EclipseLink/Examples/JPA/NativeMetadata

You may use the org.eclipse.persistence.jpa.JpaHelper class to obtain an EntityManager.

Using a server session

EntityManagerFactory emf = org.eclipse.persistence.jpa.JpaHelper.createEntityManagerFactory(serverSession);
EntityManager em = emf.createEntityManager();

Using a sessions.xml file

If you want to use EclipseLink or Oracle TopLink's native XML metadata within EclipseLink JPA this can be accomplished using API:

EntityManagerFactory emf = org.eclipse.persistence.jpa.JpaHelper.createEntityManagerFactory(sessionName);
EntityManager em = emf.createEntityManager();

or through the use of persistence unit properties:

TODO: Example of XML property config

TODO: Example of property config using properties map passed to Persistence.createEntityManagerFactory("pu-name", properties)