• extends package java.rmi.Remote
• provide all methods to be called remotely
• each methods must through a remote exception

import java.rmi.*;
 
public interface ServerInterface extends Remote {
     public void method1() throws RemoteException;
     public int method2() throws RemoteException;
     // ...
}

2. Write Server Class

• implements RMI-Server Interface
• extends UnicastRemoteObject (at least for simple RMI)
• Constructor throws java.rmi.RemoteException
• must be registered at local registry

 
import java.rmi.*;
import java.net.MalformedURLExcpetion;
import java.rmi.registry.*;
import java.rmi.server.UnicastRemoteObject;
 
public class MyServer extends UnicastRemoteObject implements ServerInterface {
 
  MyServer() throws RemoteException {
    super();
  }
 
  public static void main(String[] args) {

    try {
      LocateRegistry.createRegistry(Registry.REGISTRY_PORT);
    } catch (RemoteException ex) {
      System.out.println(ex.getMessage());
    }
    try {
      Naming.rebind("MyServer", new MyServer());
    } catch (MalformedURLException ex) {
      System.out.println(ex.getMessage());
    }
    catch (RemoteException ex) {
      System.out.println(ex.getMessage());
    }
  }
  // ...
}

3. Write a client

• get remote reference
• call remote methods
• be careful with rmi-specific problems (a more detailed tutorial will explain to you)

// any class, ...
// url expects String in url format (e.g. http://127.0.0.1/MyServer for local testing)
 
try {
      ServerInterface server = (ServerInterface) Naming.lookup(url);
      server.method1();
      int calculated_by_server = server.method2();
      // ...
} catch (Exception ex) {

}

• RMI: Remote API, UnicastRemoteObject API, Registry API, LocateRegistry API
• Properties: Properties API
• IO: IO Package API

• Networking Basics: Short explanation of networking basics like TCP, UDP and ports.
• Java IO Tutorial: It's absolutely necessary to be familiar with I/O and streams to do sockets operations!
• Java TCP Sockets Tutorial: A very useful introduction to (TCP) sockets programming.
• Java Datagrams Tutorial: Provides all the information you need to send and receive datagram packets using UDP.
• Java Concurrency Tutorial: A tutorial about concurrency that covers threads, thread-pools and synchronization.
• Java Programmierhandbuch und Referenz - Section 13.2.3: German tutorial for using datagram sockets. (optional)

Important Java-API Classes:

• IO: IO Package API
• Concurrency: Thread API, Runnable API, ExecutorService API, Executors API
• Java TCP Sockets: ServerSocket API, Socket API
• Java Datagrams: DatagramSocket API, DatagramPacket API

2. Learning RMI

• Java RMI Tutorial: A short introduction into RMI.
• JGuru RMI Tutorial: A more detailed tutorial about RMI.
• JavaInsel RMI Tutorial: German introduction into RMI programming. (optional)

Important Java-API Classes:

• RMI: Remote API, UnicastRemoteObject API, Registry API, LocateRegistry API
• Properties: Properties API
• IO: IO Package API

3. Security

• Chapter 9 - Security from the book Distributed Systems: Principles and Paradigms (2nd edition)
• Java Cryptography Architecture (JCA) Reference Guide: Tutorial about the Java Cryptography Architecture (JCA)
• Handbook of Applied Cryptography (free version) (optional)

Important Java-API Classes:

• Java SE 6: Cipher, SecureRandom, and Signature classes
• Bouncy Castle: PEMReader and Base64