RMI-IIOP 

RMI-IIOP is another development framework that is used for developing applications based on the Distributed Object Model. This framework enhances the standard RMI to work with the Internet Inter-ORB Protocol (IIOP). Since IIOP is the communication protocol of CORBA, you can use the RMI-IIOP to connect your Java remote objects to CORBA clients. It also works well for Java-to-Java objects communication over IIOP.

CORBA technology provides a language-independent approach to the communication of distributed objects. It uses entities, called Object Request Brokers (ORB), to transmit requests from the client to the server, and return the results from the request back to the client. These ORBs must support the Object by Value and Java to IDL mapping CORBA standards. By imposing those standards and introducing Interface Definition Language (IDL), CORBA provides interoperability between ORB implementations from different vendors.

The RMI-IIOP framework actually brings together those interoperability features of CORBA and the ease-of-use features of RMI.

The RMI-IIOP functions are logically concentrated into the J2EE Engine’s IIOP Provider Service.

RMI-IIOP Objects Communication

The process of communication between the client and the server parts of an RMI-IIOP application is similar to that of RMI-P4 objects. The client obtains a reference to the server-side object and calls remote methods on it. The call is transmitted by the IIOP protocol. RMI-IIOP uses stubs and ties to facilitate remote communication between the remote objects.

Remote Objects Communication in RMI-IIOP

Definition of RMI-IIOP Stubs and Ties

The stub is a class that extends javax.rmi.CORBA.Stub and implements the remote interface. A tie is a class that extends org.omg.CORBA_2_3.portableObjectImpl and implements javax.rmi.CORBA.Tie. The stub is the implementation of the interface that is passed to the client, and the tie is the server-side class. Both classes facilitate communication between the client and the server-side object.