persistenceUnit.java

@ApplicationScoped
public class PersistenceUnit {

  @javax.persistence.PersistenceUnit(unitName = "default")
  private EntityManagerFactory entityManagerFactory;

  @Produces
  @RequestScoped
  public EntityManager create() {
    return entityManagerFactory.createEntityManager();
  }

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