Hibernate/JPA - Entity listener not being called properly

Question

I'm trying to leverage EntityListener objects and callback methods within my Seam/Hibernate/JPA application. I'm using a Seam 2.2-managed persistence context on JBoss 5.1 with PostgreSQL 9.1 on the backend. I have the following entity declared:

@Entity(name = "TestEntity")
@EntityListeners(TestCallback.class)
@Table(name = "tbl_test")
public class TestEntity implements Serializable {

    private static final long serialVersionUID = 2016897066783042092L;

    @Id
    @GeneratedValue(strategy = GenerationType.SEQUENCE, generator = "xxx")
    @SequenceGenerator(name = "xxx", sequenceName = "xxx")
    @Index(name = "xxx")
    @DocumentId
    private Long id = null;

    @Column
    private String test = null;
...
}

along with the following EntityListener callback class:

public class TestCallback {

    /**
     * Logger for this class
     */
    private Log logger = null;

    public TestCallback() {
        logger = Logging.getLog(TestCallback.class);
    }

    @PrePersist
    public void prePersist(TestEntity e) {
        logger.debug("prePersist(TestEntity) - start"); //$NON-NLS-1$

        logger.debug("prePersist(TestEntity) - end"); //$NON-NLS-1$
    }

    @PostPersist
    public void postPersist(TestEntity e) {
        logger.debug("postPersist(TestEntity) - start"); //$NON-NLS-1$

        logger.debug("postPersist(TestEntity) - end"); //$NON-NLS-1$
    }

    @PostLoad
    public void postLoad(TestEntity e) {
        logger.debug("postLoad(TestEntity) - start"); //$NON-NLS-1$

        logger.debug("postLoad(TestEntity) - end"); //$NON-NLS-1$
    }

    @PreUpdate
    public void preUpdate(TestEntity e) {
        logger.debug("preUpdate(TestEntity) - start"); //$NON-NLS-1$

        logger.debug("preUpdate(TestEntity) - end"); //$NON-NLS-1$
    }

    @PostUpdate
    public void postUpdate(TestEntity e) {
        logger.debug("postUpdate(TestEntity) - start"); //$NON-NLS-1$

        logger.debug("postUpdate(TestEntity) - end"); //$NON-NLS-1$
    }

    @PreRemove
    public void preRemove(TestEntity e) {
        logger.debug("preRemove(TestEntity) - start"); //$NON-NLS-1$

        logger.debug("preRemove(TestEntity) - end"); //$NON-NLS-1$
    }

    @PostRemove
    public void postRemove(TestEntity e) {
        logger.debug("postRemove(TestEntity) - start"); //$NON-NLS-1$

        logger.debug("postRemove(TestEntity) - end"); //$NON-NLS-1$
    }
}

When I run my test, however, I do not see all of my callback methods being called as I would expect. I've run tests of the following scenarios:

• Persisting a new item
• Updating an existing item
• Loading an item
• Deleting an item

However, the only callbacks I see being called are:

• @PrePersist
• @PreRemove
• @PostLoad
• @PreUpdate

The remaining callbacks do not get executed as expected. Is this the normal behavior? Am I just misunderstanding it? Does this have something to do with the way Seam manages transactions? Or, am I just not doing something right?

I'd appreciate any help you can give.

EDIT: As requested, here is the exact code I'm calling and the output I receive:

Test 1:

public void runTest() {
    logger.debug("runTest() - start"); //$NON-NLS-1$

    TestEntity e = new TestEntity();
    e.setTest("XXX");

    this.entityManager.persist(e);
    this.entityManager.flush();
    this.entityManager.clear();

    logger.debug("runTest() - end"); //$NON-NLS-1$
}

Output 1:

12:27:56,307 INFO  [STDOUT] 29735 DEBUG myapp.test.web.actions.test.TestAction  -  - runTest() - start
12:27:56,312 INFO  [STDOUT] 29740 DEBUG myapp.test.entities.TestCallback  -  - prePersist(TestEntity) - start
12:27:56,312 INFO  [STDOUT] 29740 DEBUG myapp.test.entities.TestCallback  -  - prePersist(TestEntity) - end
12:27:56,347 INFO  [STDOUT] 29775 DEBUG myapp.test.web.actions.test.TestAction  -  - runTest() - end

Test 2:

public void runTest2() {
        logger.debug("runTest2() - start"); //$NON-NLS-1$

        String sql = "SELECT DISTINCT t FROM TestEntity t";
        Query q = this.entityManager.createQuery(sql);

        List<TestEntity> l = q.getResultList();
        for (int i = 0; i < l.size(); i++) {
            String x = l.get(i).getTest();
            logger.debug("runTest2() - String x=" + x); //$NON-NLS-1$
        }

        logger.debug("runTest2() - end"); //$NON-NLS-1$
    }

Output 2:

12:28:36,964 INFO  [STDOUT] 70392 DEBUG myapp.test.web.actions.test.TestAction  -  - runTest2() - start
12:28:36,982 INFO  [STDOUT] 70410 DEBUG myapp.test.entities.TestCallback  -  - postLoad(TestEntity) - start
12:28:36,982 INFO  [STDOUT] 70410 DEBUG myapp.test.entities.TestCallback  -  - postLoad(TestEntity) - end
12:28:36,982 INFO  [STDOUT] 70410 DEBUG myapp.test.web.actions.test.TestAction  -  - runTest2() - String x=XXX
12:28:36,983 INFO  [STDOUT] 70411 DEBUG myapp.test.web.actions.test.TestAction  -  - runTest2() - end

Test 3:

public void runTest3() {
        logger.debug("runTest3() - start"); //$NON-NLS-1$

        String sql = "SELECT DISTINCT t FROM TestEntity t";
        Query q = this.entityManager.createQuery(sql);

        List<TestEntity> l = q.getResultList();
        for (int i = 0; i < l.size(); i++) {
            l.get(i).setTest("YYY" + System.currentTimeMillis());
            this.entityManager.persist(l.get(i));
        }
        this.entityManager.flush();
        this.entityManager.clear();

        Random rand = new SecureRandom();

        q = this.entityManager.createQuery(sql);
        l = q.getResultList();
        for (int i = 0; i < l.size(); i++) {
            this.entityManager.remove(l.get(i));
        }

        this.entityManager.flush();
        this.entityManager.clear();

        logger.debug("runTest3() - end"); //$NON-NLS-1$
    }

Output 3:

12:30:00,404 INFO  [STDOUT] 153832 DEBUG myapp.test.web.actions.test.TestAction  -  - runTest3() - start
12:30:00,407 INFO  [STDOUT] 153835 DEBUG myapp.test.entities.TestCallback  -  - postLoad(TestEntity) - start
12:30:00,407 INFO  [STDOUT] 153835 DEBUG myapp.test.entities.TestCallback  -  - postLoad(TestEntity) - end
12:30:00,408 INFO  [STDOUT] 153836 DEBUG myapp.test.entities.TestCallback  -  - preUpdate(TestEntity) - start
12:30:00,408 INFO  [STDOUT] 153836 DEBUG myapp.test.entities.TestCallback  -  - preUpdate(TestEntity) - end
12:30:00,410 INFO  [STDOUT] 153838 DEBUG myapp.test.entities.TestCallback  -  - postLoad(TestEntity) - start
12:30:00,411 INFO  [STDOUT] 153839 DEBUG myapp.test.entities.TestCallback  -  - postLoad(TestEntity) - end
12:30:00,414 INFO  [STDOUT] 153842 DEBUG myapp.test.entities.TestCallback  -  - preRemove(TestEntity) - start
12:30:00,414 INFO  [STDOUT] 153842 DEBUG myapp.test.entities.TestCallback  -  - preRemove(TestEntity) - end
12:30:00,453 INFO  [STDOUT] 153881 DEBUG myapp.test.web.actions.test.TestAction  -  - runTest3() - end

Answer 1

Sorry if i give a wrong answer... i don't know Seam.

But in your subject you say "Hibernate/JPA" which is unclear. Do you persist entities using a Session from a SessionFactory, or an EntityManager from an EntityManagerFactory?

There is a big difference because if you use Seam with a SessionFactory, the big difference is that by default the JPA listeners (which fire your annotated callbacks) are not registred by default, while they are with an EntityManagerFactory. So it may be possible that you are using a SessionFactory, and that someone else on your project, who configured that session factory, only registered a subset of all the JPA callback listeners.

See: http://docs.jboss.org/hibernate/entitymanager/3.5/reference/en/html/configuration.html#d0e865

---

Edit: Ok sorry, you use an EntityManager...

but perhaps it would be a good idea to try to get that SessionFactory behind the EntityManagerFactory, and see which event listeners are registred. Are you alone on that application? If someone tried to register a custom/legacy eventlistener or something, he may have overriden a JPA eventlistener.

This can be achieved by something like that:

EntityManager em = ...
Session session = (Session)em.getDelegage()
SessionFactoryImpl sessionFactoryImpl = (SessionFactoryImpl)session.getSessionFactory();
EventListeners el = sessionFactoryImpl.getEventListeners()

And then you can look what's inside, for exemple, according to your problem, you can compare:

el.getPreLoadEventListeners()
el.getPreDeleteEventListeners()

And remember the "default behaviour" is: http://docs.jboss.org/hibernate/stable/entitymanager/reference/en/html_single/#d0e865

It seems that it is possible to easily override JPA default listeners, see that: http://docs.jboss.org/hibernate/entitymanager/3.6/reference/en/html/listeners.html

It would be nice if you show us your persistence.xml