
MySQL Connector/J Developer's 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 release 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/).

   Document generated on: 2013-01-25 (revision: 34037)
     _______________________________________________________

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

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Chapter 1. MySQL Connector/J

   This section explains how to configure and develop Java
   applications with MySQL Connector/J, the JDBC driver that is
   integrated with MySQL.

   For release 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/).

Chapter 2. Connector/J Versions

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

     * Connector/J 5.1 is the Type 4 pure Java JDBC driver, which
       conforms to the JDBC 3.0 and JDBC 4.0 specifications. It
       provides compatibility with all the functionality of MySQL,
       including 4.1, 5.0, 5.1, 5.4 and 5.5. Connector/J 5.1 provides
       ease of development features, including auto-registration with
       the Driver Manager, standardized validity checks, categorized
       SQLExceptions, support for the JDBC-4.0 XML processing, per
       connection client information, NCHAR
       (http://dev.mysql.com/doc/refman/5.5/en/char.html), NVARCHAR
       (http://dev.mysql.com/doc/refman/5.5/en/char.html) and NCLOB
       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, 5.0, 5.1, 5.4, 5.5 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 Java RTE 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 Java RTE required JDK required (to build
   source code)
   5.1 1.5.x, 1.6.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 the Development
   Source Tree"), you must use JDK 1.4.2 or newer to compile the
   Connector package. 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.

   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://www.ibiblio.org/maven/).

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

   Within Windows 2000, Windows XP, Windows Server 2003 and Windows
   Vista, 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"
   Chapter 8, "Load Balancing with Connector/J," and Chapter 9,
   "Failover with Connector/J." 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.

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

     * user

     * password

     * serverName (see the previous section about fail-over 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/5.5/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
       was 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/5.5/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/5.5/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/5.5/en/blob.html). BLOB
       (http://dev.mysql.com/doc/refman/5.5/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/5.5/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 the Development Source Tree

   Caution

   Read this section only if you are interested in helping us test
   our new code. To just get MySQL Connector/J up and running on your
   system, use a standard binary release distribution.

   To install MySQL Connector/J from the development source tree,
   make sure that you have the following prerequisites:

     * A Bazaar client, to check out the sources from our Launchpad
       repository (available from http://bazaar-vcs.org/).

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

     * JDK 1.4.2 or later. Although MySQL Connector/J can be be used
       with older JDKs, compiling it from source requires at least
       JDK 1.4.2. To build Connector/J 5.1 requires JDK 1.6.x and an
       older JDK such as JDK 1.5.x; point your JAVA_HOME environment
       variable at the older installation.

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

    1. Check out the latest code from the branch that you want with
       one of the following commands.
       The source code repository for MySQL Connector/J is located on
       Launchpad at https://code.launchpad.net/connectorj. To check
       out the latest development branch, use:
shell> bzr branch lp:connectorji
       This creates a connectorj subdirectory in the current
       directory that contains the latest sources for the requested
       branch.
       To check out the latest 5.1 code, use:
shell> bzr branch lp:connectorj/5.1
       This creates a 5.1 subdirectory in the current directory
       containing the latest 5.1 code.

    2. To build Connector/J 5.1, make sure that you have both JDK
       1.6.x installed and an older JDK such as JDK 1.5.x. This is
       because Connector/J supports both JDBC 3.0 (which was prior to
       JDK 1.6.x) and JDBC 4.0. Set your JAVA_HOME environment
       variable to the path of the older JDK installation.

    3. Change your current working directory to either the connectorj
       or 5.1 directory, depending on which branch you intend to
       build.

    4. To build Connector/J 5.1, edit the build.xml to reflect the
       location of your JDK 1.6.x installation. The lines to change
       are:
            <property name="com.mysql.jdbc.java6.javac" value="C:\jvm
s\jdk1.6.0\bin\javac.exe" />
            <property name="com.mysql.jdbc.java6.rtjar" value="C:\jvm
s\jdk1.6.0\jre\lib\rt.jar" />
       Alternatively, you can set the value of these property names
       through the Ant -D option.

    5. Issue the following command to compile the driver and create a
       .jar file suitable for installation:
shell> ant dist
       This creates a build directory in the current directory, where
       all build output will go. A directory is created in the build
       directory that includes the version number of the sources you
       are building from. This directory contains the sources,
       compiled .class files, and a .jar file suitable for
       deployment. For other possible targets, including ones that
       will create a fully packaged distribution, issue the following
       command:
shell> ant -projecthelp

    6. A newly created .jar file containing the JDBC driver will be
       placed in the directory build/mysql-connector-java-version.
       Install the newly created JDBC driver as you would a binary
       .jar file that you download from MySQL, by following the
       instructions in Section 3.2, "Installing the Driver and
       Configuring the CLASSPATH."

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

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 otherwise configuring software to
   use MySQL Connector/J.

JDBC URL Format

   The JDBC URL format for MySQL Connector/J is as follows, with
   items in square brackets ([, ]) being optional:
jdbc:mysql://[host][,failoverhost...][:port]/[database] ??
[?propertyName1][=propertyValue1][&propertyName2][=propertyValue2]...

   If the host name is not specified, it defaults to 127.0.0.1. If
   the port is not specified, it defaults to 3306, the default port
   number for MySQL servers.
jdbc:mysql://[host:port],[host:port].../[database] ??
[?propertyName1][=propertyValue1][&propertyName2][=propertyValue2]...

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

IPv6 Connections

   For IPv6 connections, use this alternative syntax to specify hosts
   in the URL, address=(key=value). Supported keys are:

     * (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)(user=t
est)/db

   Any other parameters are treated as host-specific properties that
   follow the conventions of the JDBC URL properties. This now allows
   per-host overrides of any configuration property for multi-host
   connections (that is, when using failover, load balancing, or
   replication). Limit the overrides to user, password, network
   timeouts and statement and metadata cache sizes; the results of
   other per-host overrides are not defined.

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.

Failover Support

   MySQL Connector/J has failover support. This enables the driver to
   fail over to any number of slave hosts and still perform read-only
   queries. Failover only happens when the connection is in an
   autoCommit(true) state, because failover cannot happen reliably
   when a transaction
   (http://dev.mysql.com/doc/refman/5.5/en/glossary.html#glos_transac
   tion) is in progress. Most application servers and connection
   pools set autoCommit to true at the end of every
   transaction/connection use.

   The failover functionality has the following behavior:

     * If the URL property autoReconnect is false: Failover only
       happens at connection initialization, and failback occurs when
       the driver determines that the first host has become available
       again.

     * If the URL property autoReconnect is true: Failover happens
       when the driver determines that the connection has failed
       (checked before every query), and falls back to the first host
       when it determines that the host has become available again
       (after queriesBeforeRetryMaster queries have been issued).

   In either case, whenever you are connected to a "failed-over"
   server, the connection is set to read-only state, so queries that
   attempt to modify data will throw exceptions (the query will never
   be processed by the MySQL server).

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.MysqlConnectionPoolDataSour
            ce

     * 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.
       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. 
   Property Name Definition Default Value Since Version 
   user The user to connect as   all versions
   password The password to use when connecting   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. com.mysql.jdbc.StandardSocketFactory
   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'. 0 3.0.1
   socketTimeout Timeout on network socket operations (0, the default
   means no timeout). 0 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.   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.   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.   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). com.mysql.jdbc.authentication.MysqlNativePasswordPlugin
   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" propery is not set).   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. true 5.1.23
   interactiveClient Set the CLIENT_INTERACTIVE flag, which tells
   MySQL to timeout connections based on INTERACTIVE_TIMEOUT instead
   of WAIT_TIMEOUT false 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.   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   3.1.4
   useCompression Use zlib compression when communicating with the
   server (true/false)? Defaults to 'false'. false 3.0.17

   Networking. 
   Property Name Definition Default Value Since Version 
   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'. -1
   5.1.8
   tcpKeepAlive If connecting using TCP/IP, should the driver set
   SO_KEEPALIVE? true 5.0.7
   tcpNoDelay If connecting using TCP/IP, should the driver set
   SO_TCP_NODELAY (disabling the Nagle Algorithm)? true 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) 0 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) 0 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. 0 5.0.7

   High Availability and Clustering. 
   Property Name Definition Default Value Since Version 
   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. false 1.1
   autoReconnectForPools Use a reconnection strategy appropriate for
   connection pools (defaults to 'false') false 3.1.3
   failOverReadOnly When failing over in autoReconnect mode, should
   the connection be set to 'read-only'? true 3.0.12
   maxReconnects Maximum number of reconnects to attempt if
   autoReconnect is true, default is '3'. 3 1.1
   reconnectAtTxEnd If autoReconnect is set to true, should the
   driver attempt reconnections at the end of every transaction?
   false 3.0.10
   retriesAllDown When using loadbalancing, 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. 120 5.1.6
   initialTimeout If autoReconnect is enabled, the initial time to
   wait between re-connect attempts (in seconds, defaults to '2'). 2
   1.1
   roundRobinLoadBalance When autoReconnect is enabled, and
   failoverReadonly is false, should we pick hosts to connect to on a
   round-robin basis? false 3.1.2
   queriesBeforeRetryMaster Number of queries to issue before falling
   back to master 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 master. Defaults to 50. 50 3.0.2
   secondsBeforeRetryMaster How long should the driver wait, when
   failed over, before attempting 30 3.0.2
   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
   connnection's count of commands sent to the server exceeds this
   value. 0 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
   connnection's lifetime exceeds this value. 0 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   5.0.1

   Security. 
   Property Name Definition Default Value Since Version 
   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. false 3.1.1
   useSSL Use SSL when communicating with the server (true/false),
   defaults to 'false' false 3.0.2
   requireSSL Require SSL connection if useSSL=true? (defaults to
   'false'). false 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. true 5.1.6
   clientCertificateKeyStoreUrl URL to the client certificate
   KeyStore (if not specified, use defaults)   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. JKS
   5.1.0
   clientCertificateKeyStorePassword Password for the client
   certificates KeyStore   5.1.0
   trustCertificateKeyStoreUrl URL to the trusted root certificate
   KeyStore (if not specified, use defaults)   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. JKS
   5.1.0
   trustCertificateKeyStorePassword Password for the trusted root
   certificates KeyStore   5.1.0
   allowLoadLocalInfile Should the driver allow use of 'LOAD DATA
   LOCAL INFILE...' (defaults to 'true'). true 3.0.3
   allowUrlInLocalInfile Should the driver allow URLs in 'LOAD DATA
   LOCAL INFILE' statements? false 3.1.4
   paranoid Take measures to prevent exposure sensitive information
   in error messages and clear data structures holding sensitive data
   when possible? (defaults to 'false') false 3.0.1
   passwordCharacterEncoding What character encoding is used for
   passwords? Leaving this set to the default value (null), uses the
   platform character set, which works for ISO8859_1 (i.e. "latin1")
   passwords. For passwords in other character encodings, the
   encoding will have to be specified with this property, as it's not
   possible for the driver to auto-detect this.   5.1.7

   Performance Extensions. 
   Property Name Definition Default Value Since Version 
   callableStmtCacheSize If 'cacheCallableStmts' is enabled, how many
   callable statements should be cached? 100 3.1.2
   metadataCacheSize The number of queries to cache ResultSetMetadata
   for if cacheResultSetMetaData is set to 'true' (default 50) 50
   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? false 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? false 5.1.7
   prepStmtCacheSize If prepared statement caching is enabled, how
   many prepared statements should be cached? 25 3.0.10
   prepStmtCacheSqlLimit If prepared statement caching is enabled,
   what's the largest SQL the driver will cache the parsing for? 256
   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. com.mysql.jdbc.PerConnectionLRUFactory 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 com.mysql.jdbc.PerVmServerConfigCacheFactory 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. true 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. true 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? false 5.0.0
   blobSendChunkSize Chunk to use when sending BLOB/CLOBs via
   ServerPreparedStatements 1048576 3.1.9
   cacheCallableStmts Should the driver cache the parsing stage of
   CallableStatements false 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? false 3.0.10
   cacheResultSetMetadata Should the driver cache ResultSetMetaData
   for Statements and PreparedStatements? (Req. JDK-1.4+, true/false,
   default 'false') false 3.1.1
   cacheServerConfiguration Should the driver cache the results of
   'SHOW VARIABLES' and 'SHOW COLLATION' on a per-URL basis? false
   3.1.5
   defaultFetchSize The driver will call setFetchSize(n) with this
   value on all newly-created Statements 0 3.1.9
   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. false 3.1.7
   dynamicCalendars Should the driver retrieve the default calendar
   when required, or cache it per connection/session? false 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)? false 3.1.3
   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. true 5.0.6
   holdResultsOpenOverStatementClose Should the driver close result
   sets on Statement.close() as required by the JDBC specification?
   false 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? 2048 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.
   random 5.0.6
   locatorFetchBufferSize If 'emulateLocators' is configured to
   'true', what size buffer should be used when fetching BLOB data
   for getBinaryInputStream? 1048576 3.2.1
   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. false
   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. true
   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? true 5.0.6
   useFastDateParsing Use internal String->Date/Time/Timestamp
   conversion routines to avoid excessive object creation? true 5.0.5
   useFastIntParsing Use internal String->Integer conversion routines
   to avoid excessive object creation? true 3.1.4
   useJvmCharsetConverters Always use the character encoding routines
   built into the JVM, rather than using lookup tables for
   single-byte character sets? false 5.0.1
   useReadAheadInput Use newer, optimized non-blocking, buffered
   input stream when reading from the server? true 3.1.5

   Debugging/Profiling. 
   Property Name Definition Default Value Since Version 
   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) com.mysql.jdbc.log.StandardLogger 3.1.1
   gatherPerfMetrics Should the driver gather performance metrics,
   and report them via the configured logger every
   'reportMetricsIntervalMillis' milliseconds? false 3.1.2
   profileSQL Trace queries and their execution/fetch times to the
   configured logger (true/false) defaults to 'false' false 3.1.0
   profileSql Deprecated, use 'profileSQL' instead. Trace queries and
   their execution/fetch times on STDERR (true/false) defaults to
   'false'   2.0.14
   reportMetricsIntervalMillis If 'gatherPerfMetrics' is enabled, how
   often should they be logged (in ms)? 30000 3.1.2
   maxQuerySizeToLog Controls the maximum length/size of a query that
   will get logged when profiling or tracing 2048 3.1.3
   packetDebugBufferSize The maximum number of packets to retain when
   'enablePacketDebug' is true 20 3.1.3
   slowQueryThresholdMillis If 'logSlowQueries' is enabled, how long
   should a query (in ms) before it is logged as 'slow'? 2000 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. 0 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')? false 3.1.1
   autoGenerateTestcaseScript Should the driver dump the SQL it is
   executing, including server-side prepared statements to STDERR?
   false 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? true 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
   com.mysql.jdbc.JDBC4CommentClientInfoProvider 5.1.0
   dumpMetadataOnColumnNotFound Should the driver dump the
   field-level metadata of a result set into the exception message
   when ResultSet.findColumn() fails? false 3.1.13
   dumpQueriesOnException Should the driver dump the contents of the
   query sent to the server in the message for SQLExceptions? false
   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 false
   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? false 3.1.2
   includeInnodbStatusInDeadlockExceptions Include the output of
   "SHOW ENGINE INNODB STATUS" in exception messages when deadlock
   exceptions are detected? false 5.0.7
   includeThreadDumpInDeadlockExceptions Include a current Java
   thread dump in exception messages when deadlock exceptions are
   detected? false 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". false 5.1.15
   logSlowQueries Should queries that take longer than
   'slowQueryThresholdMillis' be logged? false 3.1.2
   logXaCommands Should the driver log XA commands sent by
   MysqlXaConnection to the server, at the DEBUG level of logging?
   false 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.
   com.mysql.jdbc.profiler.LoggingProfilerEventHandler 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? 100 5.0.5
   traceProtocol Should trace-level network protocol be logged? false
   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)? false 5.0.7

   Miscellaneous. 
   Property Name Definition Default Value Since Version 
   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'
   true 1.1g
   characterEncoding If 'useUnicode' is set to true, what character
   encoding should the driver use when dealing with strings?
   (defaults is to 'autodetect')   1.1g
   characterSetResults Character set to tell the server to return
   results as.   3.0.13
   connectionCollation If set, tells the server to use this collation
   via 'set collation_connection'   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. false 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.   5.1.3
   utf8OutsideBmpIncludedColumnNamePattern Used to specify exclusion
   rules to "utf8OutsideBmpExcludedColumnNamePattern". The regex must
   follow the patterns used for the java.util.regex package.   5.1.3
   loadBalanceEnableJMX Enables JMX-based management of load-balanced
   connection groups, including live addition/removal of hosts from
   load-balancing pool. false 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.
   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. false
   5.1.7
   allowNanAndInf Should the driver allow NaN or +/- INF values in
   PreparedStatement.setDouble()? false 3.1.5
   autoClosePStmtStreams Should the driver automatically call
   .close() on streams/readers passed as arguments via set*()
   methods? false 3.1.12
   autoDeserialize Should the driver automatically detect and
   de-serialize objects stored in BLOB fields? false 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? false 5.0.8
   capitalizeTypeNames Capitalize type names in DatabaseMetaData?
   (usually only useful when using WebObjects, true/false, defaults
   to 'false') true 2.0.7
   clobCharacterEncoding The character encoding to use for sending
   and retrieving TEXT, MEDIUMTEXT and LONGTEXT values instead of the
   configured connection characterEncoding   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. false 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? false 5.1.7
   continueBatchOnError Should the driver continue processing batch
   commands if one statement fails. The JDBC spec allows either way
   (defaults to 'true'). true 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. false 3.1.9
   emptyStringsConvertToZero Should the driver allow conversions from
   empty string fields to numeric values of '0'? true 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. false
   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? true 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.   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?
   false 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? false 5.0.5
   ignoreNonTxTables Ignore non-transactional table warning for
   rollback? (defaults to 'false'). false 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. true
   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.   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. 0 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. 0 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.   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.
   com.mysql.jdbc.StandardLoadBalanceExceptionChecker 5.1.13
   loadBalancePingTimeout Time in milliseconds to wait for ping
   response from each of load-balanced physical connections when
   using load-balanced Connection. 0 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.   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.   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? false
   5.1.13
   maxRows The maximum number of rows to return (0, the default means
   return all rows). -1 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) 600 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? false 5.0.3
   noDatetimeStringSync Don't ensure that
   ResultSet.getDatetimeType().toString().equals(ResultSet.getString(
   )) false 3.1.7
   noTimezoneConversionForTimeType Don't convert TIME values using
   the server timezone if 'useTimezone'='true' false 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) true 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) true 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)? false 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)? false 5.0.6
   pedantic Follow the JDBC spec to the letter. false 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 false
   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. false 5.0.5
   processEscapeCodesForPrepStmts Should the driver process escape
   codes in queries that are prepared? true 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?
   false 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')?
   false 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. false
   3.1.11
   rollbackOnPooledClose Should the driver issue a rollback() when
   the logical connection in a pool is closed? true 3.0.15
   runningCTS13 Enables workarounds for bugs in Sun's JDBC compliance
   testsuite version 1.3 false 3.1.7
   serverTimezone Override detection/mapping of timezone. Used when
   timezone from server doesn't map to Java timezone   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.
   5.1.1
   strictFloatingPoint Used only in older versions of compliance test
   false 3.0.0
   strictUpdates Should the driver do strict checking (all primary
   keys selected) of updatable result sets (true, false, defaults to
   'true')? true 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)? true 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? false
   3.1.9
   treatUtilDateAsTimestamp Should the driver treat java.util.Date as
   a TIMESTAMP for the purposes of PreparedStatement.setObject()?
   true 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') false
   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. false 5.1.7
   useGmtMillisForDatetimes Convert between session timezone and GMT
   before creating Date and Timestamp instances (value of "false" is
   legacy behavior, "true" leads to more JDBC-compliant behavior.
   false 3.1.12
   useHostsInPrivileges Add '@hostname' to users in
   DatabaseMetaData.getColumn/TablePrivileges() (true/false),
   defaults to 'true'. true 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? false 5.0.0
   useJDBCCompliantTimezoneShift Should the driver use JDBC-compliant
   rules when converting TIME/TIMESTAMP/DATETIME values' timezone
   information for those JDBC arguments which take a
   java.util.Calendar argument? (Notice that this option is exclusive
   of the "useTimezone=true" configuration option.) false 5.0.0
   useLegacyDatetimeCode Use code for DATE/TIME/DATETIME/TIMESTAMP
   handling in result sets and statements that consistently handles
   timezone 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? true 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. false
   5.0.4
   useOldUTF8Behavior Use the UTF-8 behavior the driver did when
   communicating with 4.0 and older servers false 3.1.6
   useOnlyServerErrorMessages Don't prepend 'standard' SQLState error
   messages to error messages returned by the server. true 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. false 5.0.5
   useServerPrepStmts Use server-side prepared statements if the
   server supports them? false 3.1.0
   useSqlStateCodes Use SQL Standard state codes instead of 'legacy'
   X/Open/SQL state codes (true/false), default is 'true' true 3.1.3
   useStreamLengthsInPrepStmts Honor stream length parameter in
   PreparedStatement/ResultSet.setXXXStream() method calls
   (true/false, defaults to 'true')? true 3.0.2
   useTimezone Convert time/date types between client and server
   timezones (true/false, defaults to 'false')? false 3.0.2
   useUnbufferedInput Don't use BufferedInputStream for reading data
   from the server true 3.0.11
   yearIsDateType Should the JDBC driver treat the MySQL type "YEAR"
   as a java.sql.Date, or as a SHORT? true 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". exception 3.1.4

   Connector/J also supports access to MySQL using named pipes on
   Windows NT, Windows 2000, or Windows XP using the
   NamedPipeSocketFactory as a plugin-socket factory using the
   socketFactory property. 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, use:
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 a 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
gatherPerMetrics=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 passes all of the tests in the publicly
   available version of Sun's JDBC compliance test suite. This
   section gives details on a interface-by-interface level about
   implementation decisions that might affect how you code
   applications with MySQL Connector/J. The JDBC specification is
   vague about how certain functionality should be implemented, or
   the specification enables leeway in implementation.

     * 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/5.5/en/select.html) must
            reference only one table. The table must have a primary
            key
            (http://dev.mysql.com/doc/refman/5.5/en/glossary.html#glo
            s_primary_key).

          + The SELECT
            (http://dev.mysql.com/doc/refman/5.5/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/5.5/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/5.5/en/glossary.html#glos_for
       eign_key) information (getImportedKeys()/getExportedKeys() and
       getCrossReference()) is only available from InnoDB
       (http://dev.mysql.com/doc/refman/5.5/en/innodb-storage-engine.
       html) tables. The driver uses SHOW CREATE TABLE
       (http://dev.mysql.com/doc/refman/5.5/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/5.5/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/5.5/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/5.5/en/load-data.html)
            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/5.5/en/load-data.html)
            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/5.5/en/load-data.html).
            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/5.5/en/load-data.html)
            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 java.sql.Types classes see Java 2 Platform
   Types
   (http://java.sun.com/j2se/1.4.2/docs/api/java/sql/Types.html).

   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/5.5/en/server-system-variables.ht
   ml#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/5.5/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/5.5/en/server-system-variables.ht
   ml#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. The performance
   penalty for enabling SSL is an increase in query processing time
   between 35% and 50%, depending on the size of the query, and the
   amount of data it returns.

   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://developer.java.sun.com/developer/bugParade/bugs/4273544
       .html

     * 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 Configuring MySQL for SSL
       (http://dev.mysql.com/doc/refman/5.5/en/configuring-for-ssl.ht
       ml).

     * 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 -key
store 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=MySQL AB, L=Orenburg, ST=Some-State, C=RU
Issuer: EMAILADDRESS=walrus@example.com, CN=Walrus,
       O=MySQL AB, 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 my
sqlClientCertificate

   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]:  MySQL AB
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=MySQL AB,
 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_fil
e");
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 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/5.5/en/pam-authentication-plu
       gin.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/5.5/en/cleartext-authenticati
       on-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

   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), this replication-aware
   connection will use one of the slave connections, which are
   load-balanced per-vm using a round-robin scheme (a given
   connection is sticky to a slave unless that slave is removed from
   service). 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 o
ne
    // from the list
    //
    conn.setReadOnly(true);
    ResultSet rs =
      conn.createStatement().executeQuery("SELECT a,b FROM alt_table"
);
     .......
  }
}

   Consider investigating 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 Pool (lbpool)
   (http://code.tailrank.com/lbpool).

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 S1000 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 S1000 42000
   1045 ER_ACCESS_DENIED_ERROR 28000 28000
   1047 ER_UNKNOWN_COM_ERROR 08S01 HY000
   1050 ER_TABLE_EXISTS_ERROR S1000 42S01
   1051 ER_BAD_TABLE_ERROR 42S02 42S02
   1052 ER_NON_UNIQ_ERROR S1000 23000
   1053 ER_SERVER_SHUTDOWN S1000 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 S1000 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 S1000 42000
   1091 ER_CANT_DROP_FIELD_OR_KEY S1000 42000
   1101 ER_BLOB_CANT_HAVE_DEFAULT S1000 42000
   1102 ER_WRONG_DB_NAME S1000 42000
   1103 ER_WRONG_TABLE_NAME S1000 42000
   1104 ER_TOO_BIG_SELECT S1000 42000
   1106 ER_UNKNOWN_PROCEDURE S1000 42000
   1107 ER_WRONG_PARAMCOUNT_TO_PROCEDURE S1000 42000
   1109 ER_UNKNOWN_TABLE S1000 42S02
   1110 ER_FIELD_SPECIFIED_TWICE S1000 42000
   1112 ER_UNSUPPORTED_EXTENSION S1000 42000
   1113 ER_TABLE_MUST_HAVE_COLUMNS S1000 42000
   1115 ER_UNKNOWN_CHARACTER_SET S1000 42000
   1118 ER_TOO_BIG_ROWSIZE S1000 42000
   1120 ER_WRONG_OUTER_JOIN S1000 42000
   1121 ER_NULL_COLUMN_IN_INDEX S1000 42000
   1129 ER_HOST_IS_BLOCKED 08004 HY000
   1130 ER_HOST_NOT_PRIVILEGED 08004 HY000
   1131 ER_PASSWORD_ANONYMOUS_USER S1000 42000
   1132 ER_PASSWORD_NOT_ALLOWED S1000 42000
   1133 ER_PASSWORD_NO_MATCH S1000 42000
   1136 ER_WRONG_VALUE_COUNT_ON_ROW S1000 21S01
   1138 ER_INVALID_USE_OF_NULL S1000 42000
   1139 ER_REGEXP_ERROR S1000 42000
   1140 ER_MIX_OF_GROUP_FUNC_AND_FIELDS S1000 42000
   1141 ER_NONEXISTING_GRANT S1000 42000
   1142 ER_TABLEACCESS_DENIED_ERROR S1000 42000
   1143 ER_COLUMNACCESS_DENIED_ERROR S1000 42000
   1144 ER_ILLEGAL_GRANT_FOR_TABLE S1000 42000
   1145 ER_GRANT_WRONG_HOST_OR_USER S1000 42000
   1146 ER_NO_SUCH_TABLE S1000 42S02
   1147 ER_NONEXISTING_TABLE_GRANT S1000 42000
   1148 ER_NOT_ALLOWED_COMMAND S1000 42000
   1149 ER_SYNTAX_ERROR S1000 42000
   1152 ER_ABORTING_CONNECTION S1000 08S01
   1153 ER_NET_PACKET_TOO_LARGE S1000 08S01
   1154 ER_NET_READ_ERROR_FROM_PIPE S1000 08S01
   1155 ER_NET_FCNTL_ERROR S1000 08S01
   1156 ER_NET_PACKETS_OUT_OF_ORDER S1000 08S01
   1157 ER_NET_UNCOMPRESS_ERROR S1000 08S01
   1158 ER_NET_READ_ERROR S1000 08S01
   1159 ER_NET_READ_INTERRUPTED S1000 08S01
   1160 ER_NET_ERROR_ON_WRITE S1000 08S01
   1161 ER_NET_WRITE_INTERRUPTED S1000 08S01
   1162 ER_TOO_LONG_STRING S1000 42000
   1163 ER_TABLE_CANT_HANDLE_BLOB S1000 42000
   1164 ER_TABLE_CANT_HANDLE_AUTO_INCREMENT S1000 42000
   1166 ER_WRONG_COLUMN_NAME S1000 42000
   1167 ER_WRONG_KEY_COLUMN S1000 42000
   1169 ER_DUP_UNIQUE S1000 23000
   1170 ER_BLOB_KEY_WITHOUT_LENGTH S1000 42000
   1171 ER_PRIMARY_CANT_HAVE_NULL S1000 42000
   1172 ER_TOO_MANY_ROWS S1000 42000
   1173 ER_REQUIRES_PRIMARY_KEY S1000 42000
   1177 ER_CHECK_NO_SUCH_TABLE S1000 42000
   1178 ER_CHECK_NOT_IMPLEMENTED S1000 42000
   1179 ER_CANT_DO_THIS_DURING_AN_TRANSACTION S1000 25000
   1184 ER_NEW_ABORTING_CONNECTION S1000 08S01
   1189 ER_MASTER_NET_READ S1000 08S01
   1190 ER_MASTER_NET_WRITE S1000 08S01
   1203 ER_TOO_MANY_USER_CONNECTIONS S1000 42000
   1205 ER_LOCK_WAIT_TIMEOUT 41000 41000
   1207 ER_READ_ONLY_TRANSACTION S1000 25000
   1211 ER_NO_PERMISSION_TO_CREATE_USER S1000 42000
   1213 ER_LOCK_DEADLOCK 41000 40001
   1216 ER_NO_REFERENCED_ROW S1000 23000
   1217 ER_ROW_IS_REFERENCED S1000 23000
   1218 ER_CONNECT_TO_MASTER S1000 08S01
   1222 ER_WRONG_NUMBER_OF_COLUMNS_IN_SELECT S1000 21000
   1226 ER_USER_LIMIT_REACHED S1000 42000
   1230 ER_NO_DEFAULT S1000 42000
   1231 ER_WRONG_VALUE_FOR_VAR S1000 42000
   1232 ER_WRONG_TYPE_FOR_VAR S1000 42000
   1234 ER_CANT_USE_OPTION_HERE S1000 42000
   1235 ER_NOT_SUPPORTED_YET S1000 42000
   1239 ER_WRONG_FK_DEF S1000 42000
   1241 ER_OPERAND_COLUMNS S1000 21000
   1242 ER_SUBQUERY_NO_1_ROW S1000 21000
   1247 ER_ILLEGAL_REFERENCE S1000 42S22
   1248 ER_DERIVED_MUST_HAVE_ALIAS S1000 42000
   1249 ER_SELECT_REDUCED S1000 01000
   1250 ER_TABLENAME_NOT_ALLOWED_HERE S1000 42000
   1251 ER_NOT_SUPPORTED_AUTH_MODE S1000 08004
   1252 ER_SPATIAL_CANT_HAVE_NULL S1000 42000
   1253 ER_COLLATION_CHARSET_MISMATCH S1000 42000
   1261 ER_WARN_TOO_FEW_RECORDS S1000 01000
   1262 ER_WARN_TOO_MANY_RECORDS S1000 01000
   1263 ER_WARN_NULL_TO_NOTNULL S1000 01000
   1264 ER_WARN_DATA_OUT_OF_RANGE S1000 01000
   1265 ER_WARN_DATA_TRUNCATED S1000 01000
   1280 ER_WRONG_NAME_FOR_INDEX S1000 42000
   1281 ER_WRONG_NAME_FOR_CATALOG S1000 42000
   1286 ER_UNKNOWN_STORAGE_ENGINE S1000 42000

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 section Section
   6.1, "Connecting to MySQL Using the JDBC DriverManager Interface"
   before working with these examples.

   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=monty&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/5.5/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/5.5/en/select.html) or
   an UPDATE
   (http://dev.mysql.com/doc/refman/5.5/en/update.html)/INSERT
   (http://dev.mysql.com/doc/refman/5.5/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/5.5/en/select.html), or false if
   it was an UPDATE
   (http://dev.mysql.com/doc/refman/5.5/en/update.html), INSERT
   (http://dev.mysql.com/doc/refman/5.5/en/insert.html), or DELETE
   (http://dev.mysql.com/doc/refman/5.5/en/delete.html) statement. If
   the statement was a SELECT
   (http://dev.mysql.com/doc/refman/5.5/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/5.5/en/update.html), INSERT
   (http://dev.mysql.com/doc/refman/5.5/en/insert.html), or DELETE
   (http://dev.mysql.com/doc/refman/5.5/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 previo
us 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
   http://dev.mysql.com/doc/mysql/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/5.5/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/5.5/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(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))");
    //
    // 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
    }
    rs.close();
    rs = null;
    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
    }
    rs.close();
    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");
    rs.close();
    rs = null;
    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: 2

   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/5.5/en/glossary.html#glos_thread)
   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/5.5/en/glossary.html#glos_transac
   tion), 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 lead to unpredictable
       behavior under load.

Using Connection Pooling with Connector/J

   Sun has standardized the concept of connection pooling in JDBC
   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 instance
s

          * 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;
            }
        }
    }
}

   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 Sun'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. 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.

   There are two connection string options 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
   string options, 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, ClassNo
tFoundException {
        Class.forName("com.mysql.jdbc.Driver");
        return DriverManager.getConnection(URL, "root", "");
    }
    static void executeSimpleTransaction(Connection c, int conn, int
trans){
        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 Chapter 9, "Failover with Connector/J."

Chapter 9. Failover with Connector/J

   Connector/J provides a useful load-balancing implementation for
   Cluster or multi-master deployments, as explained in Chapter 8,
   "Load Balancing with Connector/J." 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.SQLTransientConnecti
onException

   While the three fail-over 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 10. 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 11. 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-examples-h
   owto.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 ' S
QL
state: null

   Note that the auto-loading of drivers having the
   META-INF/service/java.sql.Driver class in JDBC 4.0 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 12. 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</connectio
n-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 13. 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.DriverManagerDataSo
urce">
    <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.PropertyPlaceholderC
onfigurer">
    <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.C
ode " +
        "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.

13.1. 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 paramete
rs
         NamedParameterJdbcTemplate template =
         new NamedParameterJdbcTemplate(dataSource);
         // A java.util.Map is used to provide values for the paramet
ers
         Map params = new HashMap();
         params.put("country", cntryCode);
         // We query for an Object and specify what class we are expe
cting
         return (String)template.queryForObject(queryString, params,
String.class);
     }
    /**

    * A JavaBean setter-style method to allow Spring to inject the da
ta 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.

13.2. 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.DataSourceTransactionMan
ager">
    <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.

13.3. 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 14. 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#top).

   Once Glassfish is installed you will need to make sure it can
   access MySQL Connector/J. To do this copy the MySQL Connector/J
   JAR file to the directory GLASSFISH_INSTALL/glassfish/lib. For
   example, copy mysql-connector-java-5.1.12-bin.jar to
   C:\glassfishv3\glassfish\lib. Restart the Glassfish Application
   Server.

   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.
   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.

14.1. 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:
xsi="http://www.w3.org/2001/XMLSchema-instance" xsi:schemaLocation="h
ttp://java.sun.com/xml/ns/j2ee http://java.sun.com/xml/ns/j2ee/web-ap
p_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 Applicat
ion Server 8.1 Servlet 2.4//EN" "http://www.sun.com/software/appserve
r/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.

14.2. 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/MySQLDataSourc
e");
      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
   14.1, "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 nto 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 14.1, "A Simple JSP Application
   with Glassfish, Connector/J and MySQL," no additional changes are
   required.

   Whe 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 Hello
WebServlet.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 14.1, "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 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

     * 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 fail
ed
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.j
ava: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/5.5/en/glossary.html#glos_pri
       mary_key) that is either FLOAT
       (http://dev.mysql.com/doc/refman/5.5/en/floating-point-types.h
       tml) or compound primary key that uses FLOAT
       (http://dev.mysql.com/doc/refman/5.5/en/floating-point-types.h
       tml) 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/5.5/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/5.5/en/server-system-variable
       s.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

   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/5.5/en/grant.html) statement to
   your MySQL Server. See GRANT Syntax
   (http://dev.mysql.com/doc/refman/5.5/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 go
ing
            // 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/5.5/en/glossary.html#glos_primary
   _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/5.5/en/update.html) or
   DELETE (http://dev.mysql.com/doc/refman/5.5/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/5.5/en/server-options.html#option
   _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/5.5/en/can-not-connect-to-server.
   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 fail
ed
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.j
ava: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/5.5/en/glossary.html#glos_primary
   _key) that is either FLOAT
   (http://dev.mysql.com/doc/refman/5.5/en/floating-point-types.html)
   or compound primary key that uses FLOAT
   (http://dev.mysql.com/doc/refman/5.5/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/5.5/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/5.5/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/5.5/en/floating-point-types.html)
   or DECIMAL
   (http://dev.mysql.com/doc/refman/5.5/en/fixed-point-types.html)
   types in place of FLOAT
   (http://dev.mysql.com/doc/refman/5.5/en/floating-point-types.html)
   .

   15.11: You get an ER_NET_PACKET_TOO_LARGE
   (http://dev.mysql.com/doc/refman/5.5/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/5.5/en/server-system-variables.ht
   ml#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 cust
omer='Smith'");
conn.createStatement().execute(
  "UPDATE savings_account SET balance = balance + 1000.00 WHERE custo
mer='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. Connector/J Support

16.1. 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/5.5/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/5.5/en/forums.html).

16.2. 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/.

Appendix A. Licenses for Third-Party Components

MySQL Connector/J


     * Section A.1, "Ant-Contrib License"

     * Section A.2, "c3p0 JDBC Library License"

     * Section A.3, "GNU Lesser General Public License Version 2.1,
       February 1999"

     * Section A.4, "jboss-common-jdbc-wrapper.jar License"

     * Section A.5, "Simple Logging Facade for Java (SLF4J) License"

A.1. Ant-Contrib License

   The following software may be included in this product:
   Ant-Contrib
Ant-Contrib
Copyright (c) 2001-2003 Ant-Contrib project. All rights reserved.
Licensed under the Apache 1.1 License Agreement, a copy of which is r
eproduced below.

The Apache Software License, Version 1.1

Copyright (c) 2001-2003 Ant-Contrib project.  All rights reserved.

 Redistribution and use in source and binary forms, with or without
 modification, are permitted provided that the following conditions
 are met:


 1. Redistributions of source code must retain the above copyright
    notice, this list of conditions and the following disclaimer.


 2. Redistributions in binary form must reproduce the above copyright
    notice, this list of conditions and the following disclaimer in
    the documentation and/or other materials provided with the
    distribution.


 3. The end-user documentation included with the redistribution, if
    any, must include the following acknowlegement:
       "This product includes software developed by the
        Ant-Contrib project (http://sourceforge.net/projects/ant-cont
rib)."
    Alternately, this acknowlegement may appear in the software itsel
f,
    if and wherever such third-party acknowlegements normally appear.


 4. The name Ant-Contrib must not be used to endorse or promote
    products derived from this software without prior written
    permission. For written permission, please contact
    ant-contrib-developers@lists.sourceforge.net.


 5. Products derived from this software may not be called "Ant-Contri
b"
    nor may "Ant-Contrib" appear in their names without prior written
    permission of the Ant-Contrib project.

 THIS SOFTWARE IS PROVIDED ``AS IS'' AND ANY EXPRESSED OR IMPLIED
 WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES
 OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE
 DISCLAIMED.  IN NO EVENT SHALL THE ANT-CONTRIB PROJECT OR ITS
 CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
 SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
 LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF
 USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND
 ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY,
 OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT
 OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
 SUCH DAMAGE.

A.2. c3p0 JDBC Library License

   You are receiving a copy of c3p0-0.9.1-pre6.jar in both source and
   object code in the following /src/lib/c3p0-0.9.1-pre6.jar. The
   terms of the Oracle license do NOT apply to c3p0-0.9.1-pre6.jar;
   it is licensed under the following license, separately from the
   Oracle programs you receive. If you do not wish to install this
   library, you may remove the file /src/lib/c3p0-0.9.1-pre6.jar, but
   the Oracle program might not operate properly or at all without
   the library.

   This component is licensed under Section A.3, "GNU Lesser General
   Public License Version 2.1, February 1999."

A.3. GNU Lesser General Public License Version 2.1, February 1999

The following applies to all products licensed under the
GNU Lesser General Public License, Version 2.1: You may
not use the identified files except in compliance with
the GNU Lesser General Public License, Version 2.1 (the
"License"). You may obtain a copy of the License at
http://www.gnu.org/licenses/lgpl-2.1.html. A copy of the
license is also reproduced below. Unless required by
applicable law or agreed to in writing, software distributed
under the License is distributed on an "AS IS" BASIS,
WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express
or implied. See the License for the specific language governing
permissions and limitations under the License.

                  GNU LESSER GENERAL PUBLIC LICENSE
                       Version 2.1, February 1999

 Copyright (C) 1991, 1999 Free Software Foundation, Inc.
 51 Franklin Street, Fifth Floor, Boston, MA  02110-1301  USA
 Everyone is permitted to copy and distribute verbatim copies
 of this license document, but changing it is not allowed.

[This is the first released version of the Lesser GPL.  It also count
s
 as the successor of the GNU Library Public License, version 2, hence
 the version number 2.1.]

                            Preamble

  The licenses for most software are designed to take away your
freedom to share and change it.  By contrast, the GNU General Public
Licenses are intended to guarantee your freedom to share and change
free software--to make sure the software is free for all its users.

  This license, the Lesser General Public License, applies to some
specially designated software packages--typically libraries--of the
Free Software Foundation and other authors who decide to use it.  You
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