Unable to build EntityManagerFactory

[Adolfo Eloy]

I've assembled a JSF application with JPA in Eclipse deploying this as a WAR file into JBoss 5. I'm not using EJB.
I created a Managed Bean that calls a DaoFactory that works with JPA to do my database transactions.
When this DaoFactory is created, an EntityManager is created holding it as an instance variable of my DaoFactory, such demonstrated below:

	
        ...
        private EntityManager em;
	
	public JPADaoFactory() {
		if (em == null) {
			em = JPAUtil.getEMF("ProjetoLivros").createEntityManager();
		}
	}
        ...

When a Dao is created, the EntityManager instance is passed through a constructor as follows:

	
       ...
       @Override
	public ClienteDao getClienteDao() {
		return new JPAClienteDao([b]em[/b]);
	}
        ...

The problem is: The EntityManagerFactory can't be created such as JBoss output said:

Unable to build EntityManagerFactory
org.hibernate.HibernateException: The chosen transaction strategy
requires access to the JTA TransactionManager



My persistence.xml was:

    ...
	<persistence-unit name="ProjetoLivros" transaction-type="JTA">
		<jta-data-source>java:/jdbc/livros</jta-data-source>
    ...

So, to solve that problem I changed the transaction-type to RESOURCE-LOCAL, and instead of using jta-data-source I started using non-jta-datasource
which is demonstrated below:

    ...
	<persistence-unit name="ProjetoLivros" transaction-type="RESOURCE_LOCAL">
		<non-jta-data-source>java:/jdbc/livros</non-jta-data-source>
    ...

Now, the application works well creating the EntityManagerFactory and so I can persist my data.


I'd like to know why it happens with JBoss.
Does JTA cannot be used when I deploy like a WAR app? Does JTA only works with EJB?

Thanks in advance.

[ryan sukale]

Hi Adolfo,

I remember using Tomcat for running EJB's for experimental purposes and used a container managed entity manager. But since tomcat is not a EJB server, i had to use the JBoss embedded server for it. Using container managed transactions for an application that does not use EJB's seems quite out of place. If one could do that then one could just make any web app and leave the transaction management issues to the container, making life a lot easy(at least for small applications).

I think that the using container managed transactions and entitymanagers is closely bound to EJB's because the container knows about the life cycle of the EJB's and is in absolute control of their creation/access/destruction have complex processes to handle their memory issues. Quite unlike your own classes that would always be at the mercy of your mind. Its like you sacrifice the control over your classes to gain privileges like container managed transactions. But i dont know for sure what's the reason.

If there is a way to use container managed transactions elsewhere, i would certainly like to know how to do that as well.

Regards,
Ryan Sukale