public class DataBaseProducer
{
    @PersistenceContext(unitName="default")
    private EntityManager entityManager;

    @Produces
    @TransactionScoped
    public EntityManager createEntityManager()
    {
        return this.entityManager;
    }

    public void dispose(@Disposes EntityManager entityManager)
    {
        if(entityManager.isOpen())
        {
            entityManager.close();
        }
    }
}