org.apache.avalon.excalibur.datasource

Class JdbcDataSource

java.lang.Object

org.apache.avalon.framework.logger.AbstractLogEnabled

org.apache.avalon.excalibur.datasource.JdbcDataSource

All Implemented Interfaces:

DataSourceComponent, org.apache.avalon.framework.activity.Disposable, org.apache.avalon.framework.component.Component, org.apache.avalon.framework.configuration.Configurable, org.apache.avalon.framework.logger.LogEnabled, org.apache.avalon.framework.thread.ThreadSafe

public class JdbcDataSource
extends org.apache.avalon.framework.logger.AbstractLogEnabled
implements DataSourceComponent, org.apache.avalon.framework.activity.Disposable

The Default implementation for DataSources in Avalon. This uses the normal java.sql.Connection object and java.sql.DriverManager.

Configuration Example:

   <jdbc>
     <pool-controller min="5" max="10" connection-class="my.overrided.ConnectionClass">
       <keep-alive disable="false" age="5000">select 1</keep-alive>
     </pool-controller>
     <auto-commit>true</auto-commit>
     <driver>com.database.jdbc.JdbcDriver</driver>
     <dburl>jdbc:driver://host/mydb</dburl>
     <user>username</user>
     <password>password</password>
   </jdbc>
 

Configuration Attributes:

• The min attribute is used to set the minimum size of the DataSource pool. When the Data Source is first initialized, the DataSource will automatically create this number of connections so they will be ready for use. (Defaults to "1")
• The max attribute is used to set the maximum number of connections which will be opened. If more concurrent connections are requested, a NoAvailableConnectionException will be thrown. (Defaults to "3")
• The connection-class attribute is used to override the Connection class returned by the DataSource from calls to getConnection(). Set this to "org.apache.avalon.excalibur.datasource.Jdbc3Connection" to gain access to JDBC3 features. Jdbc3Connection does not exist if your JVM does not support JDBC3. (Defaults to "org.apache.avalon.excalibur.datasource.JdbcConnection")
• The keep-alive element is used to override the query used to monitor the health of connections. If a connection has not been used for 5 seconds then before returning the connection from a call to getConnection(), the connection is first used to ping the database to make sure that it is still alive. Setting the disable attribute to true will disable this feature. Setting the age allows the 5 second age to be overridden. (Defaults to a query of "SELECT 1" and being enabled)
• The auto-commit element is used to override the default (true) value of the auto-commit policy. It ensures that the database connection that is returned to you is already in the proper mode. If you use transactions in your queries, you must set this to false.
• The driver element is used to specify the driver to use when connecting to the database. The specified class must be in the classpath. (Required)
• The dburl element is the JDBC connection string which will be used to connect to the database. (Required)
• The user and password attributes are used to specify the user and password for connections to the database. (Required)

Since:

4.0

Version:

CVS $Revision: 1.4 $ $Date: 2004/02/28 11:47:14 $

Author:

Avalon Development Team

Field Summary

Fields

Modifier and Type	Field and Description
protected JdbcConnectionPool	m_pool

Fields inherited from interface org.apache.avalon.excalibur.datasource.DataSourceComponent

ROLE

Constructor Summary

Constructors

Constructor and Description
JdbcDataSource()

Method Summary

Methods

Modifier and Type	Method and Description
void	configure(org.apache.avalon.framework.configuration.Configuration configuration) Configure and set up DB connection.
void	dispose() Dispose properly of the pool
java.sql.Connection	getConnection() Get the database connection

Methods inherited from class org.apache.avalon.framework.logger.AbstractLogEnabled

enableLogging, getLogger, setupLogger, setupLogger, setupLogger

Methods inherited from class java.lang.Object

clone, equals, finalize, getClass, hashCode, notify, notifyAll, toString, wait, wait, wait

Field Detail

m_pool

protected JdbcConnectionPool m_pool

Constructor Detail

JdbcDataSource

public JdbcDataSource()

Method Detail

configure

public void configure(org.apache.avalon.framework.configuration.Configuration configuration)
               throws org.apache.avalon.framework.configuration.ConfigurationException

Configure and set up DB connection. Here we set the connection information needed to create the Connection objects. It must be called only once.

Specified by:

configure in interface org.apache.avalon.framework.configuration.Configurable

Parameters:

conf - The Configuration object needed to describe the connection.

Throws:

org.apache.avalon.framework.configuration.ConfigurationException

getConnection

public java.sql.Connection getConnection()
                                  throws java.sql.SQLException

Get the database connection

Specified by:

getConnection in interface DataSourceComponent

Returns:

Connection a valid connection for you to use

Throws:

NoValidConnectionException - when there is no valid Connection wrapper available in the classloader.

NoAvailableConnectionException - when there are no more available Connections in the pool.

java.sql.SQLException

dispose

public void dispose()

Dispose properly of the pool

Specified by:

dispose in interface org.apache.avalon.framework.activity.Disposable