The Enterprise Server supports and is compliant with the Sun Microsystems Enterprise JavaBeans (EJB) architecture as defined by the Enterprise JavaBeans Specification, v3.0, also known as JSR 220.
The Enterprise Server is backward compatible with 1.1, 2.0, and 2.1 enterprise beans. However, to take advantage of version 3.0 features, you should develop new beans as 3.0 enterprise beans.
The main changes in the Enterprise JavaBeans Specification, v3.0 that impact enterprise beans in the Enterprise Server environment are as follows:
Definition of the Java language metadata annotations that can be used to annotate EJB applications. These metadata annotations are targeted at simplifying the developer's task, at reducing the number of program classes and interfaces the developer is required to implement, at encapsulation of environmental dependencies and JNDI access, and at eliminating the need for the developer to provide an EJB deployment descriptor.
Elimination of the requirement for home or EJB component interfaces for session beans. The required business interface for a session bean can be a plain Java interface rather than an EJBObject, EJBLocalObject, or java.rmi.Remote interface.
Elimination of all required interfaces for persistent entities. Specification of Java language metadata annotations and XML deployment descriptor elements for the object/relational mapping of persistent entities. For details about Java Persistence in the Enterprise Server, see Chapter 7, Using the Java Persistence API.
Container-managed persistence (CMP) is still supported for EJB 2.1 beans, for backward compatibility. For details, see Chapter 10, Using Container-Managed Persistence.