Hibernate and EJB

flam70 · **Joined:** Thu Oct 02, 2003 8:02 am **Posts:** 45

I'd like to use hibernate with EJB.
I see that there's 2 categories of EJB : EJB Entity and EJB Session.
For each category, there's 2 sub-categories.
EJB Entity : BMP and CMP
EJB Session : stateless and statefull
I'd like to know the EJB's category that i can use with hibernate. As i understand, only EJB Entity deal with DataBase. So i deduct that we can't use hibernate with EJB Session.
Can someone helps me and explains to me the best way to do such an integration.

Thanks

christian · **Posted:** Wed Oct 15, 2003 4:58 am

You can use Hibernate as a persistence mechanism for Entity Beans with BMP. You can of course use Hibernate and plain JavaBeans with SessionBeans (the recommended approach). Please start reading some basic J2EE documentation and books.

flam70 · **Joined:** Thu Oct 02, 2003 8:02 am **Posts:** 45

Just another thing. Is it possible to substitute EJB by hibernate ?
I don't understand exactly if these 2 technologies are equivalent or complementary?

Thanks

christian · **Posted:** Wed Oct 15, 2003 5:00 am

Both.

emmanuel · **Posted:** Wed Oct 15, 2003 8:49 am

To be short
EJB session have no special link to DB.
It allows remote access, declarative transaction management, clustering, etc

EJB Entity map object world and Relational DB world, as Hibernate does. So yes EJB Entity and Hibernate do the same job

Entity pros:
- standard
- remote access (sorry must be a typo ;-))
- object pooling
- ...

Hibernate/JDO Pros:
- Entity are too Heavy
- no clear separation between object model and mapping mecanism
- can be used outside a J2EE container
- ...

So yes Hibernate and EJB are complementary

I personally use EJB Session and behind hibernate (no EJB Entity)