Does the EJB programming model support inheritance?
Inheritance is supported in EJB in a limited fashion. Enterprise beans are made up of several parts including: a remote interface; a home interface, a bean class (implementation); and a deployment descriptor (see the FAQ What makes a Java class an enterprise bean? ).
The remote interface, which extends javax.ejb.EJBObject can be a subtype or a super-type of remote interfaces of other beans. This is also true of the home interface, which extends javax.ejb.EJBHome. The bean class, which implements either javax.ejb.EntityBean or javax.ejb.SessionBean can also be a subtype or super-type of the bean class used by another enterprise bean. Deployment descriptors are XML files, so there is no Object-Oriented (OO) inheritance in the deployment descriptor.