I believe you're referring to Hibernate, which is an open source
Java Object Relational Mapping (ORM) persistence framework.
EJBs have two different types: session beans and entity beans. Session beans can and often are used in conjunction with classes which have been generated using the Hibernate framework.
EJB Entity beans are a different method of doing ORM. Entity beans do provide a high level of transactional safety for systems where there are a lot of concurrent transactions accessing the same data (such as airline reservations, for example). For applications that don't require this, Hibernate and other ORM frameworks will probably work better and be easier to implement.
Also note that EJB 3.0, which is due to be released soon is much better, easier, and has many of the same features as Hibernate.
This has nothing to do with
Struts, however, and would be better posted in either the EJB forum or the Object Relational Mapping forum.
[ December 22, 2005: Message edited by: Merrill Higginson ]