RMI Example

The interface: (FarOutDate.java)

   import java.rmi.*;
   import java.util.*;

   public interface FarOutDate extends Remote {
      Date getDate() throws RemoteException;
   }

The Server: (DateServer.java)

   import java.util.*;
   import java.rmi.*;
   import java.rmi.server.*;

   public class DateServer {
      public static void main (String args[]) {
         System.setSecurityManager(new RMISecurityManager());
         try {
            FarOutDate date_server = new DateImpl();
            Naming.rebind("DateServer", date_server);
            System.out.println("DateServer serving");
         }
         catch (Exception e) {
            System.out.println(e.toString());
         }
      }
   }

The Implemented Classes: (DateImpl.java)

   import java.util.*;
   import java.rmi.*;
   import java.rmi.server.*;

   public class DateImpl extends UnicastRemoteObject implements FarOutDate {
      public DateImpl () throws RemoteException { }
   
      public Date getDate() throws RemoteException {
         return new Date();
      }
   }

A Simple Client: (FarOutDateClient.java)

   import java.rmi.*;
   import java.awt.*;
   import java.awt.event.*;
	import java.applet.*;
	import javax.swing.*;

   public class FarOutDateClient extends Applet implements ActionListener {
      JTextField text;
      JButton getit;
      JTextArea area;
   
      public void init () {
         setLayout(new BorderLayout(10,10));
         add ("North", text = new JTextField());
         add ("Center", new JScrollPane(area = new JTextArea()));
         Panel p = new Panel();
         p.setLayout(new GridLayout(1,3));
         p.add(new Label());
         p.add(getit = Jnew Button("Get Date"));
         add ("South", p);
      }
   
      public void start () {
         getit.addActionListener(this);
      }

      public void actionPerformed (ActionEvent evt) {
         if (evt.getSource() == getit) {
            try {
               String server_object = "rmi://localhost/DateServer";
               FarOutDate date = (FarOutDate)Naming.lookup(server_object);
               area.append(date.getDate()+"\n");
            }
            catch (Exception e) {
               text.setText(e.toString());
            }
         }
      }
   }

HTML file to start the client: (date.html)

   < applet code="FarOutDateClient.class" width=300 height=350 >
   < /applet >

Instructions:

1. Edit and compile the code above in "home" directory
2. Run "rmic DateImpl"
3. Transfer non-client classes to /usr/local/java/lib
4. Run "rmiregistry &"
5. From /usr/local/java/lib run "java DateServer"
6. Wait for "DateServer serving"
7. From "home" directory run "appletviewer date.html"