Re: Web Start & RMI (Stub Class not found)

"Andrew Thompson" <>
5 Sep 2006 08:16:26 -0700
<> wrote:

Andrew Thompson wrote: wrote:

I have a client application that uses RMI and works fine. However when
run as a WebStart application it throws a ClassNotFound exception when
it tries to get a handle on a remote stub from the server.

The code I use is

Registry registry = LocateRegistry.getRegistry("localhost", 1234);
// lookup the factory
universe = (IMyFactory) registry.lookup("rmi:///MyManagerFactory");

It throws the exception on the lookup.

The CNFE is occuring for the 'IMyFactory', I take it?

Caused by: java.lang.ClassNotFoundException:


The last line of the code should have read :

niverse = (IMyFactory) registry.lookup("rmi:///MyFactory");

Tthe IMyFactory class is in a jar file know to the client via the jnlp
called IServer.jar however MyFactory and MyFactory_stub classes are in
a jar file called Server.jar and is not available to the client but is
to the server.

The only reason I can think that MyFactory_Stub
causes an excpetion at that line is if IMyFactory
inherits from it - does it?

In any case, if a class is referenced in any sense in a
client-side application, it needs to be *available* to the

Any ideas at all ?

- State error output verbatim.
- Tell us what Jar the IMyFactory is supposed to reside in.
- Check it is in there.
- Show us your JNLP (or better still, link to it).

Sorry should have put extra details in the original email.

Cool. But note that a post to a usenet newsgroup is a
very different thing to email. Email is not public, not
publicly searchable - and would cost you a lot more. ;-)

The jnlp is : (cut out some none relevant info)

OK.. Normally I tell people to be wary of trimming
details, on the basis that "if you don't know what is
failing. it is hard to identify the relevant parts of the
problem" but your trimming of both the stack trace and
JNLP was a good call. I *think* I have enough details..

To cut to..

<?xml version="1.0" encoding="UTF-8"?>

    <j2se version="1.4" max-heap-size="256m" initial-heap-size="32m">
    <jar href="MyApp.jar">
    <jar href="IServer.jar">

...(1) so your <resources> section must include the Jar that
contains 'MyFactory_Stub'. 'Server.jar' must be included here.

I'm not sure if I need to setup a codebase or any other config for
webstart when using RMI that perhaps isn't required for a normal client

No. WebStart works the same as native applications and
applets in that respect. I suspect the thing that is complicating
matters here, is that somehow the desktop application already
has access to the 'Server.jar'.

Andrew T.

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