Re: Strange problem looks even stranger

> I ran the program with option -verbose to see which classes are loaded.
> More than 700 classes are loaded, which is already a surprise for me.
>
> Among all those lines reporting loads, I find:
>
>     [Loaded rmisrv.I_Srv from http://localhost:8080/]
>
> which confirms that the interface for the remote object is loaded (previously, I only saw that it was
> sent by the server)
>
> And my program terminates with:
>
>      Exception in thread "main" java.lang.NoClassDefFoundError: rmisrv/I_Srv
>         at rmicli.Cli.main(Cli.java:15)

I can't say for sure from the information that you have provided so
far, but if I gather correctly that "rmisrv.I_srv" is a remote
interface and "rmicli.Cli" is your client program, I suspect that you
are incorrectly assuming that the remote interface, to which the
client program is directly linked, can be dynamically downloaded to
the client, as opposed to bundled with or installed with the client
program.

In other words, I suspect that the successful loading of the interface
from http://localhost:8080/ that you see in the -verbose output occurs
when the stub for the remote object is unmarshalled, which completes
successfully.  The NoClassDefFoundError then occurs when your client
program attempts to cast the unmarshalled stub to the interface type,
which happens to trigger lazy resolution of the client program's
symbolic reference to that type-- which fails with a
NoClassDefFoundError (a kind of LinkageError) because the client
program's defining class loader cannot load the interface (even though
the RMI class loader for the codebase could).

This incorrect assumption is a common misunderstanding-- see this
previous post and others linked from it:

http://archives.java.sun.com/cgi-bin/wa?A2=ind0510&L=rmi-users&P=1536

Again, this explanation is just a guess based on the information that
you have provided so far.

-- Peter

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