The Distributed Object Model 

Use

The distributed applications consist of two parts: a client part and a server part. A typical server part of such an application defines several distributed objects and allows clients to request them by obtaining references to them. The client part obtains a reference to one or more objects from the server part, and calls their methods. RMI-P4 provides the mechanism by which client and server parts communicate.

Features

The RMI-P4 implements the following functions that an application based on the Distributed Object Model requires:

●      Locate the distributed object

You can obtain references to a distributed object in your application using one of the following two options: either by registering the distributed objects to a naming system, or by sending distributed objects as parameters or return values of methods. The RMI-P4 does not use the standard RMI registry; it uses the AS Java’s Naming System (which is a JNDI implementation) to obtain an initial reference to the distributed object instead.

●      Communicate with the distributed object

The details of the actual communication are hidden behind the implementation of the P4 protocol. From a programming point of view, this communication does not differ from the standard local method invocation.

●      Load classes of objects that are transmitted in the communication process

To reduce the size of standalone applications and to make sure they do not use outdated class versions, the RMI-P4 can download missing classes from the AS Java cluster.