RMI Architecture

RMI system allows an object running in one JVM to invoke methods on an object in another JVM. RMI can communicate only between programs written in Java.

RMI applications often consist of two applications:

a server and
a client

The application is divided into objects. A server creates remote objects and registers these objects with a simple bootstrap name server called a registry (rmiregistry). The client gets a handle by looking up the remote object by its name in the server(s) registry and invokes methods on it.

Every distributed system is built on the top of a network, so network is an essential part of all these systems.

Remote object

A remote object is one whose methods can be invoked from another JVM practically on a different machine. In situations where you do not have a network, or a client, or a server available to test programs, you can invoke methods on a remote object from another JVM on the same machine. A remote object must implement at least one interface that extends the java.rmi.Remote interface.

Remote Interface

A remote interface is an interface, which declares a set of methods that may be invoked remotely (from a different JVM). All interactions with the remote object will be performed through this interface. A remote interface must directly or indirectly extend the java.rmi.Remote interface. Each method declaration in a remote interface must include java.rmi.RemoteException or one of its superclasses in its throws clause.