CODEWITHSUNDEEP
javagoogle-app-enginejpa-2.0datanucleus
Vitaly Olegovitch
Vitaly Olegovitch

Reputation: 3547

Appengine JPA update

Hi I am using Google App Engine SDK 1.7.3 and JPA for Datanucleus. I can't update an object that is in the variable t.

I have written my code as indicated in the accepted answer to this question.

If I use the code:

    PersistenceManager persistenceManager=JDOHelper.getPersistenceManager(t);
    persistenceManager.refresh(t);
    return t;

I get:

java.lang.UnsupportedOperationException: Method not supported with JPA
    at org.datanucleus.api.jpa.JPAPersistenceManager.refresh(JPAPersistenceManager.java:693)
    at com.appspot.diasporajava.dao.GenericDaoImpl.update(GenericDaoImpl.java:74)

If I use the code:

return this.emf.createEntityManager().merge(t);

Where emf is an EntityManagerFactory.

I get:

javax.persistence.PersistenceException: Object with id "com.appspot.diasporajava.entities.Post@447cc9c9" is managed by a different Object Manager
    at org.datanucleus.api.jpa.NucleusJPAHelper.getJPAExceptionForNucleusException(NucleusJPAHelper.java:302)
    at org.datanucleus.api.jpa.JPAEntityManager.merge(JPAEntityManager.java:576)
    at com.appspot.diasporajava.dao.GenericDaoImpl.update(GenericDaoImpl.java:76)

Do I have to keep open my persistence manager all the time?

A related ticket.

The ocde I use to create objects is the following:

@Override
@Transactional
public T create(final T t) {    
    EntityManager em = this.emf.createEntityManager();
    em.persist(t);
    em.close();
    return t;
}

Upvotes: 2

Views: 455

Answers (1)

Vitaly Olegovitch
Vitaly Olegovitch

Reputation: 3547

The problem is that I did not close the EntityManager when I got the object t the first time.

Upvotes: 2

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