Packaging an Application with Both EJB 3.0 and EJB 2.1 EJBs

You can combine both EJB 3.0 and EJB 2.1 beans in your application. For example, you could have an application that contains three annotated EJB 3.0 entities without ejb-jar.xml, two EJB 2.1 entity beans with ejb-jar.xml, and three EJB 3.0 session beans with ebj-jar.xml, annotations, or both (in which case, the ejb-jar.xml overrides the annotations).