Multithreaded access to Derby database EclipseLink JPA using JTA

Question

I am trying to persist objects to a Derby database using EclipseLink JPA using the JTA transaction type in a Java Future.

When I am doing this, I am getting the following error:

javax.persistence.TransactionRequiredException:
Exception Description: No externally managed transaction is currently active for this thread

When I try to get a transaction via entityManager.getTransaction(), I get the message that this is not supported for JTA. Also I tried to use an EntityManagerFactory to create an entityManager, as I read that this version is thread safe. However, I then get the error that EntityManagerFactory can also not be used with JTA.

Persisting these objects on the main thread works perfectly. It is really a problem of the multi threading.

I am persisting the object like entityManager.persist(object);

Is there any way of persisting objects into Derby via EclipseLink JTA in another thread than the main thread? (Since this is a general question, I think it is not necessary to add sample code.)

Thanks a lot in advance!