java.rmi.ServerException: java .rmi.UnmarshallException

[carox kaur]

After compiling all the java files and generating the stub and skeleton for the remote class when I execute Register.java class that registers and starts the server I get teh error:
java.rmi.ServerException: remote Exception occurred in server thread; nested Exception is :
java .rmi.UnmarshallException :error unmarshallingarguments ; nested exception is:
java.lang.ClassNotFoundException: MyServer_Stub

MyServer_Stub and MyServer_Skel.class files are there.....I am trying to pass the object of a class A that implements Serializable interface, I have tried passing the primitive data types which was successful but this is not working..... Codes are given below if anyone wants to have a look.

RemoteInterface.java

 import java.rmi.*;
import java.rmi.server.*;
//remote object interface

public interface RemoteInterface extends Remote
{
	public void doSomething(A a) throws RemoteException;
	
}

MyServer.java //Class MyServer implements the Remote interface

import java.rmi.*;
import java.rmi.server.*;
//remote object class

public class MyServer extends UnicastRemoteObject implements RemoteInterface
{
	public MyServer() throws RemoteException
	{	
		super();
		System.out.println("This is called");
	}
	public void doSomething(A a)
	{
	System.out.println("The reference of A is "+ a);
	}
}

RegisterServer.java //java file which registers the remote server to directory service

  import java.rmi.*;

class RegisterServer
{
public static void main(String arr[])
{
try{
System.out.println("Creating Remote Object..................");
MyServer server=new MyServer();

System.out.println("Registering........");
Naming.bind("myserver",server);

System.out.println("Remote object is Registered, server is ready........");
}catch(Exception e)
{
	System.out.println(e);
}
}
}  

MyClient.java //client class that sends the remote method invocation

 import java.rmi.*;

class MyClient
{
public static void main(String args[])
{
try{
System.out.println("Performing Lookup.....");
RemoteInterface stub=(RemoteInterface)Naming.lookup("myserver");
System.out.println("reference Obtained....invoking remote methods.....");

A a=new A();

System.out.println("The reference of A is "+ a);
stub.doSomething(a);
}catch(Exception e)
	{
	System.out.println(e);
	}
}
}   

A.java

import java.io.*;

class A implements Serializable
{
A()
{
	System.out.println("A is  initialized");
}
}    

[Nitesh Kant]

How are you starting the rmi registry?
The registry should have your stub class in it's classpath or the server should enable dynamic class downloading.

By the way, if you are on JDK 5 or above you do not need stubs (skeletons are not used since 1.3 i guess). RMI uses dynamic proxies to generate stubs for the remote objects.