Developing a Jini Service by Gopalan Suresh Raj

This simple Jini service returns the current time in milliseconds when it's getTime() method in invoked.

MyServer.java

import net.jini.core.entry.*;
import net.jini.core.lookup.*;
import net.jini.core.discovery.*;
import net.jini.lookup.entry.*;
import net.jini.discovery.*;
import com.sun.jini.lookup.*;
import com.sun.jini.lease.*;

import java.io.*;
import java.rmi.*;
import java.rmi.server.*;

/***************************************************************************

MyServer -- The Jini Server Class

***************************************************************************/

public class MyServer extends UnicastRemoteObject
implements MyServerInterface, ServiceIDListener, Serializable {

public MyServer() throws RemoteException { super (); }

public long getTime() throws RemoteException { // MyServiceInterface
System.out.println ("====================================================");
System.out.println ("MyServer: The method getTime() in MyServer was called");
long serverTime = System.currentTimeMillis();
System.out.println ("MyServer: Time at server is " + serverTime + " msecs");
System.out.println ("====================================================");
return(serverTime);
}

public void serviceIDNotify (ServiceID serviceId) { } // ServiceIDListener

public static void main (String[] args) {
int i;
int iPort;
String sHost;
MyServer myServer;
LookupLocator lookup;
Entry[] aeAttributes;
JoinManager joinmanager;
ServiceID id;
ServiceMatches matches;
ServiceRegistrar registrar;

try {
   /*
   Setting the security manager to allow the RMI class loader
   to go to the codebase for classes that are not available
   locally.
   ========================================================== */
   System.setSecurityManager (new RMISecurityManager ());

   /*
   Create the attributes (an array of entry objects) that describe
   this server and use it to register this server with the lookup
   service. JoinManager finds and registers with the lookup
   service.
   =============================================================== */
   aeAttributes = new Entry[1];
   aeAttributes[0] = new Name("MyServer");
   myServer = new MyServer();
   joinmanager = new JoinManager(myServer,aeAttributes,myServer,new LeaseRenewalManager());
   System.out.println("MyServer: JoinManager = " + joinmanager);

   /*
   Find the Jini lookup service (reggie) and print its location.
   ============================================================= */
   lookup = new LookupLocator ("jini://localhost");
   sHost = lookup.getHost ();
   iPort = lookup.getPort ();
   System.out.println ("MyServer: LookupLocator = " + lookup);
   System.out.println ("MyServer: LookupLocator.host = " + sHost);
   System.out.println ("MyServer: LookupLocator.port = " + iPort);

   /*
   Get the lookup service's ServiceRegistrar (the class by which
   interaction with the lookup service is possible).
   ============================================================= */
   registrar = lookup.getRegistrar();
   id = registrar.getServiceID ();
   System.out.println ("MyServer: ServiceRegistrar = " + registrar);
   System.out.println ("MyServer: ServiceID = " + id);

   /*
   Itemize the service items and the service objects that are
   available in the lookup service. Note: Sometimes this is
   executed too quickly for the service that was registered above
   to show up.
   ============================================================== */
   try {Thread.sleep (2000);} catch (Exception e) {}

   matches = registrar.lookup(new ServiceTemplate (null, null, null),50);
   System.out.println ("MyServer: ServiceMatches = " + matches);
   System.out.println ("MyServer: num matches = "+ matches.totalMatches);
   for (i = 0; i < matches.totalMatches; i++) {
    System.out.println ("MyServer: svc item " + i + ": " + matches.items[i]);
    System.out.println ("MyServer: svc object " + i + ": "+ matches.items[i].service);
   }
   System.out.println ("*-----------------------------------------*");
} catch (Exception e) { System.out.println("MyServer: MyServer.main(): Exception " + e); }
}
}