JDev Exception:Cannot acquire data source java:/app/jdbc/jdbc/DataSourceName.

Issue:

When you are invoking some operation that related to EJB entity persistence in weblogic using EclipseLink, you may come across the exception as following.

Caused by: Exception EclipseLink-7060 (Eclipse Persistence Services - 1.0.1 (Build 20080905)): org.eclipse.persistence
.exceptions.ValidationException
Exception Description: Cannot acquire data source java:/app/jdbc/jdbc/DataSourceName.
Internal Exception: javax.naming.NameNotFoundException: While trying to look up /app/jdbc/jdbc/DatabaseDevDS in /app/ejb/E
JB.jar#SessionEJB.; remaining name '/app/jdbc/jdbc/DataSourceName'
at org.eclipse.persistence.exceptions.ValidationException.cannotAcquireDataSource(ValidationException.java:429)
at org.eclipse.persistence.sessions.JNDIConnector.connect(JNDIConnector.java:123)
at org.eclipse.persistence.sessions.JNDIConnector.connect(JNDIConnector.java:94)
at org.eclipse.persistence.sessions.DatasourceLogin.connectToDatasource(DatasourceLogin.java:164)
at org.eclipse.persistence.internal.databaseaccess.DatasourceAccessor.connectInternal(DatasourceAccessor.java:32
4)

Solution:

Please check whether your JNDI name format is like java:/app/jdbc/jdbc/DataSourceName*)

There is a double "jdbc") as opposed to a global name (*DataSourceName*) in your JPA persistence.xml. It indicates that you are using an “application scoped” datasource and not a “globally scoped” datasource that is defined directly on your WebLogic server.

If you want to use an application scoped datasource on Oracle WebLogic server, please refer to

http://wiki.eclipse.org/EclipseLink/Examples/JPA/WLS_AppScoped_DataSource

and

http://wiki.eclipse.org/EclipseLink/Examples/JPA/WebLogic_Web_Tutorial#Application_Scoped_Datasource_Setup

The above enterprise application based tutorial using EclipseLink as the JPA provider describes a workaround for using an “application scoped” datasource when deployed on WebLogic 10.3 using both the normal <jta-data-source></jta-data-source>element and the overriding javax.persistence.jtaDataSource property, until the base WLS Server bug being tracked by EclipseLink bug# 246126 in http://bugs.eclipse.org/246126 is fixed shortly.

In addition, you’d better add following property to your persistence.xml:
1) Add a reference to the WebLogic platform
<property value="WebLogic_10" name="eclipselink.target-server"></property>

2) Verify that you have really defined your application scoped datasource with a double "jdbc" "java:/app/jdbc/jdbc/DatabaseDevDS"and didn't really mean "java:/app/jdbc/DatabaseDevDS" which is usually standard

see
http://wiki.eclipse.org/EclipseLink/Examples/JPA/WebLogic_Web_Tutorial#Persistence.xml
and an EclipseLink open source example that uses a globally define datasource in a WebLogic Web application tutorial using EclipseLink as the JPA provider
http://dev.eclipse.org/svnroot/rt/org.eclipse.persistence/trunk/examples/org.eclipse.persistence.example.jpa.server.weblogic.enterpriseEJB/ejbModule/META-INF/persistence.xml

Also, an additional workaround would be to globally define the datasource on your integrated WebLogic server and reference it as described in...
http://wiki.eclipse.org/EclipseLink/Examples/JPA/WebLogic_Web_Tutorial#Global_Scoped_Datasource_Setup

For the details, please refer to http://forums.oracle.com/forums/thread.jspa?threadID=828586