2.  Using a Third-Party DataSource

2.1. Managed and XA DataSources

You can use OpenJPA with any third-party javax.sql.DataSource . There are multiple ways of telling OpenJPA about a DataSource:

The features of OpenJPA's own DataSource can also be used with third-party implementations. OpenJPA layers on top of the third-party DataSource to provide the extra functionality. To configure these features use the openjpa.ConnectionFactoryProperties property described in the previous section.

Example 4.2.  Properties File for a Third-Party DataSource

<property name="openjpa.ConnectionDriverName" value="oracle.jdbc.pool.OracleDataSource"/>
<property name="openjpa.ConnectionProperties" 
    value="PortNumber=1521, ServerName=saturn, DatabaseName=solarsid, DriverType=thin"/>
<property name="openjpa.ConnectionFactoryProperties" value="QueryTimeout=5000"/>

2.1.  Managed and XA DataSources

Certain application servers automatically enlist their DataSource s in global transactions. When this is the case, OpenJPA should not attempt to commit the underlying connection, leaving JDBC transaction completion to the application server. To notify OpenJPA that your third-party DataSource is managed by the application server, use the jta-data-source element of your persistence.xml file or set the openjpa.ConnectionFactoryMode property to managed.

Note that OpenJPA can only use managed DataSources when it is also integrating with the application server's managed transactions. Also note that all XA DataSources are enlisted, and you must set this property when using any XA DataSource.

When using a managed DataSource, you should also configure a second unmanaged DataSource that OpenJPA can use to perform tasks that are independent of the global transaction. The most common of these tasks is updating the sequence table OpenJPA uses to generate unique primary key values for your datastore identity objects. Configure the second DataSource using the non-jta-data-source persistence.xml element, or OpenJPA's various "2" connection properties, such as openjpa.ConnectionFactory2Name or openjpa.Connection2DriverName. These properties are outlined in Chapter 2, Configuration .

Example 4.3.  Managed DataSource Configuration

<!-- managed DataSource -->
    <!-- use OpenJPA's built-in DataSource for unmanaged connections -->
    <property name="openjpa.Connection2UserName" value="scott"/>
    <property name="openjpa.Connection2Password" value="tiger"/>
    <property name="openjpa.Connection2URL" value="jdbc:oracle:thin:@CROM:1521:OpenJPADB"/>
    <property name="openjpa.Connection2DriverName" value="oracle.jdbc.driver.OracleDriver"/>