2, 1);

    //
    // Alternatively, set the 'in/out' parameter
    // by name
    //

    cStmt.setInt("inOutParam", 1);

...


    4. Execute the CallableStatement, and retrieve any result
       sets or output parameters.
       Although CallableStatement supports calling any of the
       Statement execute methods (executeUpdate(),
       executeQuery() or execute()), the most flexible method to
       call is execute(), as you do not need to know ahead of
       time if the stored procedure returns result sets:
       Example 6.7 Connector/J: Retrieving results and output
       parameter values
...

    boolean hadResults = cStmt.execute();

    //
    // Process all returned result sets
    //

    while (hadResults) {
        ResultSet rs = cStmt.getResultSet();

        // process result set
        ...

        hadResults = cStmt.getMoreResults();
    }

    //
    // Retrieve output parameters
    //
    // Connector/J supports both index-based and
    // name-based retrieval
    //

    int outputValue = cStmt.getInt(2); // index-based

    outputValue = cStmt.getInt("inOutParam"); // name-based

...

6.4 Retrieving AUTO_INCREMENT Column Values through JDBC

   Before version 3.0 of the JDBC API, there was no standard way
   of retrieving key values from databases that supported auto
   increment or identity columns. With older JDBC drivers for
   MySQL, you could always use a MySQL-specific method on the
   Statement interface, or issue the query SELECT
   LAST_INSERT_ID() after issuing an INSERT
   (http://dev.mysql.com/doc/refman/5.7/en/insert.html) to a
   table that had an AUTO_INCREMENT key. Using the
   MySQL-specific method call isn't portable, and issuing a
   SELECT (http://dev.mysql.com/doc/refman/5.7/en/select.html)
   to get the AUTO_INCREMENT key's value requires another
   round-trip to the database, which isn't as efficient as
   possible. The following code snippets demonstrate the three
   different ways to retrieve AUTO_INCREMENT values. First, we
   demonstrate the use of the new JDBC 3.0 method
   getGeneratedKeys() which is now the preferred method to use
   if you need to retrieve AUTO_INCREMENT keys and have access
   to JDBC 3.0. The second example shows how you can retrieve
   the same value using a standard SELECT LAST_INSERT_ID()
   query. The final example shows how updatable result sets can
   retrieve the AUTO_INCREMENT value when using the insertRow()
   method.

   Example 6.8 Connector/J: Retrieving AUTO_INCREMENT column
   values using Statement.getGeneratedKeys()
Statement stmt = null;
ResultSet rs = null;

try {

    //
    // Create a Statement instance that we can use for
    // 'normal' result sets assuming you have a
    // Connection 'conn' to a MySQL database already
    // available

    stmt = conn.createStatement();

    //
    // Issue the DDL queries for the table for this example
    //

    stmt.executeUpdate("DROP TABLE IF EXISTS autoIncTutorial");
    stmt.executeUpdate(
            "CREATE TABLE autoIncTutorial ("

            + "priKey INT NOT NULL AUTO_INCREMENT, "

            + "dataField VARCHAR(64), PRIMARY KEY (priKey))");

    //
    // Insert one row that will generate an AUTO INCREMENT
    // key in the 'priKey' field
    //

    stmt.executeUpdate(
            "INSERT INTO autoIncTutorial (dataField) "

            + "values ('Can I Get the Auto Increment Field?')",
            Statement.RETURN_GENERATED_KEYS);

    //
    // Example of using Statement.getGeneratedKeys()
    // to retrieve the value of an auto-increment
    // value
    //

    int autoIncKeyFromApi = -1;

    rs = stmt.getGeneratedKeys();

    if (rs.next()) {
        autoIncKeyFromApi = rs.getInt(1);
    } else {

        // throw an exception from here
    }

    System.out.println("Key returned from getGeneratedKeys():"

        + autoIncKeyFromApi);
} finally {

    if (rs != null) {
        try {
            rs.close();
        } catch (SQLException ex) {
            // ignore
        }
    }

    if (stmt != null) {
        try {
            stmt.close();
        } catch (SQLException ex) {
            // ignore
        }
    }
}

   Example 6.9 Connector/J: Retrieving AUTO_INCREMENT column
   values using SELECT LAST_INSERT_ID()
Statement stmt = null;
ResultSet rs = null;

try {

    //
    // Create a Statement instance that we can use for
    // 'normal' result sets.

    stmt = conn.createStatement();

    //
    // Issue the DDL queries for the table for this example
    //

    stmt.executeUpdate("DROP TABLE IF EXISTS autoIncTutorial");
    stmt.executeUpdate(
            "CREATE TABLE autoIncTutorial ("

            + "priKey INT NOT NULL AUTO_INCREMENT, "

            + "dataField VARCHAR(64), PRIMARY KEY (priKey))");

    //
    // Insert one row that will generate an AUTO INCREMENT
    // key in the 'priKey' field
    //

    stmt.executeUpdate(
            "INSERT INTO autoIncTutorial (dataField) "

            + "values ('Can I Get the Auto Increment Field?')");

    //
    // Use the MySQL LAST_INSERT_ID()
    // function to do the same thing as getGeneratedKeys()
    //

    int autoIncKeyFromFunc = -1;
    rs = stmt.executeQuery("SELECT LAST_INSERT_ID()");

    if (rs.next()) {
        autoIncKeyFromFunc = rs.getInt(1);
    } else {
        // throw an exception from here
    }

    System.out.println("Key returned from " +
                       "'SELECT LAST_INSERT_ID()': " +
                       autoIncKeyFromFunc);

} finally {

    if (rs != null) {
        try {
            rs.close();
        } catch (SQLException ex) {
            // ignore
        }
    }

    if (stmt != null) {
        try {
            stmt.close();
        } catch (SQLException ex) {
            // ignore
        }
    }
}

   Example 6.10 Connector/J: Retrieving AUTO_INCREMENT column
   values in Updatable ResultSets
Statement stmt = null;
ResultSet rs = null;

try {

    //
    // Create a Statement instance that we can use for
    // 'normal' result sets as well as an 'updatable'
    // one, assuming you have a Connection 'conn' to
    // a MySQL database already available
    //

    stmt = conn.createStatement(java.sql.ResultSet.TYPE_FORWARD_ONLY,
                                java.sql.ResultSet.CONCUR_UPDATABLE);

    //
    // Issue the DDL queries for the table for this example
    //

    stmt.executeUpdate("DROP TABLE IF EXISTS autoIncTutorial");
    stmt.executeUpdate(
            "CREATE TABLE autoIncTutorial ("

            + "priKey INT NOT NULL AUTO_INCREMENT, "

            + "dataField VARCHAR(64), PRIMARY KEY (priKey))");

    //
    // Example of retrieving an AUTO INCREMENT key
    // from an updatable result set
    //

    rs = stmt.executeQuery("SELECT priKey, dataField "

       + "FROM autoIncTutorial");

    rs.moveToInsertRow();

    rs.updateString("dataField", "AUTO INCREMENT here?");
    rs.insertRow();

    //
    // the driver adds rows at the end
    //

    rs.last();

    //
    // We should now be on the row we just inserted
    //

    int autoIncKeyFromRS = rs.getInt("priKey");

    System.out.println("Key returned for inserted row: "

        + autoIncKeyFromRS);

} finally {

    if (rs != null) {
        try {
            rs.close();
        } catch (SQLException ex) {
            // ignore
        }
    }

    if (stmt != null) {
        try {
            stmt.close();
        } catch (SQLException ex) {
            // ignore
        }
    }
}

   Running the preceding example code should produce the
   following output:
Key returned from getGeneratedKeys(): 1
Key returned from SELECT LAST_INSERT_ID(): 1
Key returned for inserted row: 1

   At times, it can be tricky to use the SELECT LAST_INSERT_ID()
   query, as that function's value is scoped to a connection.
   So, if some other query happens on the same connection, the
   value is overwritten. On the other hand, the
   getGeneratedKeys() method is scoped by the Statement
   instance, so it can be used even if other queries happen on
   the same connection, but not on the same Statement instance.

Chapter 7 Connection Pooling with Connector/J

   Connection pooling is a technique of creating and managing a
   pool of connections that are ready for use by any thread
   (http://dev.mysql.com/doc/refman/5.7/en/glossary.html#glos_th
   read) that needs them. Connection pooling can greatly
   increase the performance of your Java application, while
   reducing overall resource usage.

How Connection Pooling Works

   Most applications only need a thread to have access to a JDBC
   connection when they are actively processing a transaction
   (http://dev.mysql.com/doc/refman/5.7/en/glossary.html#glos_tr
   ansaction), which often takes only milliseconds to complete.
   When not processing a transaction, the connection sits idle.
   Connection pooling enables the idle connection to be used by
   some other thread to do useful work.

   In practice, when a thread needs to do work against a MySQL
   or other database with JDBC, it requests a connection from
   the pool. When the thread is finished using the connection,
   it returns it to the pool, so that it can be used by any
   other threads.

   When the connection is loaned out from the pool, it is used
   exclusively by the thread that requested it. From a
   programming point of view, it is the same as if your thread
   called DriverManager.getConnection() every time it needed a
   JDBC connection. With connection pooling, your thread may end
   up using either a new connection or an already-existing
   connection.

Benefits of Connection Pooling

   The main benefits to connection pooling are:

     * Reduced connection creation time.
       Although this is not usually an issue with the quick
       connection setup that MySQL offers compared to other
       databases, creating new JDBC connections still incurs
       networking and JDBC driver overhead that will be avoided
       if connections are recycled.

     * Simplified programming model.
       When using connection pooling, each individual thread can
       act as though it has created its own JDBC connection,
       allowing you to use straightforward JDBC programming
       techniques.

     * Controlled resource usage.
       If you create a new connection every time a thread needs
       one rather than using connection pooling, your
       application's resource usage can be wasteful, and it
       could lead to unpredictable behaviors for your
       application when it is under a heavy load.

Using Connection Pooling with Connector/J

   The concept of connection pooling in JDBC has been
   standardized through the JDBC 2.0 Optional interfaces, and
   all major application servers have implementations of these
   APIs that work with MySQL Connector/J.

   Generally, you configure a connection pool in your
   application server configuration files, and access it through
   the Java Naming and Directory Interface (JNDI). The following
   code shows how you might use a connection pool from an
   application deployed in a J2EE application server:

   Example 7.1 Connector/J: Using a connection pool with a J2EE
   application server
import java.sql.Connection;
import java.sql.SQLException;
import java.sql.Statement;

import javax.naming.InitialContext;
import javax.sql.DataSource;


public class MyServletJspOrEjb {

    public void doSomething() throws Exception {
        /*

         * Create a JNDI Initial context to be able to

         *  lookup  the DataSource
         *

         * In production-level code, this should be cached as

         * an instance or static variable, as it can

         * be quite expensive to create a JNDI context.
         *

         * Note: This code only works when you are using servlets

         * or EJBs in a J2EE application server. If you are

         * using connection pooling in standalone Java code, you

         * will have to create/configure datasources using whatever

         * mechanisms your particular connection pooling library

         * provides.
         */

        InitialContext ctx = new InitialContext();

         /*

          * Lookup the DataSource, which will be backed by a pool

          * that the application server provides. DataSource instances

          * are also a good candidate for caching as an instance

          * variable, as JNDI lookups can be expensive as well.
          */

        DataSource ds =
          (DataSource)ctx.lookup("java:comp/env/jdbc/MySQLDB");

        /*

         * The following code is what would actually be in your

         * Servlet, JSP or EJB 'service' method...where you need

         * to work with a JDBC connection.
         */

        Connection conn = null;
        Statement stmt = null;

        try {
            conn = ds.getConnection();

            /*

             * Now, use normal JDBC programming to work with

             * MySQL, making sure to close each resource when you're

             * finished with it, which permits the connection pool

             * resources to be recovered as quickly as possible
             */

            stmt = conn.createStatement();
            stmt.execute("SOME SQL QUERY");

            stmt.close();
            stmt = null;

            conn.close();
            conn = null;
        } finally {
            /*

             * close any jdbc instances here that weren't

             * explicitly closed during normal code path, so

             * that we don't 'leak' resources...
             */

            if (stmt != null) {
                try {
                    stmt.close();
                } catch (sqlexception sqlex) {
                    // ignore, as we can't do anything about it here
                }

                stmt = null;
            }

            if (conn != null) {
                try {
                    conn.close();
                } catch (sqlexception sqlex) {
                    // ignore, as we can't do anything about it here
                }

                conn = null;
            }
        }
    }
}

   As shown in the example above, after obtaining the JNDI
   InitialContext, and looking up the DataSource, the rest of
   the code follows familiar JDBC conventions.

   When using connection pooling, always make sure that
   connections, and anything created by them (such as statements
   or result sets) are closed. This rule applies no matter what
   happens in your code (exceptions, flow-of-control, and so
   forth). When these objects are closed, they can be re-used;
   otherwise, they will be stranded, which means that the MySQL
   server resources they represent (such as buffers, locks, or
   sockets) are tied up for some time, or in the worst case can
   be tied up forever.

Sizing the Connection Pool

   Each connection to MySQL has overhead (memory, CPU, context
   switches, and so forth) on both the client and server side.
   Every connection limits how many resources there are
   available to your application as well as the MySQL server.
   Many of these resources will be used whether or not the
   connection is actually doing any useful work! Connection
   pools can be tuned to maximize performance, while keeping
   resource utilization below the point where your application
   will start to fail rather than just run slower.

   The optimal size for the connection pool depends on
   anticipated load and average database transaction time. In
   practice, the optimal connection pool size can be smaller
   than you might expect. If you take Oracle's Java Petstore
   blueprint application for example, a connection pool of 15-20
   connections can serve a relatively moderate load (600
   concurrent users) using MySQL and Tomcat with acceptable
   response times.

   To correctly size a connection pool for your application,
   create load test scripts with tools such as Apache JMeter or
   The Grinder, and load test your application.

   An easy way to determine a starting point is to configure
   your connection pool's maximum number of connections to be
   unbounded, run a load test, and measure the largest amount of
   concurrently used connections. You can then work backward
   from there to determine what values of minimum and maximum
   pooled connections give the best performance for your
   particular application.

Validating Connections

   MySQL Connector/J can validate the connection by executing a
   lightweight ping against a server. In the case of
   load-balanced connections, this is performed against all
   active pooled internal connections that are retained. This is
   beneficial to Java applications using connection pools, as
   the pool can use this feature to validate connections.
   Depending on your connection pool and configuration, this
   validation can be carried out at different times:

    1. Before the pool returns a connection to the application.

    2. When the application returns a connection to the pool.

    3. During periodic checks of idle connections.

   To use this feature, specify a validation query in your
   connection pool that starts with /* ping */. Note that the
   syntax must be exactly as specified. This will cause the
   driver send a ping to the server and return a dummy
   lightweight result set. When using a ReplicationConnection or
   LoadBalancedConnection, the ping will be sent across all
   active connections.

   It is critical that the syntax be specified correctly. The
   syntax needs to be exact for reasons of efficiency, as this
   test is done for every statement that is executed:

protected static final String PING_MARKER = "/* ping */";
...
if (sql.charAt(0) == '/') {
if (sql.startsWith(PING_MARKER)) {
doPingInstead();
...


   None of the following snippets will work, because the ping
   syntax is sensitive to whitespace, capitalization, and
   placement:
sql = "/* PING */ SELECT 1";
sql = "SELECT 1 /* ping*/";
sql = "/*ping*/ SELECT 1";
sql = " /* ping */ SELECT 1";
sql = "/*to ping or not to ping*/ SELECT 1";

   All of the previous statements will issue a normal SELECT
   statement and will not be transformed into the lightweight
   ping. Further, for load-balanced connections, the statement
   will be executed against one connection in the internal pool,
   rather than validating each underlying physical connection.
   This results in the non-active physical connections assuming
   a stale state, and they may die. If Connector/J then
   re-balances, it might select a dead connection, resulting in
   an exception being passed to the application. To help prevent
   this, you can use loadBalanceValidateConnectionOnSwapServer
   to validate the connection before use.

   If your Connector/J deployment uses a connection pool that
   allows you to specify a validation query, take advantage of
   it, but ensure that the query starts exactly with /* ping */.
   This is particularly important if you are using the
   load-balancing or replication-aware features of Connector/J,
   as it will help keep alive connections which otherwise will
   go stale and die, causing problems later.

Chapter 8 Multi-Host Connections

   The following sections discuss a number of topics that
   involve multi-host connections, namely, server
   load-balancing, failover, and replication.

   Developers should know the following things about multi-host
   connections that are managed through Connector/J:

     * Each multi-host connection is a wrapper of the underlying
       physical connections.

     * Each of the underlying physical connections has its own
       session. Sessions cannot be tracked, shared, or copied,
       given the MySQL architecture.

     * Every switch between physical connections means a switch
       between sessions.

     * Within a transaction boundary, there are no switches
       between physical connections. Beyond a transaction
       boundary, there is no guarantee that a switch does not
       occur.
       Note
       If an application reuses session-scope data (for example,
       variables, SSPs) beyond a transaction boundary, failures
       are possible, as a switch between the physical
       connections (which is also a switch between sessions)
       might occur. Therefore, the application should re-prepare
       the session data and also restart the last transaction in
       case of an exception, or it should re-prepare session
       data for each new transaction if it does not want to deal
       with exception handling.

8.1 Configuring Server Failover

   MySQL Connector/J supports server failover. A failover
   happens when connection-related errors occur for an
   underlying, active connection. The connection errors are, by
   default, propagated to the client, which has to handle them
   by, for example, recreating the working objects (Statement,
   ResultSet, etc.) and restarting the processes. Sometimes, the
   driver might eventually fall back to the original host
   automatically before the client application continues to run,
   in which case the host switch is transparent and the client
   application will not even notice it.

   A connection using failover support works just like a
   standard connection: the client does not experience any
   disruptions in the failover process. This means the client
   can rely on the same connection instance even if two
   successive statements might be executed on two different
   physical hosts. However, this does not mean the client does
   not have to deal with the exception that triggered the server
   switch.

   The failover is configured at the initial setup stage of the
   server connection by the connection URL (see explanations for
   its format here):
jdbc:mysql://[primary host][:port],[secondary host 1][:port][,[seconda
ry host 2][:port]]...[/[database]]??
[?propertyName1=propertyValue1[&propertyName2=propertyValue2]...]

   The host list in the connection URL comprises of two types of
   hosts, the primary and the secondary. When starting a new
   connection, the driver always tries to connect to the primary
   host first and, if required, fails over to the secondary
   hosts on the list sequentially when communication problems
   are experienced. Even if the initial connection to the
   primary host fails and the driver gets connected to a
   secondary host, the primary host never loses its special
   status: for example, it can be configured with an access mode
   distinct from those of the secondary hosts, and it can be put
   on a higher priority when a host is to be picked during a
   failover process.

   The failover support is configured by the following
   connection properties (their functions are explained in the
   paragraphs below):

     * failOverReadOnly

     * secondsBeforeRetryMaster

     * queriesBeforeRetryMaster

     * retriesAllDown

     * autoReconnect

     * autoReconnectForPools

Configuring Connection Access Mode

   As with any standard connection, the initial connection to
   the primary host is in read/write mode. However, if the
   driver fails to establish the initial connection to the
   primary host and it automatically switches to the next host
   on the list, the access mode now depends on the value of the
   property failOverReadOnly, which is "true" by default. The
   same happens if the driver is initially connected to the
   primary host and, because of some connection failure, it
   fails over to a secondary host. Every time the connection
   falls back to the primary host, its access mode will be
   read/write, irrespective of whether or not the primary host
   has been connected to before. The connection access mode can
   be changed any time at runtime by calling the method
   Connection.setReadOnly(boolean), which partially overrides
   the property failOverReadOnly. When failOverReadOnly=false
   and the access mode is explicitly set to either true or
   false, it becomes the mode for every connection after a host
   switch, no matter what host type are we connected to; but, if
   failOverReadOnly=true, changing the access mode to read/write
   is only possible if the driver is connecting to the primary
   host; however, even if the access mode cannot be changed for
   the current connection, the driver remembers the client's
   last intention and, when falling back to the primary host,
   that is the mode that will be used. For an illustration, see
   the following successions of events with a two-host
   connection.

     * Sequence A, with failOverReadOnly=true:

         1. Connects to primary host in read/write mode

         2. Sets Connection.setReadOnly(true); primary host now
            in read-only mode

         3. Failover event; connects to secondary host in
            read-only mode

         4. Sets Connection.setReadOnly(false); secondary host
            remains in read-only mode

         5. Falls back to primary host; connection now in
            read/write mode

     * Sequence B, with failOverReadOnly=false

         1. Connects to primary host in read/write mode

         2. Sets Connection.setReadOnly(true); primary host now
            in read-only mode

         3. Failover event; connects to secondary host in
            read-only mode

         4. Set Connection.setReadOnly(false); connection to
            secondary host switches to read/write mode

         5. Falls back to primary host; connection now in
            read/write mode

   The difference between the two scenarios is in step 4: the
   access mode for the secondary host in sequence A does not
   change at that step, but the driver remembers and uses the
   set mode when falling back to the primary host, which would
   be read-only otherwise; but in sequence B, the access mode
   for the secondary host changes immediately.

Configuring Fallback to Primary Host

   As already mentioned, the primary host is special in the
   failover arrangement when it comes to the host's access mode.
   Additionally, the driver tries to fall back to the primary
   host as soon as possible by default, even if no communication
   exception occurs. Two properties, secondsBeforeRetryMaster
   and queriesBeforeRetryMaster, determine when the driver is
   ready to retry a reconnection to the primary host (the Master
   in the property names stands for the primary host of our
   connection URL, which is not necessarily a master host in a
   replication setup; the naming was maintained for back
   compatibility with Connector/J versions prior to 5.1.35):

     * secondsBeforeRetryMaster determines how much time the
       driver waits before trying to fall back to the primary
       host

     * queriesBeforeRetryMaster determines the number of queries
       that are executed before the driver tries to fall back to
       the primary host. Note that for the driver, each call to
       a Statement.execute*() method increments the query
       execution counter; therefore, when calls are made to
       Statement.executeBatch() or if allowMultiQueries or
       rewriteBatchStatements are enabled, the driver may not
       have an accurate count of the actual number of queries
       executed on the server. Also, the driver calls the
       Statement.execute*() methods internally in several
       occasions. All these mean you can only use
       queriesBeforeRetryMaster only as a coarse specification
       for when to fall back to the primary host.

   In general, an attempt to fallback to the primary host is
   made when at least one of the conditions specified by the two
   properties is met, and the attempt always takes place at
   transaction boundaries. However, if auto-commit is turned
   off, the check happens only when the method
   Connection.commit() or Connection.rollback() is called. The
   automatic fallback to the primary host can be turned off by
   setting simultaneously secondsBeforeRetryMaster and
   queriesBeforeRetryMaster to "0". Setting only one of the
   properties to "0" only disables one part of the check.

Configuring Reconnection Attempts

   When establishing a new connection or when a failover event
   occurs, the driver tries to connect successively to the next
   candidate on the host list. When the end of the list has been
   reached, it restarts all over again from the beginning of the
   list; however, the primary host is skipped over, if (a) NOT
   all the secondary hosts have already been tested at least
   once, AND (b) the fallback conditions defined by
   secondsBeforeRetryMaster and queriesBeforeRetryMaster are not
   yet fulfilled. Each run-through of the whole host list,
   (which is not necessarily completed at the end of the host
   list) counts as a single connection attempt. The driver tries
   as many connection attempts as specified by the value of the
   property retriesAllDown.

Seamless Reconnection

   Although not recommended, you can make the driver perform
   failovers without invalidating the active Statement or
   ResultSet instances by setting either the parameter
   autoReconnect or autoReconnectForPools to true. This allows
   the client to continue using the same object instances after
   a failover event, without taking any exceptional measures.
   This, however, may lead to unexpected results: for example,
   if the driver is connected to the primary host with
   read/write access mode and it fails-over to a secondary host
   in real-only mode, further attempts to issue data-changing
   queries will result in errors, and the client will not be
   aware of that. This limitation is particularly relevant when
   using data streaming: after the failover, the ResultSet looks
   to be alright, but the underlying connection may have changed
   already, and no backing cursor is available anymore.

8.2 Configuring Load Balancing with Connector/J

   Connector/J has long provided an effective means to
   distribute read/write load across multiple MySQL server
   instances for Cluster or master-master replication
   deployments. Starting with Connector/J 5.1.3, you can now
   dynamically configure load-balanced connections, with no
   service outage. In-process transactions are not lost, and no
   application exceptions are generated if any application is
   trying to use that particular server instance.

   The load balancing is configured at the initial setup stage
   of the server connection by the following connection URL,
   which has a similar format as the general URL for MySQL
   connection, but a specialized scheme:
jdbc:mysql:loadbalance://[host1][:port],[host2][:port][,[host3][:port]
]...[/[database]] ??
[?propertyName1=propertyValue1[&propertyName2=propertyValue2]...]

   There are two configuration properties associated with this
   functionality:

     * loadBalanceConnectionGroup - This provides the ability to
       group connections from different sources. This allows you
       to manage these JDBC sources within a single class loader
       in any combination you choose. If they use the same
       configuration, and you want to manage them as a logical
       single group, give them the same name. This is the key
       property for management: if you do not define a name
       (string) for loadBalanceConnectionGroup, you cannot
       manage the connections. All load-balanced connections
       sharing the same loadBalanceConnectionGroup value,
       regardless of how the application creates them, will be
       managed together.

     * loadBalanceEnableJMX - The ability to manage the
       connections is exposed when you define a
       loadBalanceConnectionGroup; but if you want to manage
       this externally, enable JMX by setting this property to
       true. This enables a JMX implementation, which exposes
       the management and monitoring operations of a connection
       group. Further, start your application with the
       -Dcom.sun.management.jmxremote JVM flag. You can then
       perform connect and perform operations using a JMX client
       such as jconsole.

   Once a connection has been made using the correct connection
   properties, a number of monitoring properties are available:

     * Current active host count.

     * Current active physical connection count.

     * Current active logical connection count.

     * Total logical connections created.

     * Total transaction count.

   The following management operations can also be performed:

     * Add host.

     * Remove host.

   The JMX interface,
   com.mysql.jdbc.jmx.LoadBalanceConnectionGroupManagerMBean,
   has the following methods:

     * int getActiveHostCount(String group);

     * int getTotalHostCount(String group);

     * long getTotalLogicalConnectionCount(String group);

     * long getActiveLogicalConnectionCount(String group);

     * long getActivePhysicalConnectionCount(String group);

     * long getTotalPhysicalConnectionCount(String group);

     * long getTotalTransactionCount(String group);

     * void removeHost(String group, String host) throws
       SQLException;

     * void stopNewConnectionsToHost(String group, String host)
       throws SQLException;

     * void addHost(String group, String host, boolean
       forExisting);

     * String getActiveHostsList(String group);

     * String getRegisteredConnectionGroups();

   The getRegisteredConnectionGroups() method returns the names
   of all connection groups defined in that class loader.

   You can test this setup with the following code:

public class Test {

    private static String URL = "jdbc:mysql:loadbalance://" +
        "localhost:3306,localhost:3310/test?" +
        "loadBalanceConnectionGroup=first&loadBalanceEnableJMX=true";

    public static void main(String[] args) throws Exception {
        new Thread(new Repeater()).start();
        new Thread(new Repeater()).start();
        new Thread(new Repeater()).start();
    }

    static Connection getNewConnection() throws SQLException, ClassNot
FoundException {
        Class.forName("com.mysql.jdbc.Driver");
        return DriverManager.getConnection(URL, "root", "");
    }

    static void executeSimpleTransaction(Connection c, int conn, int t
rans){
        try {
            c.setAutoCommit(false);
            Statement s = c.createStatement();
            s.executeQuery("SELECT SLEEP(1) /* Connection: " + conn +
", transaction: " + trans + " */");
            c.commit();
        } catch (SQLException e) {
            e.printStackTrace();
        }
    }

    public static class Repeater implements Runnable {
        public void run() {
            for(int i=0; i < 100; i++){
                try {
                    Connection c = getNewConnection();
                    for(int j=0; j < 10; j++){
                        executeSimpleTransaction(c, i, j);
                        Thread.sleep(Math.round(100 * Math.random()));
                    }
                    c.close();
                    Thread.sleep(100);
                } catch (Exception e) {
                    e.printStackTrace();
                }
            }
        }
    }
}


   After compiling, the application can be started with the
   -Dcom.sun.management.jmxremote flag, to enable remote
   management. jconsole can then be started. The Test main class
   will be listed by jconsole. Select this and click Connect.
   You can then navigate to the
   com.mysql.jdbc.jmx.LoadBalanceConnectionGroupManager bean. At
   this point, you can click on various operations and examine
   the returned result.

   If you now had an additional instance of MySQL running on
   port 3309, you could ensure that Connector/J starts using it
   by using the addHost(), which is exposed in jconsole. Note
   that these operations can be performed dynamically without
   having to stop the application running.

   For further information on the combination of load balancing
   and failover, see Section 8.4, "Advanced Load-balancing and
   Failover Configuration."

8.3 Configuring Master/Slave Replication with Connector/J

   This section describe a number of features of Connector/J's
   support for replication-aware deployments.

   The replication is configured at the initial setup stage of
   the server connection by the connection URL, which has a
   similar format as the general URL for MySQL connection, but a
   specialized scheme:
jdbc:mysql:replication://[master host][:port],[slave host 1][:port][,[
slave host 2][:port]]...[/[database]] ??
[?propertyName1=propertyValue1[&propertyName2=propertyValue2]...]

   Users may specify the property
   allowMasterDownConnections=true to allow Connection objects
   to be created even though no master hosts are reachable. Such
   Connection objects report they are read-only, and
   isMasterConnection() returns false for them. The Connection
   tests for available master hosts when
   Connection.setReadOnly(false) is called, throwing an
   SQLException if it cannot establish a connection to a master,
   or switching to a master connection if the host is available.

   For Connector/J 5.1.38 and later, users may specify the
   property allowSlavesDownConnections=true to allow Connection
   objects to be created even though no slave hosts are
   reachable. A Connection then, at runtime, tests for available
   slave hosts when Connection.setReadOnly(true) is called (see
   explanation for the method below), throwing an SQLException
   if it cannot establish a connection to a slave, unless the
   property readFromMasterWhenNoSlaves is set to be "true" (see
   below for a description of the property).

Scaling out Read Load by Distributing Read Traffic to Slaves

   Connector/J 3.1.7 and higher includes a variant of the driver
   that will automatically send queries to a read/write master,
   or a failover or round-robin loadbalanced set of slaves based
   on the state of Connection.getReadOnly().

   An application signals that it wants a transaction to be
   read-only by calling Connection.setReadOnly(true). The
   replication-aware connection will use one of the slave
   connections, which are load-balanced per slave host using a
   round-robin scheme. A given connection is sticky to a slave
   until a transaction boundary command (a commit or rollback)
   is issued, or until the slave is removed from service. For
   Connector/J 5.1.38 and later, after calling
   Connection.setReadOnly(true), if you want to allow connection
   to a master when no slaves are available, set the property
   readFromMasterWhenNoSlaves to "true." Notice that the master
   host will be used in read-only state in those cases, as if it
   is a slave host. Also notice that setting
   readFromMasterWhenNoSlaves=true might result in an extra load
   for the master host in a transparent manner.

   If you have a write transaction, or if you have a read that
   is time-sensitive (remember, replication in MySQL is
   asynchronous), set the connection to be not read-only, by
   calling Connection.setReadOnly(false) and the driver will
   ensure that further calls are sent to the master MySQL
   server. The driver takes care of propagating the current
   state of autocommit, isolation level, and catalog between all
   of the connections that it uses to accomplish this load
   balancing functionality.

   To enable this functionality, use the
   com.mysql.jdbc.ReplicationDriver class when configuring your
   application server's connection pool or when creating an
   instance of a JDBC driver for your standalone application.
   Because it accepts the same URL format as the standard MySQL
   JDBC driver, ReplicationDriver does not currently work with
   java.sql.DriverManager-based connection creation unless it is
   the only MySQL JDBC driver registered with the DriverManager
   .

   Here is a short example of how ReplicationDriver might be
   used in a standalone application:
import java.sql.Connection;
import java.sql.ResultSet;
import java.util.Properties;

import com.mysql.jdbc.ReplicationDriver;

public class ReplicationDriverDemo {

  public static void main(String[] args) throws Exception {
    ReplicationDriver driver = new ReplicationDriver();

    Properties props = new Properties();

    // We want this for failover on the slaves
    props.put("autoReconnect", "true");

    // We want to load balance between the slaves
    props.put("roundRobinLoadBalance", "true");

    props.put("user", "foo");
    props.put("password", "bar");

    //
    // Looks like a normal MySQL JDBC url, with a
    // comma-separated list of hosts, the first
    // being the 'master', the rest being any number
    // of slaves that the driver will load balance against
    //

    Connection conn =
        driver.connect("jdbc:mysql:replication://master,slave1,slave2,
slave3/test",
            props);

    //
    // Perform read/write work on the master
    // by setting the read-only flag to "false"
    //

    conn.setReadOnly(false);
    conn.setAutoCommit(false);
    conn.createStatement().executeUpdate("UPDATE some_table ....");
    conn.commit();

    //
    // Now, do a query from a slave, the driver automatically picks on
e
    // from the list
    //

    conn.setReadOnly(true);

    ResultSet rs =
      conn.createStatement().executeQuery("SELECT a,b FROM alt_table")
;

     .......
  }
}

   Consider using the Load Balancing JDBC Pool (lbpool) tool,
   which provides a wrapper around the standard JDBC driver and
   enables you to use DB connection pools that includes checks
   for system failures and uneven load distribution. For more
   information, see Load Balancing JDBC Driver for MySQL
   (mysql-lbpool) (http://code.google.com/p/mysql-lbpool/).

Support for Multiple-Master Replication Topographies

   Since Connector/J 5.1.27, multi-master replication
   topographies are supported.

   The connection URL for replication discussed earlier (i.e.,
   in the format of
   jdbc:mysql:replication://master,slave1,slave2,slave3/test)
   assumes that the first (and only the first) host is the
   master. Supporting deployments with an arbitrary number of
   masters and slaves requires a different URL syntax for
   specifying the hosts and the properties for specific hosts,
   which is just an expansion of the URL syntax discussed in
   Section 5.1, "" with the property type=[master|slave]; for
   example:
jdbc:mysql://address=(type=master)(host=master1host),address=(type=mas
ter)(host=master2host),address=(type=slave)(host=slave1host)/database

   Connector/J uses a load-balanced connection internally for
   management of the master connections, which means that
   ReplicationConnection, when configured to use multiple
   masters, exposes the same options to balance load across
   master hosts as described in Section 8.2, "Configuring Load
   Balancing with Connector/J."

Live Reconfiguration of Replication Topography

   Since Connector/J 5.1.28, live management of replication host
   (single or multi-master) topographies is also supported. This
   enables users to promote slaves for Java applications without
   requiring an application restart.

   The replication hosts are most effectively managed in the
   context of a replication connection group. A
   ReplicationConnectionGroup class represents a logical
   grouping of connections which can be managed together. There
   may be one or more such replication connection groups in a
   given Java class loader (there can be an application with two
   different JDBC resources needing to be managed
   independently). This key class exposes host management
   methods for replication connections, and
   ReplicationConnection objects register themselves with the
   appropriate ReplicationConnectionGroup if a value for the new
   replicationConnectionGroup property is specified. The
   ReplicationConnectionGroup object tracks these connections
   until they are closed, and it is used to manipulate the hosts
   associated with these connections.

   Some important methods related to host management include:

     * getMasterHosts(): Returns a collection of strings
       representing the hosts configured as masters

     * getSlaveHosts(): Returns a collection of strings
       representing the hosts configured as slaves

     * addSlaveHost(String host): Adds new host to pool of
       possible slave hosts for selection at start of new
       read-only workload

     * promoteSlaveToMaster(String host): Removes the host from
       the pool of potential slaves for future read-only
       processes (existing read-only process is allowed to
       continue to completion) and adds the host to the pool of
       potential master hosts

     * removeSlaveHost(String host, boolean closeGently):
       Removes the host (host name match must be exact) from the
       list of configured slaves; if closeGently is false,
       existing connections which have this host as currently
       active will be closed hardly (application should expect
       exceptions)

     * removeMasterHost(String host, boolean closeGently): Same
       as removeSlaveHost(), but removes the host from the list
       of configured masters

   Some useful management metrics include:

     * getConnectionCountWithHostAsSlave(String host): Returns
       the number of ReplicationConnection objects that have the
       given host configured as a possible slave

     * getConnectionCountWithHostAsMaster(String host): Returns
       the number of ReplicationConnection objects that have the
       given host configured as a possible master

     * getNumberOfSlavesAdded(): Returns the number of times a
       slave host has been dynamically added to the group pool

     * getNumberOfSlavesRemoved(): Returns the number of times a
       slave host has been dynamically removed from the group
       pool

     * getNumberOfSlavePromotions(): Returns the number of times
       a slave host has been promoted to a master

     * getTotalConnectionCount(): Returns the number of
       ReplicationConnection objects which have been registered
       with this group

     * getActiveConnectionCount(): Returns the number of
       ReplicationConnection objects currently being managed by
       this group

ReplicationConnectionGroupManager

   com.mysql.jdbc.ReplicationConnectionGroupManager provides
   access to the replication connection groups, together with
   some utility methods.

     * getConnectionGroup(String groupName): Returns the
       ReplicationConnectionGroup object matching the groupName
       provided

   The other methods in ReplicationConnectionGroupManager mirror
   those of ReplicationConnectionGroup, except that the first
   argument is a String group name. These methods will operate
   on all matching ReplicationConnectionGroups, which are
   helpful for removing a server from service and have it
   decommissioned across all possible
   ReplicationConnectionGroups.

   These methods might be useful for in-JVM management of
   replication hosts if an application triggers topography
   changes. For managing host configurations from outside the
   JVM, JMX can be used.

Using JMX for Managing Replication Hosts

   When Connector/J is started with replicationEnableJMX=true
   and a value set for the property replicationConnectionGroup,
   a JMX MBean will be registered, allowing manipulation of
   replication hosts by a JMX client. The MBean interface is
   defined in com.mysql.jdbc.jmx.ReplicationGroupManagerMBean,
   and leverages the ReplicationConnectionGroupManager static
   methods:
 public abstract void addSlaveHost(String groupFilter, String host) th
rows SQLException;
 public abstract void removeSlaveHost(String groupFilter, String host)
 throws SQLException;
 public abstract void promoteSlaveToMaster(String groupFilter, String
host) throws SQLException;
 public abstract void removeMasterHost(String groupFilter, String host
) throws SQLException;
 public abstract String getMasterHostsList(String group);
 public abstract String getSlaveHostsList(String group);
 public abstract String getRegisteredConnectionGroups();
 public abstract int getActiveMasterHostCount(String group);
 public abstract int getActiveSlaveHostCount(String group);
 public abstract int getSlavePromotionCount(String group);
 public abstract long getTotalLogicalConnectionCount(String group);
 public abstract long getActiveLogicalConnectionCount(String group);

8.4 Advanced Load-balancing and Failover Configuration

   Connector/J provides a useful load-balancing implementation
   for MySQL Cluster or multi-master deployments, as explained
   in Section 8.2, "Configuring Load Balancing with Connector/J"
   and Section 8.3, "." As of Connector/J 5.1.12, this same
   implementation is used for balancing load between read-only
   slaves with ReplicationDriver.

   When trying to balance workload between multiple servers, the
   driver has to determine when it is safe to swap servers,
   doing so in the middle of a transaction, for example, could
   cause problems. It is important not to lose state
   information. For this reason, Connector/J will only try to
   pick a new server when one of the following happens:

    1. At transaction boundaries (transactions are explicitly
       committed or rolled back).

    2. A communication exception (SQL State starting with "08")
       is encountered.

    3. When a SQLException matches conditions defined by user,
       using the extension points defined by the
       loadBalanceSQLStateFailover,
       loadBalanceSQLExceptionSubclassFailover or
       loadBalanceExceptionChecker properties.

   The third condition revolves around three new properties
   introduced with Connector/J 5.1.13. It allows you to control
   which SQLExceptions trigger failover.

     * loadBalanceExceptionChecker - The
       loadBalanceExceptionChecker property is really the key.
       This takes a fully-qualified class name which implements
       the new com.mysql.jdbc.LoadBalanceExceptionChecker
       interface. This interface is very simple, and you only
       need to implement the following method:
public boolean shouldExceptionTriggerFailover(SQLException ex)

       A SQLException is passed in, and a boolean returned. A
       value of true triggers a failover, false does not.
       You can use this to implement your own custom logic. An
       example where this might be useful is when dealing with
       transient errors when using MySQL Cluster, where certain
       buffers may become overloaded. The following code snippet
       illustrates this:

public class NdbLoadBalanceExceptionChecker
 extends StandardLoadBalanceExceptionChecker {

 public boolean shouldExceptionTriggerFailover(SQLException ex) {
  return super.shouldExceptionTriggerFailover(ex)
    ||  checkNdbException(ex);
 }

 private boolean checkNdbException(SQLException ex){
 // Have to parse the message since most NDB errors
 // are mapped to the same DEMC.
  return (ex.getMessage().startsWith("Lock wait timeout exceeded") ||
  (ex.getMessage().startsWith("Got temporary error")
  && ex.getMessage().endsWith("from NDB")));
 }
}


       The code above extends
       com.mysql.jdbc.StandardLoadBalanceExceptionChecker, which
       is the default implementation. There are a few convenient
       shortcuts built into this, for those who want to have
       some level of control using properties, without writing
       Java code. This default implementation uses the two
       remaining properties: loadBalanceSQLStateFailover and
       loadBalanceSQLExceptionSubclassFailover.

     * loadBalanceSQLStateFailover - allows you to define a
       comma-delimited list of SQLState code prefixes, against
       which a SQLException is compared. If the prefix matches,
       failover is triggered. So, for example, the following
       would trigger a failover if a given SQLException starts
       with "00", or is "12345":
loadBalanceSQLStateFailover=00,12345


     * loadBalanceSQLExceptionSubclassFailover - can be used in
       conjunction with loadBalanceSQLStateFailover or on its
       own. If you want certain subclasses of SQLException to
       trigger failover, simply provide a comma-delimited list
       of fully-qualified class or interface names to check
       against. For example, if you want all
       SQLTransientConnectionExceptions to trigger failover, you
       would specify:
loadBalanceSQLExceptionSubclassFailover=java.sql.SQLTransientConnectio
nException

   While the three failover conditions enumerated earlier suit
   most situations, if autocommit is enabled, Connector/J never
   re-balances, and continues using the same physical
   connection. This can be problematic, particularly when
   load-balancing is being used to distribute read-only load
   across multiple slaves. However, Connector/J can be
   configured to re-balance after a certain number of statements
   are executed, when autocommit is enabled. This functionality
   is dependent upon the following properties:

     * loadBalanceAutoCommitStatementThreshold - defines the
       number of matching statements which will trigger the
       driver to potentially swap physical server connections.
       The default value, 0, retains the behavior that
       connections with autocommit enabled are never balanced.

     * loadBalanceAutoCommitStatementRegex - the regular
       expression against which statements must match. The
       default value, blank, matches all statements. So, for
       example, using the following properties will cause
       Connector/J to re-balance after every third statement
       that contains the string "test":
loadBalanceAutoCommitStatementThreshold=3
loadBalanceAutoCommitStatementRegex=.*test.*

       loadBalanceAutoCommitStatementRegex can prove useful in a
       number of situations. Your application may use temporary
       tables, server-side session state variables, or
       connection state, where letting the driver arbitrarily
       swap physical connections before processing is complete
       could cause data loss or other problems. This allows you
       to identify a trigger statement that is only executed
       when it is safe to swap physical connections.

Chapter 9 Using the Connector/J Interceptor Classes

   An interceptor is a software design pattern that provides a
   transparent way to extend or modify some aspect of a program,
   similar to a user exit. No recompiling is required. With
   Connector/J, the interceptors are enabled and disabled by
   updating the connection string to refer to different sets of
   interceptor classes that you instantiate.

   The connection properties that control the interceptors are
   explained in Section 5.1, "Driver/Datasource Class Names, URL
   Syntax and Configuration Properties for Connector/J:"

     * connectionLifecycleInterceptors, where you specify the
       fully qualified names of classes that implement the
       com.mysql.jdbc.ConnectionLifecycleInterceptor interface.
       In these kinds of interceptor classes, you might log
       events such as rollbacks, measure the time between
       transaction start and end, or count events such as calls
       to setAutoCommit().

     * exceptionInterceptors, where you specify the fully
       qualified names of classes that implement the
       com.mysql.jdbc.ExceptionInterceptor interface. In these
       kinds of interceptor classes, you might add extra
       diagnostic information to exceptions that can have
       multiple causes or indicate a problem with server
       settings. Because exceptionInterceptors classes are only
       called when handling a SQLException thrown from
       Connector/J code, they can be used even in production
       deployments without substantial performance overhead.

     * statementInterceptors, where you specify the fully
       qualified names of classes that implement the
       com.mysql.jdbc.StatementInterceptorV2 interface. In these
       kinds of interceptor classes, you might change or augment
       the processing done by certain kinds of statements, such
       as automatically checking for queried data in a memcached
       server, rewriting slow queries, logging information about
       statement execution, or route requests to remote servers.

Chapter 10 Using Connector/J with Tomcat

   The following instructions are based on the instructions for
   Tomcat-5.x, available at
   http://tomcat.apache.org/tomcat-5.5-doc/jndi-datasource-examp
   les-howto.html which is current at the time this document was
   written.

   First, install the .jar file that comes with Connector/J in
   $CATALINA_HOME/common/lib so that it is available to all
   applications installed in the container.

   Next, configure the JNDI DataSource by adding a declaration
   resource to $CATALINA_HOME/conf/server.xml in the context
   that defines your web application:
  <Context ....>

  ...

  <Resource name="jdbc/MySQLDB"
               auth="Container"
               type="javax.sql.DataSource"/>

  <ResourceParams name="jdbc/MySQLDB">
    <parameter>
      <name>factory</name>
      <value>org.apache.commons.dbcp.BasicDataSourceFactory</value>
    </parameter>

    <parameter>
      <name>maxActive</name>
      <value>10</value>
    </parameter>

    <parameter>
      <name>maxIdle</name>
      <value>5</value>
    </parameter>

    <parameter>
      <name>validationQuery</name>
      <value>SELECT 1</value>
    </parameter>

    <parameter>
      <name>testOnBorrow</name>
      <value>true</value>
    </parameter>

    <parameter>
      <name>testWhileIdle</name>
      <value>true</value>
    </parameter>

    <parameter>
      <name>timeBetweenEvictionRunsMillis</name>
      <value>10000</value>
    </parameter>

    <parameter>
      <name>minEvictableIdleTimeMillis</name>
      <value>60000</value>
    </parameter>

    <parameter>
     <name>username</name>
     <value>someuser</value>
    </parameter>

    <parameter>
     <name>password</name>
     <value>somepass</value>
    </parameter>

    <parameter>
       <name>driverClassName</name>
       <value>com.mysql.jdbc.Driver</value>
    </parameter>

    <parameter>
      <name>url</name>
      <value>jdbc:mysql://localhost:3306/test</value>
    </parameter>

  </ResourceParams>
</Context>

   Note that Connector/J 5.1.3 introduced a facility whereby,
   rather than use a validationQuery value of SELECT 1, it is
   possible to use validationQuery with a value set to /* ping
   */. This sends a ping to the server which then returns a fake
   result set. This is a lighter weight solution. It also has
   the advantage that if using ReplicationConnection or
   LoadBalancedConnection type connections, the ping will be
   sent across all active connections. The following XML snippet
   illustrates how to select this option:

<parameter>
 <name>validationQuery</name>
 <value>/* ping */</value>
</parameter>


   Note that /* ping */ has to be specified exactly.

   In general, follow the installation instructions that come
   with your version of Tomcat, as the way you configure
   datasources in Tomcat changes from time to time, and if you
   use the wrong syntax in your XML file, you will most likely
   end up with an exception similar to the following:
Error: java.sql.SQLException: Cannot load JDBC driver class 'null ' SQ
L
state: null

   Note that the auto-loading of drivers having the
   META-INF/service/java.sql.Driver class in JDBC 4.0 and above
   causes an improper undeployment of the Connector/J driver in
   Tomcat on Windows. Namely, the Connector/J jar remains
   locked. This is an initialization problem that is not related
   to the driver. The possible workarounds, if viable, are as
   follows: use "antiResourceLocking=true" as a Tomcat Context
   attribute, or remove the META-INF/ directory.

Chapter 11 Using Connector/J with JBoss

   These instructions cover JBoss-4.x. To make the JDBC driver
   classes available to the application server, copy the .jar
   file that comes with Connector/J to the lib directory for
   your server configuration (which is usually called default).
   Then, in the same configuration directory, in the
   subdirectory named deploy, create a datasource configuration
   file that ends with -ds.xml, which tells JBoss to deploy this
   file as a JDBC Datasource. The file should have the following
   contents:
<datasources>
    <local-tx-datasource>

        <jndi-name>MySQLDB</jndi-name>
        <connection-url>jdbc:mysql://localhost:3306/dbname</connection
-url>
        <driver-class>com.mysql.jdbc.Driver</driver-class>
        <user-name>user</user-name>
        <password>pass</password>

        <min-pool-size>5</min-pool-size>

        <max-pool-size>20</max-pool-size>

        <idle-timeout-minutes>5</idle-timeout-minutes>

        <exception-sorter-class-name>
  com.mysql.jdbc.integration.jboss.ExtendedMysqlExceptionSorter
        </exception-sorter-class-name>
        <valid-connection-checker-class-name>
  com.mysql.jdbc.integration.jboss.MysqlValidConnectionChecker
        </valid-connection-checker-class-name>

    </local-tx-datasource>
</datasources>

Chapter 12 Using Connector/J with Spring

   The Spring Framework is a Java-based application framework
   designed for assisting in application design by providing a
   way to configure components. The technique used by Spring is
   a well known design pattern called Dependency Injection (see
   Inversion of Control Containers and the Dependency Injection
   pattern
   (http://www.martinfowler.com/articles/injection.html)). This
   article will focus on Java-oriented access to MySQL databases
   with Spring 2.0. For those wondering, there is a .NET port of
   Spring appropriately named Spring.NET.

   Spring is not only a system for configuring components, but
   also includes support for aspect oriented programming (AOP).
   This is one of the main benefits and the foundation for
   Spring's resource and transaction management. Spring also
   provides utilities for integrating resource management with
   JDBC and Hibernate.

   For the examples in this section the MySQL world sample
   database will be used. The first task is to set up a MySQL
   data source through Spring. Components within Spring use the
   "bean" terminology. For example, to configure a connection to
   a MySQL server supporting the world sample database, you
   might use:

<util:map id="dbProps">
    <entry key="db.driver" value="com.mysql.jdbc.Driver"/>
    <entry key="db.jdbcurl" value="jdbc:mysql://localhost/world"/>
    <entry key="db.username" value="myuser"/>
    <entry key="db.password" value="mypass"/>
</util:map>


   In the above example, we are assigning values to properties
   that will be used in the configuration. For the datasource
   configuration:

<bean id="dataSource"
       class="org.springframework.jdbc.datasource.DriverManagerDataSou
rce">
    <property name="driverClassName" value="${db.driver}"/>
    <property name="url" value="${db.jdbcurl}"/>
    <property name="username" value="${db.username}"/>
    <property name="password" value="${db.password}"/>
</bean>


   The placeholders are used to provide values for properties of
   this bean. This means that you can specify all the properties
   of the configuration in one place instead of entering the
   values for each property on each bean. We do, however, need
   one more bean to pull this all together. The last bean is
   responsible for actually replacing the placeholders with the
   property values.

<bean
 class="org.springframework.beans.factory.config.PropertyPlaceholderCo
nfigurer">
    <property name="properties" ref="dbProps"/>
</bean>


   Now that we have our MySQL data source configured and ready
   to go, we write some Java code to access it. The example
   below will retrieve three random cities and their
   corresponding country using the data source we configured
   with Spring.
// Create a new application context. this processes the Spring config
ApplicationContext ctx =
    new ClassPathXmlApplicationContext("ex1appContext.xml");
// Retrieve the data source from the application context
    DataSource ds = (DataSource) ctx.getBean("dataSource");
// Open a database connection using Spring's DataSourceUtils
Connection c = DataSourceUtils.getConnection(ds);
try {
    // retrieve a list of three random cities
    PreparedStatement ps = c.prepareStatement(
        "select City.Name as 'City', Country.Name as 'Country' " +
        "from City inner join Country on City.CountryCode = Country.Co
de " +
        "order by rand() limit 3");
    ResultSet rs = ps.executeQuery();
    while(rs.next()) {
        String city = rs.getString("City");
        String country = rs.getString("Country");
        System.out.printf("The city %s is in %s%n", city, country);
    }
} catch (SQLException ex) {
    // something has failed and we print a stack trace to analyse the
error
    ex.printStackTrace();
    // ignore failure closing connection
    try { c.close(); } catch (SQLException e) { }
} finally {
    // properly release our connection
    DataSourceUtils.releaseConnection(c, ds);
}

   This is very similar to normal JDBC access to MySQL with the
   main difference being that we are using DataSourceUtils
   instead of the DriverManager to create the connection.

   While it may seem like a small difference, the implications
   are somewhat far reaching. Spring manages this resource in a
   way similar to a container managed data source in a J2EE
   application server. When a connection is opened, it can be
   subsequently accessed in other parts of the code if it is
   synchronized with a transaction. This makes it possible to
   treat different parts of your application as transactional
   instead of passing around a database connection.

12.1 Using JdbcTemplate

   Spring makes extensive use of the Template method design
   pattern (see Template Method Pattern
   (http://en.wikipedia.org/wiki/Template_method_pattern)). Our
   immediate focus will be on the JdbcTemplate and related
   classes, specifically NamedParameterJdbcTemplate. The
   template classes handle obtaining and releasing a connection
   for data access when one is needed.

   The next example shows how to use NamedParameterJdbcTemplate
   inside of a DAO (Data Access Object) class to retrieve a
   random city given a country code.
public class Ex2JdbcDao {
     /**

     * Data source reference which will be provided by Spring.
     */
     private DataSource dataSource;

     /**

     * Our query to find a random city given a country code. Notice

     * the ":country" parameter toward the end. This is called a

     * named parameter.
     */
     private String queryString = "select Name from City " +
        "where CountryCode = :country order by rand() limit 1";

     /**

     * Retrieve a random city using Spring JDBC access classes.
     */
     public String getRandomCityByCountryCode(String cntryCode) {
         // A template that permits using queries with named parameter
s
         NamedParameterJdbcTemplate template =
         new NamedParameterJdbcTemplate(dataSource);
         // A java.util.Map is used to provide values for the paramete
rs
         Map params = new HashMap();
         params.put("country", cntryCode);
         // We query for an Object and specify what class we are expec
ting
         return (String)template.queryForObject(queryString, params, S
tring.class);
     }

    /**

    * A JavaBean setter-style method to allow Spring to inject the dat
a source.

    * @param dataSource
    */
    public void setDataSource(DataSource dataSource) {
        this.dataSource = dataSource;
    }
}

   The focus in the above code is on the
   getRandomCityByCountryCode() method. We pass a country code
   and use the NamedParameterJdbcTemplate to query for a city.
   The country code is placed in a Map with the key "country",
   which is the parameter is named in the SQL query.

   To access this code, you need to configure it with Spring by
   providing a reference to the data source.

<bean id="dao" class="code.Ex2JdbcDao">
    <property name="dataSource" ref="dataSource"/>
</bean>


   At this point, we can just grab a reference to the DAO from
   Spring and call getRandomCityByCountryCode().
    // Create the application context
    ApplicationContext ctx =
    new ClassPathXmlApplicationContext("ex2appContext.xml");
    // Obtain a reference to our DAO
    Ex2JdbcDao dao = (Ex2JdbcDao) ctx.getBean("dao");

    String countryCode = "USA";

    // Find a few random cities in the US
    for(int i = 0; i < 4; ++i)
        System.out.printf("A random city in %s is %s%n", countryCode,
            dao.getRandomCityByCountryCode(countryCode));

   This example shows how to use Spring's JDBC classes to
   completely abstract away the use of traditional JDBC classes
   including Connection and PreparedStatement.

12.2 Transactional JDBC Access

   You might be wondering how we can add transactions into our
   code if we do not deal directly with the JDBC classes. Spring
   provides a transaction management package that not only
   replaces JDBC transaction management, but also enables
   declarative transaction management (configuration instead of
   code).

   To use transactional database access, we will need to change
   the storage engine of the tables in the world database. The
   downloaded script explicitly creates MyISAM tables which do
   not support transactional semantics. The InnoDB storage
   engine does support transactions and this is what we will be
   using. We can change the storage engine with the following
   statements.
ALTER TABLE City ENGINE=InnoDB;
ALTER TABLE Country ENGINE=InnoDB;
ALTER TABLE CountryLanguage ENGINE=InnoDB;

   A good programming practice emphasized by Spring is
   separating interfaces and implementations. What this means is
   that we can create a Java interface and only use the
   operations on this interface without any internal knowledge
   of what the actual implementation is. We will let Spring
   manage the implementation and with this it will manage the
   transactions for our implementation.

   First you create a simple interface:
public interface Ex3Dao {
    Integer createCity(String name, String countryCode,
    String district, Integer population);
}

   This interface contains one method that will create a new
   city record in the database and return the id of the new
   record. Next you need to create an implementation of this
   interface.
public class Ex3DaoImpl implements Ex3Dao {
    protected DataSource dataSource;
    protected SqlUpdate updateQuery;
    protected SqlFunction idQuery;

    public Integer createCity(String name, String countryCode,
        String district, Integer population) {
            updateQuery.update(new Object[] { name, countryCode,
                   district, population });
            return getLastId();
        }

    protected Integer getLastId() {
        return idQuery.run();
    }
}

   You can see that we only operate on abstract query objects
   here and do not deal directly with the JDBC API. Also, this
   is the complete implementation. All of our transaction
   management will be dealt with in the configuration. To get
   the configuration started, we need to create the DAO.

<bean id="dao" class="code.Ex3DaoImpl">
    <property name="dataSource" ref="dataSource"/>
    <property name="updateQuery">...</property>
    <property name="idQuery">...</property>
</bean>


   Now you need to set up the transaction configuration. The
   first thing you must do is create transaction manager to
   manage the data source and a specification of what
   transaction properties are required for the dao methods.

<bean id="transactionManager"
  class="org.springframework.jdbc.datasource.DataSourceTransactionMana
ger">
    <property name="dataSource" ref="dataSource"/>
</bean>

<tx:advice id="txAdvice" transaction-manager="transactionManager">
    <tx:attributes>
        <tx:method name="*"/>
    </tx:attributes>
</tx:advice>


   The preceding code creates a transaction manager that handles
   transactions for the data source provided to it. The txAdvice
   uses this transaction manager and the attributes specify to
   create a transaction for all methods. Finally you need to
   apply this advice with an AOP pointcut.

<aop:config>
    <aop:pointcut id="daoMethods"
        expression="execution(* code.Ex3Dao.*(..))"/>
     <aop:advisor advice-ref="txAdvice" pointcut-ref="daoMethods"/>
</aop:config>


   This basically says that all methods called on the Ex3Dao
   interface will be wrapped in a transaction. To make use of
   this, you only have to retrieve the dao from the application
   context and call a method on the dao instance.
Ex3Dao dao = (Ex3Dao) ctx.getBean("dao");
Integer id = dao.createCity(name,  countryCode, district, pop);

   We can verify from this that there is no transaction
   management happening in our Java code and it is all
   configured with Spring. This is a very powerful notion and
   regarded as one of the most beneficial features of Spring.

12.3 Connection Pooling with Spring

   In many situations, such as web applications, there will be a
   large number of small database transactions. When this is the
   case, it usually makes sense to create a pool of database
   connections available for web requests as needed. Although
   MySQL does not spawn an extra process when a connection is
   made, there is still a small amount of overhead to create and
   set up the connection. Pooling of connections also alleviates
   problems such as collecting large amounts of sockets in the
   TIME_WAIT state.

   Setting up pooling of MySQL connections with Spring is as
   simple as changing the data source configuration in the
   application context. There are a number of configurations
   that we can use. The first example is based on the Jakarta
   Commons DBCP library
   (http://jakarta.apache.org/commons/dbcp/). The example below
   replaces the source configuration that was based on
   DriverManagerDataSource with DBCP's BasicDataSource.

<bean id="dataSource" destroy-method="close"
  class="org.apache.commons.dbcp.BasicDataSource">
    <property name="driverClassName" value="${db.driver}"/>
    <property name="url" value="${db.jdbcurl}"/>
    <property name="username" value="${db.username}"/>
    <property name="password" value="${db.password}"/>
    <property name="initialSize" value="3"/>
</bean>


   The configuration of the two solutions is very similar. The
   difference is that DBCP will pool connections to the database
   instead of creating a new connection every time one is
   requested. We have also set a parameter here called
   initialSize. This tells DBCP that we want three connections
   in the pool when it is created.

   Another way to configure connection pooling is to configure a
   data source in our J2EE application server. Using JBoss as an
   example, you can set up the MySQL connection pool by creating
   a file called mysql-local-ds.xml and placing it in the
   server/default/deploy directory in JBoss. Once we have this
   setup, we can use JNDI to look it up. With Spring, this
   lookup is very simple. The data source configuration looks
   like this.

<jee:jndi-lookup id="dataSource" jndi-name="java:MySQL_DS"/>


Chapter 13 Using Connector/J with GlassFish

   This section explains how to use MySQL Connector/J with
   GlassFish (tm) Server Open Source Edition 3.0.1. GlassFish
   can be downloaded from the GlassFish website
   (https://glassfish.dev.java.net/public/downloadsindex.html#to
   p).

   Once GlassFish is installed, make sure it can access MySQL
   Connector/J. To do this, copy the MySQL Connector/J jar file
   to the domain-dir/lib directory. For example, copy
   mysql-connector-java-5.1.30-bin.jar to
   C:\glassfish-install-path\domains\domain-name\lib. Restart
   the GlassFish Application Server. For more information, see
   "Integrating the JDBC Driver" in GlassFish Server Open Source
   Edition Administration Guide, available at GlassFish Server
   Documentation
   (https://glassfish.java.net/documentation.html).

   You are now ready to create JDBC Connection Pools and JDBC
   Resources.

   Creating a Connection Pool

    1. In the GlassFish Administration Console, using the
       navigation tree navigate to Resources, JDBC, Connection
       Pools.

    2. In the JDBC Connection Pools frame click New. You will
       enter a two step wizard.

    3. In the Name field under General Settings enter the name
       for the connection pool, for example enter MySQLConnPool.

    4. In the Resource Type field, select javax.sql.DataSource
       from the drop-down listbox.

    5. In the Database Vendor field, select MySQL from the
       drop-down listbox. Click Next to go to the next page of
       the wizard.

    6. You can accept the default settings for General Settings,
       Pool Settings and Transactions for this example. Scroll
       down to Additional Properties.

    7. In Additional Properties you will need to ensure the
       following properties are set:

          + ServerName - The server to connect to. For local
            testing this will be localhost.

          + User - The user name with which to connect to MySQL.

          + Password - The corresponding password for the user.

          + DatabaseName - The database to connect to, for
            example the sample MySQL database World.

    8. Click Finish to exit the wizard. You will be taken to the
       JDBC Connection Pools page where all current connection
       pools, including the one you just created, will be
       displayed.

    9. In the JDBC Connection Pools frame click on the
       connection pool you just created. Here, you can review
       and edit information about the connection pool. Because
       Connector/J does not support optimized validation
       queries, go to the Advanced tab, and under Connection
       Validation, configure the following settings:

          + Connection Validation - select Required.

          + Validation Method - select table from the drop-down
            menu.

          + Table Name - enter DUAL.
   10. To test your connection pool click the Ping button at the
       top of the frame. A message will be displayed confirming
       correct operation or otherwise. If an error message is
       received recheck the previous steps, and ensure that
       MySQL Connector/J has been correctly copied into the
       previously specified location.

   Now that you have created a connection pool you will also
   need to create a JDBC Resource (data source) for use by your
   application.

   Creating a JDBC Resource

   Your Java application will usually reference a data source
   object to establish a connection with the database. This
   needs to be created first using the following procedure.

     * Using the navigation tree in the GlassFish Administration
       Console, navigate to Resources, JDBC, JDBC Resources. A
       list of resources will be displayed in the JDBC Resources
       frame.

     * Click New. The New JDBC Resource frame will be displayed.

     * In the JNDI Name field, enter the JNDI name that will be
       used to access this resource, for example enter
       jdbc/MySQLDataSource.

     * In the Pool Name field, select a connection pool you want
       this resource to use from the drop-down listbox.

     * Optionally, you can enter a description into the
       Description field.

     * Additional properties can be added if required.

     * Click OK to create the new JDBC resource. The JDBC
       Resources frame will list all available JDBC Resources.

13.1 A Simple JSP Application with GlassFish, Connector/J and MySQL

   This section shows how to deploy a simple JSP application on
   GlassFish, that connects to a MySQL database.

   This example assumes you have already set up a suitable
   Connection Pool and JDBC Resource, as explained in the
   preceding sections. It is also assumed you have a sample
   database installed, such as world.

   The main application code, index.jsp is presented here:

<%@ page import="java.sql.*, javax.sql.*, java.io.*, javax.naming.*" %
>
<html>
<head><title>Hello world from JSP</title></head>
<body>
<%
  InitialContext ctx;
  DataSource ds;
  Connection conn;
  Statement stmt;
  ResultSet rs;

  try {
    ctx = new InitialContext();
    ds = (DataSource) ctx.lookup("java:comp/env/jdbc/MySQLDataSource")
;
    //ds = (DataSource) ctx.lookup("jdbc/MySQLDataSource");
    conn = ds.getConnection();
    stmt = conn.createStatement();
    rs = stmt.executeQuery("SELECT * FROM Country");

    while(rs.next()) {
%>
    <h3>Name: <%= rs.getString("Name") %></h3>
    <h3>Population: <%= rs.getString("Population") %></h3>
<%
    }
  }
  catch (SQLException se) {
%>
    <%= se.getMessage() %>
<%
  }
  catch (NamingException ne) {
%>
    <%= ne.getMessage() %>
<%
  }
%>
</body>
</html>


   In addition two XML files are required: web.xml, and
   sun-web.xml. There may be other files present, such as
   classes and images. These files are organized into the
   directory structure as follows:
index.jsp
WEB-INF
   |
   - web.xml
   - sun-web.xml

   The code for web.xml is:

<?xml version="1.0" encoding="UTF-8"?>
<web-app version="2.4" xmlns="http://java.sun.com/xml/ns/j2ee" xmlns:x
si="http://www.w3.org/2001/XMLSchema-instance" xsi:schemaLocation="htt
p://java.sun.com/xml/ns/j2ee http://java.sun.com/xml/ns/j2ee/web-app_2
_4.xsd">
  <display-name>HelloWebApp</display-name>
  <distributable/>
  <resource-ref>
    <res-ref-name>jdbc/MySQLDataSource</res-ref-name>
    <res-type>javax.sql.DataSource</res-type>
    <res-auth>Container</res-auth>
    <res-sharing-scope>Shareable</res-sharing-scope>
  </resource-ref>
</web-app>


   The code for sun-web.xml is:

<?xml version="1.0" encoding="UTF-8"?>
<!DOCTYPE sun-web-app PUBLIC "-//Sun Microsystems, Inc.//DTD Applicati
on Server 8.1 Servlet 2.4//EN" "http://www.sun.com/software/appserver/
dtds/sun-web-app_2_4-1.dtd">
<sun-web-app>
  <context-root>HelloWebApp</context-root>
  <resource-ref>
    <res-ref-name>jdbc/MySQLDataSource</res-ref-name>
    <jndi-name>jdbc/MySQLDataSource</jndi-name>
  </resource-ref>
</sun-web-app>


   These XML files illustrate a very important aspect of running
   JDBC applications on GlassFish. On GlassFish it is important
   to map the string specified for a JDBC resource to its JNDI
   name, as set up in the GlassFish administration console. In
   this example, the JNDI name for the JDBC resource, as
   specified in the GlassFish Administration console when
   creating the JDBC Resource, was jdbc/MySQLDataSource. This
   must be mapped to the name given in the application. In this
   example the name specified in the application,
   jdbc/MySQLDataSource, and the JNDI name, happen to be the
   same, but this does not necessarily have to be the case. Note
   that the XML element <res-ref-name> is used to specify the
   name as used in the application source code, and this is
   mapped to the JNDI name specified using the <jndi-name>
   element, in the file sun-web.xml. The resource also has to be
   created in the web.xml file, although the mapping of the
   resource to a JNDI name takes place in the sun-web.xml file.

   If you do not have this mapping set up correctly in the XML
   files you will not be able to lookup the data source using a
   JNDI lookup string such as:
ds = (DataSource) ctx.lookup("java:comp/env/jdbc/MySQLDataSource");

   You will still be able to access the data source directly
   using:
ds = (DataSource) ctx.lookup("jdbc/MySQLDataSource");

   With the source files in place, in the correct directory
   structure, you are ready to deploy the application:

    1. In the navigation tree, navigate to Applications - the
       Applications frame will be displayed. Click Deploy.

    2. You can now deploy an application packaged into a single
       WAR file from a remote client, or you can choose a
       packaged file or directory that is locally accessible to
       the server. If you are simply testing an application
       locally you can simply point GlassFish at the directory
       that contains your application, without needing to
       package the application into a WAR file.

    3. Now select the application type from the Type drop-down
       listbox, which in this example is Web application.

    4. Click OK.

   Now, when you navigate to the Applications frame, you will
   have the option to Launch, Redeploy, or Restart your
   application. You can test your application by clicking
   Launch. The application will connection to the MySQL database
   and display the Name and Population of countries in the
   Country table.

13.2 A Simple Servlet with GlassFish, Connector/J and MySQL

   This section describes a simple servlet that can be used in
   the GlassFish environment to access a MySQL database. As with
   the previous section, this example assumes the sample
   database world is installed.

   The project is set up with the following directory structure:
index.html
WEB-INF
   |
   - web.xml
   - sun-web.xml
   - classes
        |
        - HelloWebServlet.java
        - HelloWebServlet.class

   The code for the servlet, located in HelloWebServlet.java, is
   as follows:

import javax.servlet.http.*;
import javax.servlet.*;
import java.io.*;
import java.sql.*;
import javax.sql.*;
import javax.naming.*;

public class HelloWebServlet extends HttpServlet {

  InitialContext ctx = null;
  DataSource ds = null;
  Connection conn = null;
  PreparedStatement ps = null;
  ResultSet rs = null;

  String sql = "SELECT Name, Population FROM Country WHERE Name=?";

  public void init () throws ServletException {
    try {
      ctx = new InitialContext();
      ds = (DataSource) ctx.lookup("java:comp/env/jdbc/MySQLDataSource
");
      conn = ds.getConnection();
      ps = conn.prepareStatement(sql);
    }
    catch (SQLException se) {
      System.out.println("SQLException: "+se.getMessage());
    }
    catch (NamingException ne) {
      System.out.println("NamingException: "+ne.getMessage());
    }
  }

  public void destroy () {
    try {
      if (rs != null)
        rs.close();
      if (ps != null)
        ps.close();
      if (conn != null)
        conn.close();
      if (ctx != null)
        ctx.close();
    }
    catch (SQLException se) {
      System.out.println("SQLException: "+se.getMessage());
    }
    catch (NamingException ne) {
      System.out.println("NamingException: "+ne.getMessage());
    }
  }

  public void doPost(HttpServletRequest req, HttpServletResponse resp)
{
    try {
      String country_name = req.getParameter("country_name");
      resp.setContentType("text/html");
      PrintWriter writer = resp.getWriter();
      writer.println("<html><body>");
      writer.println("<p>Country: "+country_name+"</p>");
      ps.setString(1, country_name);
      rs = ps.executeQuery();
      if (!rs.next()){
        writer.println("<p>Country does not exist!</p>");
      }
      else {
        rs.beforeFirst();
        while(rs.next()) {
          writer.println("<p>Name: "+rs.getString("Name")+"</p>");
          writer.println("<p>Population: "+rs.getString("Population")+
"</p>");
        }
      }
      writer.println("</body></html>");
      writer.close();
    }
    catch (Exception e) {
      e.printStackTrace();
    }
  }

  public void doGet(HttpServletRequest req, HttpServletResponse resp){
    try {
      resp.setContentType("text/html");
      PrintWriter writer = resp.getWriter();
      writer.println("<html><body>");
      writer.println("<p>Hello from servlet doGet()</p>");
      writer.println("</body></html>");
      writer.close();
    }
    catch (Exception e) {
      e.printStackTrace();
    }
  }
}


   In the preceding code a basic doGet() method is implemented,
   but is not used in the example. The code to establish the
   connection with the database is as shown in the previous
   example, Section 13.1, "A Simple JSP Application with
   GlassFish, Connector/J and MySQL," and is most conveniently
   located in the servlet init() method. The corresponding
   freeing of resources is located in the destroy method. The
   main functionality of the servlet is located in the doPost()
   method. If the user enters into the input form a country name
   that can be located in the database, the population of the
   country is returned. The code is invoked using a POST action
   associated with the input form. The form is defined in the
   file index.html:

<html>
  <head><title>HelloWebServlet</title></head>

  <body>
    <h1>HelloWebServlet</h1>

    <p>Please enter country name:</p>

    <form action="HelloWebServlet" method="POST">
      <input type="text" name="country_name" length="50" />
      <input type="submit" value="Submit" />
    </form>

  </body>
</html>


   The XML files web.xml and sun-web.xml are as for the example
   in the preceding section, Section 13.1, "A Simple JSP
   Application with GlassFish, Connector/J and MySQL," no
   additional changes are required.

   When compiling the Java source code, you will need to specify
   the path to the file javaee.jar. On Windows, this can be done
   as follows:
shell> javac -classpath c:\glassfishv3\glassfish\lib\javaee.jar HelloW
ebServlet.java

   Once the code is correctly located within its directory
   structure, and compiled, the application can be deployed in
   GlassFish. This is done in exactly the same way as described
   in the preceding section, Section 13.1, "A Simple JSP
   Application with GlassFish, Connector/J and MySQL."

   Once deployed the application can be launched from within the
   GlassFish Administration Console. Enter a country name such
   as "England", and the application will return "Country does
   not exist!". Enter "France", and the application will return
   a population of 59225700.

Chapter 14 Using Connector/J with MySQL Fabric

   MySQL Fabric is a system for managing a farm of MySQL servers
   (and other components). Fabric provides an extensible and
   easy to use system for managing a MySQL deployment for
   sharding and high-availability.

   For more information on MySQL Fabric, see MySQL Fabric
   (http://dev.mysql.com/doc/mysql-utilities/1.5/en/fabric.html)
   . For instructions on how to use Connector/J with MySQL
   Fabric, see Using Connector/J with MySQL Fabric
   (http://dev.mysql.com/doc/mysql-utilities/1.5/en/connector-j-
   fabric.html).

Chapter 15 Troubleshooting Connector/J Applications

   This section explains the symptoms and resolutions for the
   most commonly encountered issues with applications using
   MySQL Connector/J.

   Questions

     * 15.1: When I try to connect to the database with MySQL
       Connector/J, I get the following exception:
SQLException: Server configuration denies access to data source
SQLState: 08001
VendorError: 0

       What is going on? I can connect just fine with the MySQL
       command-line client.

     * 15.2: My application throws an SQLException 'No Suitable
       Driver'. Why is this happening?

     * 15.3: I'm trying to use MySQL Connector/J in an applet or
       application and I get an exception similar to:
SQLException: Cannot connect to MySQL server on host:3306.
Is there a MySQL server running on the machine/port you
are trying to connect to?

(java.security.AccessControlException)
SQLState: 08S01
VendorError: 0


     * 15.4: I have a servlet/application that works fine for a
       day, and then stops working overnight

     * 15.5: I'm trying to use JDBC 2.0 updatable result sets,
       and I get an exception saying my result set is not
       updatable.

     * 15.6: I cannot connect to the MySQL server using
       Connector/J, and I'm sure the connection parameters are
       correct.

     * 15.7: I am trying to connect to my MySQL server within my
       application, but I get the following error and stack
       trace:
java.net.SocketException
MESSAGE: Software caused connection abort: recv failed

STACKTRACE:

java.net.SocketException: Software caused connection abort: recv faile
d
at java.net.SocketInputStream.socketRead0(Native Method)
at java.net.SocketInputStream.read(Unknown Source)
at com.mysql.jdbc.MysqlIO.readFully(MysqlIO.java:1392)
at com.mysql.jdbc.MysqlIO.readPacket(MysqlIO.java:1414)
at com.mysql.jdbc.MysqlIO.doHandshake(MysqlIO.java:625)
at com.mysql.jdbc.Connection.createNewIO(Connection.java:1926)
at com.mysql.jdbc.Connection.<init>(Connection.java:452)
at com.mysql.jdbc.NonRegisteringDriver.connect(NonRegisteringDriver.ja
va:411)


     * 15.8: My application is deployed through JBoss and I am
       using transactions to handle the statements on the MySQL
       database. Under heavy loads, I am getting an error and
       stack trace, but these only occur after a fixed period of
       heavy activity.

     * 15.9: When using gcj, a java.io.CharConversionException
       exception is raised when working with certain character
       sequences.

     * 15.10: Updating a table that contains a primary key
       (http://dev.mysql.com/doc/refman/5.7/en/glossary.html#glo
       s_primary_key) that is either FLOAT
       (http://dev.mysql.com/doc/refman/5.7/en/floating-point-ty
       pes.html) or compound primary key that uses FLOAT
       (http://dev.mysql.com/doc/refman/5.7/en/floating-point-ty
       pes.html) fails to update the table and raises an
       exception.

     * 15.11: You get an ER_NET_PACKET_TOO_LARGE
       (http://dev.mysql.com/doc/refman/5.7/en/error-messages-se
       rver.html#error_er_net_packet_too_large) exception, even
       though the binary blob size you want to insert using JDBC
       is safely below the max_allowed_packet
       (http://dev.mysql.com/doc/refman/5.7/en/server-system-var
       iables.html#sysvar_max_allowed_packet) size.

     * 15.12: What should you do if you receive error messages
       similar to the following: "Communications link failure -
       Last packet sent to the server was X ms ago"?

     * 15.13: Why does Connector/J not reconnect to MySQL and
       re-issue the statement after a communication failure,
       instead of throwing an Exception, even though I use the
       autoReconnect connection string option?

     * 15.14: How can I use 3-byte UTF8 with Connector/J?

     * 15.15: How can I use 4-byte UTF8, utf8mb4 with
       Connector/J?

     * 15.16: Using useServerPrepStmts=false and certain
       character encodings can lead to corruption when inserting
       BLOBs. How can this be avoided?

   Questions and Answers

   15.1: When I try to connect to the database with MySQL
   Connector/J, I get the following exception:
SQLException: Server configuration denies access to data source
SQLState: 08001
VendorError: 0

   What is going on? I can connect just fine with the MySQL
   command-line client.

   MySQL Connector/J must use TCP/IP sockets to connect to
   MySQL, as Java does not support Unix Domain Sockets.
   Therefore, when MySQL Connector/J connects to MySQL, the
   security manager in MySQL server will use its grant tables to
   determine whether the connection is permitted.

   You must add the necessary security credentials to the MySQL
   server for this to happen, using the GRANT
   (http://dev.mysql.com/doc/refman/5.7/en/grant.html) statement
   to your MySQL Server. See GRANT Syntax
   (http://dev.mysql.com/doc/refman/5.7/en/grant.html), for more
   information.
   Note

   Testing your connectivity with the mysql command-line client
   will not work unless you add the "host" flag, and use
   something other than localhost for the host. The mysql
   command-line client will use Unix domain sockets if you use
   the special host name localhost. If you are testing
   connectivity to localhost, use 127.0.0.1 as the host name
   instead.
   Warning

   Changing privileges and permissions improperly in MySQL can
   potentially cause your server installation to not have
   optimal security properties.

   15.2: My application throws an SQLException 'No Suitable
   Driver'. Why is this happening?

   There are three possible causes for this error:

     * The Connector/J driver is not in your CLASSPATH, see
       Chapter 3, "Connector/J Installation."

     * The format of your connection URL is incorrect, or you
       are referencing the wrong JDBC driver.

     * When using DriverManager, the jdbc.drivers system
       property has not been populated with the location of the
       Connector/J driver.

   15.3: I'm trying to use MySQL Connector/J in an applet or
   application and I get an exception similar to:
SQLException: Cannot connect to MySQL server on host:3306.
Is there a MySQL server running on the machine/port you
are trying to connect to?

(java.security.AccessControlException)
SQLState: 08S01
VendorError: 0

   Either you're running an Applet, your MySQL server has been
   installed with the "skip-networking" option set, or your
   MySQL server has a firewall sitting in front of it.

   Applets can only make network connections back to the machine
   that runs the web server that served the .class files for the
   applet. This means that MySQL must run on the same machine
   (or you must have some sort of port re-direction) for this to
   work. This also means that you will not be able to test
   applets from your local file system, you must always deploy
   them to a web server.

   MySQL Connector/J can only communicate with MySQL using
   TCP/IP, as Java does not support Unix domain sockets. TCP/IP
   communication with MySQL might be affected if MySQL was
   started with the "skip-networking" flag, or if it is
   firewalled.

   If MySQL has been started with the "skip-networking" option
   set (the Debian Linux package of MySQL server does this for
   example), you need to comment it out in the file
   /etc/mysql/my.cnf or /etc/my.cnf. Of course your my.cnf file
   might also exist in the data directory of your MySQL server,
   or anywhere else (depending on how MySQL was compiled for
   your system). Binaries created by us always look in
   /etc/my.cnf and datadir/my.cnf. If your MySQL server has been
   firewalled, you will need to have the firewall configured to
   allow TCP/IP connections from the host where your Java code
   is running to the MySQL server on the port that MySQL is
   listening to (by default, 3306).

   15.4: I have a servlet/application that works fine for a day,
   and then stops working overnight

   MySQL closes connections after 8 hours of inactivity. You
   either need to use a connection pool that handles stale
   connections or use the autoReconnect parameter (see Section
   5.1, "Driver/Datasource Class Names, URL Syntax and
   Configuration Properties for Connector/J").

   Also, catch SQLExceptions in your application and deal with
   them, rather than propagating them all the way until your
   application exits. This is just good programming practice.
   MySQL Connector/J will set the SQLState (see
   java.sql.SQLException.getSQLState() in your API docs) to
   08S01 when it encounters network-connectivity issues during
   the processing of a query. Attempt to reconnect to MySQL at
   this point.

   The following (simplistic) example shows what code that can
   handle these exceptions might look like:

   Example 15.1 Connector/J: Example of transaction with retry
   logic
public void doBusinessOp() throws SQLException {
    Connection conn = null;
    Statement stmt = null;
    ResultSet rs = null;

    //
    // How many times do you want to retry the transaction
    // (or at least _getting_ a connection)?
    //
    int retryCount = 5;

    boolean transactionCompleted = false;

    do {
        try {
            conn = getConnection(); // assume getting this from a
                                    // javax.sql.DataSource, or the
                                    // java.sql.DriverManager

            conn.setAutoCommit(false);

            //
            // Okay, at this point, the 'retry-ability' of the
            // transaction really depends on your application logic,
            // whether or not you're using autocommit (in this case
            // not), and whether you're using transactional storage
            // engines
            //
            // For this example, we'll assume that it's _not_ safe
            // to retry the entire transaction, so we set retry
            // count to 0 at this point
            //
            // If you were using exclusively transaction-safe tables,
            // or your application could recover from a connection goi
ng
            // bad in the middle of an operation, then you would not
            // touch 'retryCount' here, and just let the loop repeat
            // until retryCount == 0.
            //
            retryCount = 0;

            stmt = conn.createStatement();

            String query = "SELECT foo FROM bar ORDER BY baz";

            rs = stmt.executeQuery(query);

            while (rs.next()) {
            }

            rs.close();
            rs = null;

            stmt.close();
            stmt = null;

            conn.commit();
            conn.close();
            conn = null;

            transactionCompleted = true;
        } catch (SQLException sqlEx) {

            //
            // The two SQL states that are 'retry-able' are 08S01
            // for a communications error, and 40001 for deadlock.
            //
            // Only retry if the error was due to a stale connection,
            // communications problem or deadlock
            //

            String sqlState = sqlEx.getSQLState();

            if ("08S01".equals(sqlState) || "40001".equals(sqlState))
{
                retryCount -= 1;
            } else {
                retryCount = 0;
            }
        } finally {
            if (rs != null) {
                try {
                    rs.close();
                } catch (SQLException sqlEx) {
                    // You'd probably want to log this...
                }
            }

            if (stmt != null) {
                try {
                    stmt.close();
                } catch (SQLException sqlEx) {
                    // You'd probably want to log this as well...
                }
            }

            if (conn != null) {
                try {
                    //
                    // If we got here, and conn is not null, the
                    // transaction should be rolled back, as not
                    // all work has been done

                    try {
                        conn.rollback();
                    } finally {
                        conn.close();
                    }
                } catch (SQLException sqlEx) {
                    //
                    // If we got an exception here, something
                    // pretty serious is going on, so we better
                    // pass it up the stack, rather than just
                    // logging it...

                    throw sqlEx;
                }
            }
        }
    } while (!transactionCompleted && (retryCount > 0));
}

   Note

   Use of the autoReconnect option is not recommended because
   there is no safe method of reconnecting to the MySQL server
   without risking some corruption of the connection state or
   database state information. Instead, use a connection pool,
   which will enable your application to connect to the MySQL
   server using an available connection from the pool. The
   autoReconnect facility is deprecated, and may be removed in a
   future release.

   15.5: I'm trying to use JDBC 2.0 updatable result sets, and I
   get an exception saying my result set is not updatable.

   Because MySQL does not have row identifiers, MySQL
   Connector/J can only update result sets that have come from
   queries on tables that have at least one primary key
   (http://dev.mysql.com/doc/refman/5.7/en/glossary.html#glos_pr
   imary_key), the query must select every primary key column,
   and the query can only span one table (that is, no joins).
   This is outlined in the JDBC specification.

   Note that this issue only occurs when using updatable result
   sets, and is caused because Connector/J is unable to
   guarantee that it can identify the correct rows within the
   result set to be updated without having a unique reference to
   each row. There is no requirement to have a unique field on a
   table if you are using UPDATE
   (http://dev.mysql.com/doc/refman/5.7/en/update.html) or
   DELETE (http://dev.mysql.com/doc/refman/5.7/en/delete.html)
   statements on a table where you can individually specify the
   criteria to be matched using a WHERE clause.

   15.6: I cannot connect to the MySQL server using Connector/J,
   and I'm sure the connection parameters are correct.

   Make sure that the skip-networking
   (http://dev.mysql.com/doc/refman/5.7/en/server-options.html#o
   ption_mysqld_skip-networking) option has not been enabled on
   your server. Connector/J must be able to communicate with
   your server over TCP/IP; named sockets are not supported.
   Also ensure that you are not filtering connections through a
   firewall or other network security system. For more
   information, see Can't connect to [local] MySQL server
   (http://dev.mysql.com/doc/refman/5.7/en/can-not-connect-to-se
   rver.html).

   15.7: I am trying to connect to my MySQL server within my
   application, but I get the following error and stack trace:
java.net.SocketException
MESSAGE: Software caused connection abort: recv failed

STACKTRACE:

java.net.SocketException: Software caused connection abort: recv faile
d
at java.net.SocketInputStream.socketRead0(Native Method)
at java.net.SocketInputStream.read(Unknown Source)
at com.mysql.jdbc.MysqlIO.readFully(MysqlIO.java:1392)
at com.mysql.jdbc.MysqlIO.readPacket(MysqlIO.java:1414)
at com.mysql.jdbc.MysqlIO.doHandshake(MysqlIO.java:625)
at com.mysql.jdbc.Connection.createNewIO(Connection.java:1926)
at com.mysql.jdbc.Connection.<init>(Connection.java:452)
at com.mysql.jdbc.NonRegisteringDriver.connect(NonRegisteringDriver.ja
va:411)

   The error probably indicates that you are using a older
   version of the Connector/J JDBC driver (2.0.14 or 3.0.x) and
   you are trying to connect to a MySQL server with version 4.1x
   or newer. The older drivers are not compatible with 4.1 or
   newer of MySQL as they do not support the newer
   authentication mechanisms.

   It is likely that the older version of the Connector/J driver
   exists within your application directory or your CLASSPATH
   includes the older Connector/J package.

   15.8: My application is deployed through JBoss and I am using
   transactions to handle the statements on the MySQL database.
   Under heavy loads, I am getting an error and stack trace, but
   these only occur after a fixed period of heavy activity.

   This is a JBoss, not Connector/J, issue and is connected to
   the use of transactions. Under heavy loads the time taken for
   transactions to complete can increase, and the error is
   caused because you have exceeded the predefined timeout.

   You can increase the timeout value by setting the
   TransactionTimeout attribute to the TransactionManagerService
   within the /conf/jboss-service.xml file (pre-4.0.3) or
   /deploy/jta-service.xml for JBoss 4.0.3 or later. See
   TransactionTimeout
   (http://wiki.jboss.org/wiki/Wiki.jsp?page=TransactionTimeout)
   within the JBoss wiki for more information.

   15.9: When using gcj, a java.io.CharConversionException
   exception is raised when working with certain character
   sequences.

   This is a known issue with gcj which raises an exception when
   it reaches an unknown character or one it cannot convert. Add
   useJvmCharsetConverters=true to your connection string to
   force character conversion outside of the gcj libraries, or
   try a different JDK.

   15.10: Updating a table that contains a primary key
   (http://dev.mysql.com/doc/refman/5.7/en/glossary.html#glos_pr
   imary_key) that is either FLOAT
   (http://dev.mysql.com/doc/refman/5.7/en/floating-point-types.
   html) or compound primary key that uses FLOAT
   (http://dev.mysql.com/doc/refman/5.7/en/floating-point-types.
   html) fails to update the table and raises an exception.

   Connector/J adds conditions to the WHERE clause during an
   UPDATE (http://dev.mysql.com/doc/refman/5.7/en/update.html)
   to check the old values of the primary key. If there is no
   match, then Connector/J considers this a failure condition
   and raises an exception.

   The problem is that rounding differences between supplied
   values and the values stored in the database may mean that
   the values never match, and hence the update fails. The issue
   will affect all queries, not just those from Connector/J.

   To prevent this issue, use a primary key that does not use
   FLOAT
   (http://dev.mysql.com/doc/refman/5.7/en/floating-point-types.
   html). If you have to use a floating point column in your
   primary key, use DOUBLE
   (http://dev.mysql.com/doc/refman/5.7/en/floating-point-types.
   html) or DECIMAL
   (http://dev.mysql.com/doc/refman/5.7/en/fixed-point-types.htm
   l) types in place of FLOAT
   (http://dev.mysql.com/doc/refman/5.7/en/floating-point-types.
   html).

   15.11: You get an ER_NET_PACKET_TOO_LARGE
   (http://dev.mysql.com/doc/refman/5.7/en/error-messages-server
   .html#error_er_net_packet_too_large) exception, even though
   the binary blob size you want to insert using JDBC is safely
   below the max_allowed_packet
   (http://dev.mysql.com/doc/refman/5.7/en/server-system-variabl
   es.html#sysvar_max_allowed_packet) size.

   This is because the hexEscapeBlock() method in
   com.mysql.jdbc.PreparedStatement.streamToBytes() may almost
   double the size of your data.

   15.12: What should you do if you receive error messages
   similar to the following: "Communications link failure - Last
   packet sent to the server was X ms ago"?

   Generally speaking, this error suggests that the network
   connection has been closed. There can be several root causes:

     * Firewalls or routers may clamp down on idle connections
       (the MySQL client/server protocol does not ping).

     * The MySQL Server may be closing idle connections that
       exceed the wait_timeout or interactive_timeout threshold.

   To help troubleshoot these issues, the following tips can be
   used. If a recent (5.1.13+) version of Connector/J is used,
   you will see an improved level of information compared to
   earlier versions. Older versions simply display the last time
   a packet was sent to the server, which is frequently 0 ms
   ago. This is of limited use, as it may be that a packet was
   just sent, while a packet from the server has not been
   received for several hours. Knowing the period of time since
   Connector/J last received a packet from the server is useful
   information, so if this is not displayed in your exception
   message, it is recommended that you update Connector/J.

   Further, if the time a packet was last sent/received exceeds
   the wait_timeout or interactive_timeout threshold, this is
   noted in the exception message.

   Although network connections can be volatile, the following
   can be helpful in avoiding problems:

     * Ensure connections are valid when used from the
       connection pool. Use a query that starts with /* ping */
       to execute a lightweight ping instead of full query.
       Note, the syntax of the ping needs to be exactly as
       specified here.

     * Minimize the duration a connection object is left idle
       while other application logic is executed.

     * Explicitly validate the connection before using it if the
       connection has been left idle for an extended period of
       time.

     * Ensure that wait_timeout and interactive_timeout are set
       sufficiently high.

     * Ensure that tcpKeepalive is enabled.

     * Ensure that any configurable firewall or router timeout
       settings allow for the maximum expected connection idle
       time.

   Note

   Do not expect to be able to reuse a connection without
   problems, if it has being lying idle for a period. If a
   connection is to be reused after being idle for any length of
   time, ensure that you explicitly test it before reusing it.

   15.13: Why does Connector/J not reconnect to MySQL and
   re-issue the statement after a communication failure, instead
   of throwing an Exception, even though I use the autoReconnect
   connection string option?

   There are several reasons for this. The first is
   transactional integrity. The MySQL Reference Manual states
   that "there is no safe method of reconnecting to the MySQL
   server without risking some corruption of the connection
   state or database state information". Consider the following
   series of statements for example:

conn.createStatement().execute(
  "UPDATE checking_account SET balance = balance - 1000.00 WHERE custo
mer='Smith'");
conn.createStatement().execute(
  "UPDATE savings_account SET balance = balance + 1000.00 WHERE custom
er='Smith'");
conn.commit();


   Consider the case where the connection to the server fails
   after the UPDATE to checking_account. If no exception is
   thrown, and the application never learns about the problem,
   it will continue executing. However, the server did not
   commit the first transaction in this case, so that will get
   rolled back. But execution continues with the next
   transaction, and increases the savings_account balance by
   1000. The application did not receive an exception, so it
   continued regardless, eventually committing the second
   transaction, as the commit only applies to the changes made
   in the new connection. Rather than a transfer taking place, a
   deposit was made in this example.

   Note that running with autocommit enabled does not solve this
   problem. When Connector/J encounters a communication problem,
   there is no means to determine whether the server processed
   the currently executing statement or not. The following
   theoretical states are equally possible:

     * The server never received the statement, and therefore no
       related processing occurred on the server.

     * The server received the statement, executed it in full,
       but the response was not received by the client.

   If you are running with autocommit enabled, it is not
   possible to guarantee the state of data on the server when a
   communication exception is encountered. The statement may
   have reached the server, or it may not. All you know is that
   communication failed at some point, before the client
   received confirmation (or data) from the server. This does
   not only affect autocommit statements though. If the
   communication problem occurred during Connection.commit(),
   the question arises of whether the transaction was committed
   on the server before the communication failed, or whether the
   server received the commit request at all.

   The second reason for the generation of exceptions is that
   transaction-scoped contextual data may be vulnerable, for
   example:

     * Temporary tables.

     * User-defined variables.

     * Server-side prepared statements.

   These items are lost when a connection fails, and if the
   connection silently reconnects without generating an
   exception, this could be detrimental to the correct execution
   of your application.

   In summary, communication errors generate conditions that may
   well be unsafe for Connector/J to simply ignore by silently
   reconnecting. It is necessary for the application to be
   notified. It is then for the application developer to decide
   how to proceed in the event of connection errors and
   failures.

   15.14: How can I use 3-byte UTF8 with Connector/J?

   To use 3-byte UTF8 with Connector/J set
   characterEncoding=utf8 and set useUnicode=true in the
   connection string.

   15.15: How can I use 4-byte UTF8, utf8mb4 with Connector/J?

   To use 4-byte UTF8 with Connector/J configure the MySQL
   server with character_set_server=utf8mb4. Connector/J will
   then use that setting as long as characterEncoding has not
   been set in the connection string. This is equivalent to
   autodetection of the character set.

   15.16: Using useServerPrepStmts=false and certain character
   encodings can lead to corruption when inserting BLOBs. How
   can this be avoided?

   When using certain character encodings, such as SJIS, CP932,
   and BIG5, it is possible that BLOB data contains characters
   that can be interpreted as control characters, for example,
   backslash, '\'. This can lead to corrupted data when
   inserting BLOBs into the database. There are two things that
   need to be done to avoid this:

    1. Set the connection string option useServerPrepStmts to
       true.

    2. Set SQL_MODE to NO_BACKSLASH_ESCAPES.

Chapter 16 Known Issues and Limitations

   The following are some known issues and limitations for MySQL
   Connector/J:

     * When Connector/J retrieves timestamps for a daylight
       saving time (DST) switch day using the getTimeStamp()
       method on the result set, some of the returned values
       might be wrong. The errors can be avoided by using the
       following connection options when connecting to a
       database:
        useTimezone=true
        useLegacyDatetimeCode=false
        serverTimezone=UTC

Chapter 17 Connector/J Support

17.1 Connector/J Community Support

   Oracle provides assistance to the user community by means of
   its mailing lists. For Connector/J related issues, you can
   get help from experienced users by using the MySQL and Java
   mailing list. Archives and subscription information is
   available online at http://lists.mysql.com/java.

   For information about subscribing to MySQL mailing lists or
   to browse list archives, visit http://lists.mysql.com/. See
   MySQL Mailing Lists
   (http://dev.mysql.com/doc/refman/5.7/en/mailing-lists.html).

   Community support from experienced users is also available
   through the JDBC Forum (http://forums.mysql.com/list.php?39).
   You may also find help from other users in the other MySQL
   Forums, located at http://forums.mysql.com. See MySQL
   Community Support at the MySQL Forums
   (http://dev.mysql.com/doc/refman/5.7/en/forums.html).

17.2 How to Report Connector/J Bugs or Problems

   The normal place to report bugs is http://bugs.mysql.com/,
   which is the address for our bugs database. This database is
   public, and can be browsed and searched by anyone. If you log
   in to the system, you will also be able to enter new reports.

   If you find a sensitive security bug in MySQL Server, please
   let us know immediately by sending an email message to
   secalert_us@oracle.com. Exception: Support customers should
   report all problems, including security bugs, to Oracle
   Support at http://support.oracle.com/.

   Writing a good bug report takes patience, but doing it right
   the first time saves time both for us and for yourself. A
   good bug report, containing a full test case for the bug,
   makes it very likely that we will fix the bug in the next
   release.

   This section will help you write your report correctly so
   that you do not waste your time doing things that may not
   help us much or at all.

   If you have a repeatable bug report, please report it to the
   bugs database at http://bugs.mysql.com/. Any bug that we are
   able to repeat has a high chance of being fixed in the next
   MySQL release.

   To report other problems, you can use one of the MySQL
   mailing lists.

   Remember that it is possible for us to respond to a message
   containing too much information, but not to one containing
   too little. People often omit facts because they think they
   know the cause of a problem and assume that some details do
   not matter.

   A good principle is this: If you are in doubt about stating
   something, state it. It is faster and less troublesome to
   write a couple more lines in your report than to wait longer
   for the answer if we must ask you to provide information that
   was missing from the initial report.

   The most common errors made in bug reports are (a) not
   including the version number of Connector/J or MySQL used,
   and (b) not fully describing the platform on which
   Connector/J is installed (including the JVM version, and the
   platform type and version number that MySQL itself is
   installed on).

   This is highly relevant information, and in 99 cases out of
   100, the bug report is useless without it. Very often we get
   questions like, "Why doesn't this work for me?" Then we find
   that the feature requested wasn't implemented in that MySQL
   version, or that a bug described in a report has already been
   fixed in newer MySQL versions.

   Sometimes the error is platform-dependent; in such cases, it
   is next to impossible for us to fix anything without knowing
   the operating system and the version number of the platform.

   If at all possible, create a repeatable, standalone testcase
   that doesn't involve any third-party classes.

   To streamline this process, we ship a base class for
   testcases with Connector/J, named
   'com.mysql.jdbc.util.BaseBugReport'. To create a testcase for
   Connector/J using this class, create your own class that
   inherits from com.mysql.jdbc.util.BaseBugReport and override
   the methods setUp(), tearDown() and runTest().

   In the setUp() method, create code that creates your tables,
   and populates them with any data needed to demonstrate the
   bug.

   In the runTest() method, create code that demonstrates the
   bug using the tables and data you created in the setUp
   method.

   In the tearDown() method, drop any tables you created in the
   setUp() method.

   In any of the above three methods, use one of the variants of
   the getConnection() method to create a JDBC connection to
   MySQL:

     * getConnection() - Provides a connection to the JDBC URL
       specified in getUrl(). If a connection already exists,
       that connection is returned, otherwise a new connection
       is created.

     * getNewConnection() - Use this if you need to get a new
       connection for your bug report (that is, there is more
       than one connection involved).

     * getConnection(String url) - Returns a connection using
       the given URL.

     * getConnection(String url, Properties props) - Returns a
       connection using the given URL and properties.

   If you need to use a JDBC URL that is different from
   'jdbc:mysql:///test', override the method getUrl() as well.

   Use the assertTrue(boolean expression) and assertTrue(String
   failureMessage, boolean expression) methods to create
   conditions that must be met in your testcase demonstrating
   the behavior you are expecting (vs. the behavior you are
   observing, which is why you are most likely filing a bug
   report).

   Finally, create a main() method that creates a new instance
   of your testcase, and calls the run method:
public static void main(String[] args) throws Exception {
      new MyBugReport().run();
 }

   Once you have finished your testcase, and have verified that
   it demonstrates the bug you are reporting, upload it with
   your bug report to http://bugs.mysql.com/.
