EJB.4.4 Standard Mapping to CORBA Protocols

To help interoperability for EJB environments that include systems from multiple vendors , we define a standard mapping of the Enterprise JavaBeans architecture client-view contract to the CORBA protocols.

The use of the EJB architecture to CORBA mapping by the EJB server is not a requirement for EJB 1.1 compliance. A later release of the J2EE platform is likely to require that the J2EE platform vendor implement the EJB architecture to CORBA mapping.

The EJB-to-CORBA mapping covers:

1. Mapping of the EJB architecture remote and home interfaces to RMI-IIOP. This mapping is an identity mapping because every remote and home interface is an RMI-IIOP interface.

2. Propagation of transaction context over IIOP.

3. Propagation of security context over IIOP.

4. Interoperable naming service.

The EJB-to-CORBA mapping not only enables on-the-wire interoperability among multiple vendors' implementations of the EJB container, but also enables clients written in languages other than the Java progamming language to access server-side applications written as enterprise beans through standard CORBA APIs.

The EJB-to-CORBA mapping depends on the standard CORBA object services protocols for the propagation of the transaction and security context.

The CORBA mapping is defined in a separate document.

While the EJB-to-CORBA mapping defines the mapping of the EJB application interfaces and transaction interoperability, the mapping must be used in conjunction with other CORBA standards to ensure full "on-the-wire" interoperability. For example, multiple EJB servers must agree on the security protocol to achieve seamless interoperability.

Figure EJB.4-2 illustrates a heterogeneous environment that includes systems from five different vendors.

Figure EJB.4-2. Heterogeneous EJB Environment