Transaction through EJB3

[Jyoti Aggarwal]

Hi,

I created an application that has EJB3 and Hibernate3. Initially I was jus calling the method in Dao layer from EJB and there for every method get new hibernate session and do the transaction and so on...
Now i hav ben asked to do all the transaction from EJB layer itself. I have no clue how to begin with the same. i am using stateless session beans. and MySql database.

[Paul Sturrock]

I recommend you go through this useful tutorial.

[Jyoti Aggarwal]

Hi,

I am not able to undestarnd that is it necessary to use persistance.xml. Initially I was using hibernate.cfg.xml. If yes where am i going to map hbm.xml mapping and how to call the session
please its really urgent

[Paul Sturrock]

So you question is not about container managed transactions its about transaction scoped session management? In which case the Hibernate documentation will explain what to do.

[Jyoti Aggarwal]

I have already gone through that ....
Ok I have one DAO layer having sesssionFactory of hibernate. then there is this class doing all transaction

 public Session getSession() {
		// getting the session
		Session session = HibernateUtil.getSessionFactory().getCurrentSession();

		return session;
	}

	public Transaction getTransaction(Session session) {
		// getting the transaction
		Transaction transaction = session.beginTransaction();
		transaction.begin();
		return transaction;
	}

	public void commitNClose(Transaction transaction) {
		// Committing the transaction
		transaction.commit();
		HibernateUtil.getSessionFactory().close();
	}

	public void rollbackNClose(Transaction transaction) {
		// roll back the transaction
		transaction.rollback();
		HibernateUtil.getSessionFactory().close();
	}

   

In my EJB folder
I have put

 
@Stateless
@TransactionManagement(TransactionManagementType.CONTAINER)
@TransactionAttribute(TransactionAttributeType.REQUIRES_NEW)   

@PersistenceContext private EntityManager em;
@Resource private javax.transaction.UserTransaction userTx;
 

have no idead whether PersistenceContext private EntityManager em; is required or not

No how do i open transaction in ejb

[Paul Sturrock]

No how do i open transaction in ejb

See my first reply. The mechanism is called container managed transactions and is one of the basics of EJBs. I would strongly recommend you go through the linked tutorial before doing much more with EJBs. It will make your life much easier if you have a good grasp of the basics