"mnrz" wrote : I don't like this sort of approaches but we had to :) | | I think it's very useful if they provide an annotation for injections with local JNDi names | Why ? ;> It is point of inheritance. Write noninvasive generalization which model one aspect of system, and every class can specyfy to its needs. Contract is only EntityManager, not JNDI. I avoid Jndi if I can, in OO objects should have contract betwen themselves not between object and global register like JNDI. You DAO even didnt have inherit GeneralDataAccessManipulator, may have: @PersistenceContext(name="systemXPU") private EntityManager entityManager; property dataManipulatorSystemX = new GeneralDataAccessManipulator(enityiyManager); Also I'm also pro named PU. Every @PersitenceContext should have name. View the original post : http://www.jboss.com/index.html?module=bb&op=viewtopic&p=4185975#... Reply to the post : http://www.jboss.com/index.html?module=bb&op=posting&mode=reply&a...