The following classes implement a simple client-server program using RMI that displays a message. Before running this example, we need to make a 'stub' file for the interface we used. For this task we have the RMI compiler - 'rmic' Note: we make a stub file from the '*.class' file with the implementation of the remote interface, not from the '*.…

RmiClient.java

import java.rmi.Naming;
 
public class RmiClient { 
    public static void main(String args[]) throws Exception {
        RmiServerIntf obj = (RmiServerIntf)Naming.lookup("//localhost/RmiServer");
        System.out.println(obj.getMessage()); 
    }
}

RmiServer.java

import java.rmi.Naming;
import java.rmi.RemoteException;
import java.rmi.server.UnicastRemoteObject;
import java.rmi.registry.*; 
public class RmiServer
    extends UnicastRemoteObject 
    implements RmiServerIntf {
    public static final String MESSAGE = "Hello World";
 
    public RmiServer() throws RemoteException {
        super(0);    // required to avoid the 'rmic' step, see below
    }
 
    public String getMessage() {
        return MESSAGE;
    }
 
    public static void main(String args[]) throws Exception {
        System.out.println("RMI server started");
 
        try { //special exception handler for registry creation
            LocateRegistry.createRegistry(1099); 
            System.out.println("java RMI registry created.");
        } catch (RemoteException e) {
            //do nothing, error means registry already exists
            System.out.println("java RMI registry already exists.");
        }
 
        //Instantiate RmiServer
 
        RmiServer obj = new RmiServer();
 
        // Bind this object instance to the name "RmiServer"
        Naming.rebind("//localhost/RmiServer", obj);
        System.out.println("PeerServer bound in registry");
    }
}

RmiServerIntf.java

import java.rmi.Remote;
import java.rmi.RemoteException;
 
public interface RmiServerIntf extends Remote {
    public String getMessage() throws RemoteException;
}