Question

I am using Hibernate (4.1.8.FINAL), MySQL (InnoDB) and I am experiencing a problem with saving multiple entities.

According to Hibernate documentation http://docs.jboss.org/hibernate/orm/4.1/manual/en-US/html/ch15.html the batch processing should be supported, but I am getting following exception:

org.hibernate.TransactionException: nested transactions not supported
    at org.hibernate.engine.transaction.spi.AbstractTransactionImpl.begin(AbstractTransactionImpl.java:152)
    at org.hibernate.internal.SessionImpl.beginTransaction(SessionImpl.java:1395)
    ...

Here’s the code I wrote (Class EntryDaoImpl.java):

@Transaction
public void saveAll(final Collection<T> entities) {
    if (CollectionUtils.isEmpty(entities)) {
        return;
    }
    final Session session = this.sessionFactory.getCurrentSession();
    Transaction tx = null;
    try {
        tx = session.beginTransaction();
        for (final T entity : entities) {
            session.saveOrUpdate(entity);
        }
        tx.commit();
    } catch (final RuntimeException e) {
        if (tx != null) {
            tx.rollback();
        }
        throw e;
    } finally {
        session.flush();
        session.clear();
    }
}

And here is the JUnit method:

@Test
public void deleteAddress() {
    Entry entry;
    // Entry 2 has three addresses (delete all those)
    entry = this.entryDao.findById(2);
    Assert.assertEquals(3, entry.getAddresses().size());
    entry.setAddresses(null);
    this.entryDao.saveAll(Collections.singleton(entry));
}

The exception also occurs if only one entity will be updated. I also tried with openSession() instead of getCurrentSession() but the exception would be following:

org.hibernate.HibernateException: Illegal attempt to associate a collection with two open sessions
    at org.hibernate.collection.internal.AbstractPersistentCollection.setCurrentSession(AbstractPersistentCollection.java:638)
    at org.hibernate.event.internal.OnUpdateVisitor.processCollection(OnUpdateVisitor.java:65) 

If I go without transaction logic then it works. During research with search engine I see many developers told that Hibernate doesn’t support transaction at all. Not sure if this statement is outdated. confused

So my question is: does Hibernate supports transaction (as described in documentation)? And/or can you tell me what is wrong with my code? Thank you 🙂

Answer 1

You are using both declarative transaction (@Transaction) as well as programatic transaction.

tx = session.beginTransaction();
for (final T entity : entities) {
    session.saveOrUpdate(entity);
}
tx.commit();

Since you are using both the transaction in the same code, Hibernate complains

org.hibernate.TransactionException: nested transactions not supported

Remove your Transaction annotation at the top of your class and it should work, else remove your beginTransaction and commit.

Hope it helps.