RMI observer problem

Question

Hello
I want to write a client server application using rmi and eclipse, where many clients are able to register to the server. The server has a string attribute and a client should be able to pass a string object to the server and the server replaces the value of his attribute with the sent string and notifies all registered clients of the new value. In a later step the server writes to a mysql database and notifies the clients about changes in the database, but that is later...
I use eclipse for developing.
Here is the remoteinterface of the server:
package com.iz.rmi.server;
import java.rmi.*;
import java.rmi.server.*;
import com.iz.rmi.client.IObserver;
public interface ISubject extends Remote
     public void registerClient(IObserver obs) throws RemoteException, ServerNotActiveException;
     public void notifyObervers() throws RemoteException, ServerNotActiveException;
} the remoteinterface of the client:
package com.iz.rmi.client;
import java.rmi.*;
import java.rmi.server.*;
public interface IObserver extends Remote
     public void sendNotify(String notification) throws RemoteException, ServerNotActiveException;
}the implementation of the server interface:
package com.iz.rmi.server;
import java.net.MalformedURLException;
import java.rmi.*;
import java.rmi.server.*;
import java.rmi.registry.*;
import java.util.*;
import com.iz.rmi.client.*;
public class Subject extends UnicastRemoteObject implements ISubject
     private Vector<IObserver> obs;
     private String service;
     public Subject() throws java.rmi.RemoteException
          super();
          this.obs = new Vector<IObserver>();
     @Override
     public void notifyObervers() throws RemoteException, ServerNotActiveException
          Iterator<IObserver> obsIt = this.obs.iterator();
          while(obsIt.hasNext())
               IObserver o = obsIt.next();
               try
                    o.sendNotify("blabla");
               catch (Exception e)
                    e.printStackTrace();
     @Override
     public void registerClient(IObserver obs) throws RemoteException, ServerNotActiveException
          System.out.println("client registered");
          this.obs.add(obs);
     public static void main(String[] args)
          if (System.getSecurityManager() == null)
            System.setSecurityManager(new SecurityManager());
          try
            String name = "Observable";
            ISubject engine = new Subject();
            //ISubject stub = (ISubject) UnicastRemoteObject.exportObject(engine, 0);
            LocateRegistry.createRegistry(1099);
            Registry registry = LocateRegistry.getRegistry(1099);
            registry.rebind(name, engine);
            System.out.println("ComputeEngine boundlll");
          catch (Exception e)
            System.err.println("ComputeEngine exception:");
            e.printStackTrace();
} and the implementation of the client interface
package com.iz.rmi.client;
import java.rmi.*;
import java.rmi.server.*;
import com.iz.rmi.server.*;
public class Observer extends UnicastRemoteObject implements IObserver
     private String host;
     private String service;
     private ISubject sub;
     public Observer(String host, String service) throws RemoteException
          this.host = host;
          this.service = service;
          System.out.println("Service: " + service);
          try
               this.sub = (ISubject) Naming.lookup(this.service);
               this.sub.registerClient(this);
               System.out.println(" istered");
          catch(Exception e)
               System.out.println("Unable to connect and register with subject.");
               e.printStackTrace();
     @Override
     public void sendNotify(String notification) throws RemoteException,
               ServerNotActiveException
     public static void main(String[] args)
          try {
               new Observer("192.168.1.34:1099", "Observable");
          } catch (RemoteException e) {
               // TODO Auto-generated catch block
               e.printStackTrace();
}Both programs get started with this vm-argument:
-Djava.security.policy=C:\daten\noSpring\Obsv\wideopen.policy
where wideopen.policy looks like this for testing:
grant {
     // Allow everything for now
     permission java.security.AllPermission;
};when I start the server all looks fine, but when I start the a client i become just the output.
Service: Observable
isteredinstead of
Service: Observable
client registerd
isteredThere are no exceptions or something like that, but it seems that the registerClient()-method does not get called on the server when the client starts. There were many changes since the last time I used rmi, so I don't know what's wrong here. I hope some one can help me with this problem.
Kind regards,
Michael

Answer 1

The server's System.out.prints will go to the server's console on the server host.
Not interleaved wih the client's output on the client's console on the client host.