[OPENJPA-1803] Unwrap EntityManager to Connection

• Type: Improvement
• Status: Closed
• Priority: Major
• Resolution: Fixed
• Affects Version/s: 2.0.1
• Fix Version/s: 2.2.0
• Component/s: competitive, jpa
• Assignee: Richard G. Curtis
• Reporter: Harald Wellmann
• Created: 18/Sep/10 15:13
• Updated: 02/Feb/12 16:55
• Resolved: 21/Jun/11 15:48

Description

This is currently the recommended way to access the javax.sql.Connection underlying an EntityManager:

OpenJPAEntityManager oem = OpenJPAPersistence.cast(em);
Connection con = (Connection) oem.getConnection();

It would be more convenient to simply write

Connection con = em.unwrap(Connection.class);

That way, the client needing to access the Connection only depends on the javax.persistence API and not on org.apache.openjpa.*.

I believe the JPA 2.0 spec neither mandates nor forbids this functionality. It is supported by Eclipselink 2.x.