RMI - ClassCastException - Proxy cannot be cast

Hello, i'm currently switching to RMI for networking in my application, i have followed some tutorials, read some on Oracles RMI pages and i belive i understand the concept behind it.

I found a example on the net and its working with transmitting Strings. however when i try to send my own object it get the error:

Code:

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HelloClient exception: java.lang.ClassCastException: sun.proxy.$Proxy0 cannot be cast to saqib.rasul.server.Fag
java.lang.ClassCastException: sun.proxy.$Proxy0 cannot be cast to saqib.rasul.server.Fag
        at sun.proxy.$Proxy0.returnFag(Unknown Source)
        at saqib.rasul.server.dd.main(dd.java:19)

---

Googling for this error tells me from what i can understand that i have not implemented the interface in my class. But i have (Fag implements FagInterface).

So yeh, i have no idea why i get this error, and what it means.

Client.java

Code:

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package saqib.rasul.server;

import java.rmi.Naming;



public class Client {
          /**
          * Client program for the "Hello, world!" example.
          * @param argv The command line arguments which are ignored.
          */
          public static void main (String[] argv) {
            try {
          //  HelloInterface hello = (HelloInterface) Naming.lookup ("//localhost/Hello");
              FagInterface fag = (FagInterface) Naming.lookup("//localhost/Fag");

             
            // System.out.println (hello.say());
              System.out.println(fag.returnFag());
            } catch (Exception e) {
              System.out.println ("HelloClient exception: " + e);
              e.printStackTrace();
            }
          }
}

---

Breaks on: System.out.println(fag.returnFag());

Server.java

Code:

---

package saqib.rasul.server;

import java.rmi.registry.LocateRegistry;
import java.rmi.registry.Registry;
import java.rmi.server.UnicastRemoteObject;

public class Server {
        /**
        * Server program for the "Hello, world!" example.
        * @param argv The command line arguments which are ignored.
        */
        public static void main (String[] argv) {
                try {
                        java.rmi.registry.LocateRegistry.createRegistry(1099);
                        System.out.println("RMI registry ready.");
                        //Naming.rebind ("Hello", new Hello ("Hello, world!"));
         
                        String name = "Fag";
            FagInterface engine = new Fag("Universi");
            FagInterface stub =
                (FagInterface) UnicastRemoteObject.exportObject(engine, 0);
            Registry registry = LocateRegistry.getRegistry();
            registry.rebind(name, stub);
                       
                        System.out.println ("Hello Server is ready.");
                } catch (Exception e) {
                        System.out.println ("Hello Server failed: " + e);
                }
        }
}

---

FagInterface.java

Code:

---

package saqib.rasul.server;

import java.rmi.Remote;
import java.rmi.RemoteException;

public interface FagInterface extends Remote{

        public Fag returnFag() throws RemoteException;
       
       
}

---

Fag.java

Code:

---

package saqib.rasul.server;

import java.rmi.RemoteException;
import java.rmi.server.UnicastRemoteObject;
import java.util.ArrayList;

/**
 *
 * @author Per-Arne
 * @description Simple class which contains all subjects (fag) in a single course (kurs). The way this class works is that it takes a ArrayList with subject for a whole week. Then this week is added to another ArrayList which then is the grand total of subjects.
 */
public class Fag implements FagInterface{
        private static final long serialVersionUID = 1L;
        public String fagName;
        public ArrayList<ArrayList<FagTime>> weeks;
        private Fag fag;

        public Fag(String fagName) throws RemoteException{
                this.fag = this;
        }

        /**
        * @param week - Contains a whole week with subjectData, this is added to this course.
        */
        public void addWeek(ArrayList<FagTime> week) throws RemoteException{
                weeks.add(week);
        }

        public Fag returnFag() throws RemoteException {
                return fag;
        }               
}

---

Thanks
Driiper

Figured it out...

I had to use the same package name (Which makes sense)