EntityManager - How to get it on a class that is not a SeamComponent

mpssantos.mpssantos.gmail.com Jan 21, 2009 11:34 AM

Hello!

I'm use to get my EntityManager as normal way on a Hibernate project

EntityManagerFactory emf = HibernateUtil.getEntityManagerFactory();

EntityManager em = emf.getEntityManager();

.....

em.close();

if im on a Seam component, specified by the @Name(name) annotation, we just have to do:

@PersistenceContext private EntityManager em;

But if i want to create a class that manage all the transactions with the database like creation, updates, removes, query's? How can i get the EntityManager? It is suppose to do on other way?

Thanks a lot!

1. Re: EntityManager - How to get it on a class that is not a SeamComponent

accless Jan 23, 2009 12:12 AM (in response to mpssantos.mpssantos.gmail.com)
So far, i can imagine of three ways:

1) EJB

@PersistenceContext private EntityManager entityManager;

No Seam needed for this injection, as the ejb-container will do it for you

2) SMPC

@In private EntityManager entityManager;

Seam is needed, as you are injecting the seam managed persistence context.

3) SMPC

EntityManager em = (EntityManager)Component.getInstance("entityManager");

Same as before. But in comparison you do not rely on a seam interceptor for the injection.
Very useful for components having the @ByPassInterceptor

Hope this helps you a bit...

Greetings
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