How to: Hibernate Criteria API and EJB 3.0

quietgamer · **Posted:** Fri Oct 27, 2006 6:09 pm

I try to figure out how to utilize the powerful api in EJB3.0 environment where Hibernate is hidden. Thanks for your comments.

christian · **Posted:** Sat Oct 28, 2006 3:13 am

((Session)entityManager.getDelegate()).createCriteria()

quietgamer · **Posted:** Thu Nov 02, 2006 1:51 pm

Obviously, if we do that, the ejb 3.0 application is no longer server independent, which means the server has to have the hibernate pm.

christian · **Posted:** Sat Nov 04, 2006 4:52 am

How else should it work? If a specification doesn't have a _feature_ you need, use a vendor extension. Why else would you have decided for a particular vendor and a particular implementation? Not only because it implements the specification, but also because it has extensions that are relevant for your application.

This mindset that vendor extensions are evil was what led to the nightmare and stagnation of EJB 1 and EJB 2. Stop it, embrace the product you decided to use. Absolute portability is not your primary problem, writing working and maintainable software is.

jbandi · **Joined:** Thu Jan 25, 2007 12:32 pm **Posts:** 6

The following did not work for me...

christian wrote:

((Session)entityManager.getDelegate()).createCriteria()

However this worked form me:

Code:

 HibernateEntityManager hem = ((HibernateEntityManager)em.getDelegate());
 Session session = hem.getSession();
 results = session.createCriteria(Book.class).list();
 

I hope this helps.

tsar bomba · **Joined:** Mon Nov 14, 2005 7:33 pm **Posts:** 73

I have to agree w/ Christian.

The Criteria API was not included in the EJB 3.0 spec, so if that's what you intend to use, you'll obviously have to go outside of the spec.

Honestly - and I don't think I'm alone here, portability should be the least of your concerns. If you're hopping app-servers, or heck, switching at all then you are part of a minority and the problem then doesn't lie in the spec but rather in the decisions your team made when designing the application.

Portability is vastly overrated and even if you stick to the spec, I'm sure you'll find several other "portability" problems anyhow. There are enough holes in the spec to allow varying behavior between fully compliant app servers.

For example - moving from Glassfish to JBoss was *anything* but a no-brainer for me, and I stayed 100% within the EJB 3.0 spec.

emmanuel · **Posted:** Mon Jan 29, 2007 4:10 am

jbandi wrote:

The following did not work for me...

christian wrote:

((Session)entityManager.getDelegate()).createCriteria()

However this worked form me:

Code:

 HibernateEntityManager hem = ((HibernateEntityManager)em.getDelegate());
 Session session = hem.getSession();
 results = session.createCriteria(Book.class).list();
 

I hope this helps.

A bug has been opened on JBoss EJB 3.0 check their JIRA isse to see if it is still open