RMI - getting ClassNotFoundException for my remote interface

[Swiftslide]

I'm going through the tutorial at Getting Started Using Java RMI . Reason is that I am having great problems running an application of my own that uses RMI. I thought I'd go back to basics and see if I could work out what's wrong.
And lo and behold, I can't get the tutorial to run, either!
That's not entirely true: I have got it to run once. Silly me, I didn't record what I did to make it run, and can't replicate this momentous feat.

Anyway...

The tutorial includes all the code: I have written none of it, edited none of it, so for once I cannot be blamed for bad coding. I am trying to get the server class to run. The code is:

package example.hello;
	
import java.rmi.registry.Registry;
import java.rmi.registry.LocateRegistry;
import java.rmi.RemoteException;
import java.rmi.server.UnicastRemoteObject;
	
public class Server implements Hello {
	
    public Server() {}

    public String sayHello() {
	return "Hello, world!";
    }
	
    public static void main(String args[]) {
	
	try {
	    Server obj = new Server();
	    Hello stub = (Hello) UnicastRemoteObject.exportObject(obj, 0);

	    // Bind the remote object's stub in the registry
	    Registry registry = LocateRegistry.getRegistry();
	    registry.bind("Hello", stub);

	    System.err.println("Server ready");
	} catch (Exception e) {
	    System.err.println("Server exception: " + e.toString());
	    e.printStackTrace();
	}
    }
}

The code for the "Hello" interface is simply:

package example.hello;

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

public interface Hello extends Remote {
    String sayHello() throws RemoteException;
}

I keep all this in a file on my desktop (makes for short URIs):

C:\Users\Benji\Desktop\hello

Therefore the three .class files, when compiled, are located in:

C:\Users\Benji\Desktop\hello\example\hello

I first start the RMI registry at the command line, using

start rmiregistry

Then I execute a batch file located in C:\Users\Benji\Desktop\hello, which has the following lines:

java -classpath C:\Users\Benji\Desktop\hello example.hello.Server
pause

I have also tried executing from the command line, by doing:

cd C:\Users\Benji\Desktop\hello

And then:

java -classpath . example.hello.Server

Whatever method I use, I (almost) inevitably am met with the following bog of errors:

Server exception: java.rmi.ServerException: RemoteException occurred in server t
hread; nested exception is:
        java.rmi.UnmarshalException: error unmarshalling arguments; nested excep
tion is:
        java.lang.ClassNotFoundException: example.hello.Hello
java.rmi.ServerException: RemoteException occurred in server thread; nested exce
ption is:
        java.rmi.UnmarshalException: error unmarshalling arguments; nested excep
tion is:
        java.lang.ClassNotFoundException: example.hello.Hello
        at sun.rmi.server.UnicastServerRef.oldDispatch(UnicastServerRef.java:396
)
        at sun.rmi.server.UnicastServerRef.dispatch(UnicastServerRef.java:250)
        at sun.rmi.transport.Transport$1.run(Transport.java:159)
        at java.security.AccessController.doPrivileged(Native Method)
        at sun.rmi.transport.Transport.serviceCall(Transport.java:155)
        at sun.rmi.transport.tcp.TCPTransport.handleMessages(TCPTransport.java:5
35)
        at sun.rmi.transport.tcp.TCPTransport$ConnectionHandler.run0(TCPTranspor
t.java:790)
        at sun.rmi.transport.tcp.TCPTransport$ConnectionHandler.run(TCPTransport
.java:649)
        at java.util.concurrent.ThreadPoolExecutor$Worker.runTask(ThreadPoolExec
utor.java:886)
        at java.util.concurrent.ThreadPoolExecutor$Worker.run(ThreadPoolExecutor
.java:908)
        at java.lang.Thread.run(Thread.java:662)
        at sun.rmi.transport.StreamRemoteCall.exceptionReceivedFromServer(Stream
RemoteCall.java:255)
        at sun.rmi.transport.StreamRemoteCall.executeCall(StreamRemoteCall.java:
233)
        at sun.rmi.server.UnicastRef.invoke(UnicastRef.java:359)
        at sun.rmi.registry.RegistryImpl_Stub.bind(Unknown Source)
        at example.hello.Server.main(Server.java:61)
Caused by: java.rmi.UnmarshalException: error unmarshalling arguments; nested ex
ception is:
        java.lang.ClassNotFoundException: example.hello.Hello
        at sun.rmi.registry.RegistryImpl_Skel.dispatch(Unknown Source)
        at sun.rmi.server.UnicastServerRef.oldDispatch(UnicastServerRef.java:386
)
        at sun.rmi.server.UnicastServerRef.dispatch(UnicastServerRef.java:250)
        at sun.rmi.transport.Transport$1.run(Transport.java:159)
        at java.security.AccessController.doPrivileged(Native Method)
        at sun.rmi.transport.Transport.serviceCall(Transport.java:155)
        at sun.rmi.transport.tcp.TCPTransport.handleMessages(TCPTransport.java:5
35)
        at sun.rmi.transport.tcp.TCPTransport$ConnectionHandler.run0(TCPTranspor
t.java:790)
        at sun.rmi.transport.tcp.TCPTransport$ConnectionHandler.run(TCPTransport
.java:649)
        at java.util.concurrent.ThreadPoolExecutor$Worker.runTask(ThreadPoolExec
utor.java:886)
        at java.util.concurrent.ThreadPoolExecutor$Worker.run(ThreadPoolExecutor
.java:908)
        at java.lang.Thread.run(Thread.java:662)
Caused by: java.lang.ClassNotFoundException: example.hello.Hello
        at java.net.URLClassLoader$1.run(URLClassLoader.java:202)
        at java.security.AccessController.doPrivileged(Native Method)
        at java.net.URLClassLoader.findClass(URLClassLoader.java:190)
        at java.lang.ClassLoader.loadClass(ClassLoader.java:307)
        at java.lang.ClassLoader.loadClass(ClassLoader.java:248)
        at java.lang.Class.forName0(Native Method)
        at java.lang.Class.forName(Class.java:247)
        at sun.rmi.server.LoaderHandler.loadProxyInterfaces(LoaderHandler.java:7
11)
        at sun.rmi.server.LoaderHandler.loadProxyClass(LoaderHandler.java:655)
        at sun.rmi.server.LoaderHandler.loadProxyClass(LoaderHandler.java:592)
        at java.rmi.server.RMIClassLoader$2.loadProxyClass(RMIClassLoader.java:6
28)
        at java.rmi.server.RMIClassLoader.loadProxyClass(RMIClassLoader.java:294
)
        at sun.rmi.server.MarshalInputStream.resolveProxyClass(MarshalInputStrea
m.java:238)
        at java.io.ObjectInputStream.readProxyDesc(ObjectInputStream.java:1530)
        at java.io.ObjectInputStream.readClassDesc(ObjectInputStream.java:1492)
        at java.io.ObjectInputStream.readOrdinaryObject(ObjectInputStream.java:1
731)
        at java.io.ObjectInputStream.readObject0(ObjectInputStream.java:1328)
        at java.io.ObjectInputStream.readObject(ObjectInputStream.java:350)
        ... 12 more

Anyone know what's going on? Pretty please? :eek:

[JosAH]

        java.lang.ClassNotFoundException: example.hello.Hello

Anyone know what's going on? Pretty please? :eek:

Isn't the name of your server example.hello.Server? Also, is that interface Hello.class available at your server?

kind regards,

Jos