Code for CONCEPT of RMI

Hello.java

Code :

import java.rmi.Remote;

import java.rmi.RemoteException;

// Remote interface

public interface Hello extends Remote {

    // Remote method declaration

    String sayHello() throws RemoteException;

}

HelloImpl.java

Code:

import java.rmi.RemoteException;

import java.rmi.server.UnicastRemoteObject;

// Remote object implementation

public class HelloImpl extends UnicastRemoteObject implements Hello {

    // Constructor (needed to throw RemoteException)

    public HelloImpl() throws RemoteException {

        super();

    }

    // Implementation of the remote method

    public String sayHello() throws RemoteException {

        return "Hello, Remote World!";

    }

}

HelloServer.java

Code:

import java.rmi.registry.LocateRegistry;

import java.rmi.registry.Registry;

public class HelloServer {

    public static void main(String[] args) {

        try {

            // Create and export a remote object instance

            HelloImpl helloObj = new HelloImpl();

            // Get RMI registry on port 1099 (default)

            Registry registry = LocateRegistry.createRegistry(6677ja);

            // Bind the remote object's stub in the registry

            registry.rebind("HelloService", helloObj);

            System.out.println("Server is ready...");

        } catch (Exception e) {

            System.err.println("Server exception: " + e.toString());

            e.printStackTrace();

        }

    }

}

HelloClient.java

Code:

import java.rmi.registry.LocateRegistry;

import java.rmi.registry.Registry;

public class HelloClient {

    public static void main(String[] args) {

        try {

            // Get RMI registry on localhost, port 1099

            Registry registry = LocateRegistry.getRegistry("localhost", 6677);

            // Look up the remote object by the name

            Hello helloObj = (Hello) registry.lookup("HelloService");

            // Invoke the remote method

            String response = helloObj.sayHello();

            System.out.println("Response from Server: " + response);

        } catch (Exception e) {

            System.err.println("Client exception: " + e.toString());

            e.printStackTrace();

        }

    }

}

Note: For it You have to Start the RMI registry (in a separate terminal or command prompt) using command : 

start rmiregistry

Output: