Can't Cast To Interface?

[nemoannonymous]

I'm trying to build a custom renderer for a Sonic multipartmessage...

public String render(javax.jms.Message msg)
{
stuff
}

msg.getClass() returns "class progress.message.jimpl.xmessage.MultipartMessage"

but if I try casting it to progress.message.jimpl.xmessage.MultipartMessage it crashes, telling me "java.lang.ClassCastException: progress.message.jimpl.xmessage.MultipartMessage cannot be cast to progress.message.jimpl.xmessage.MultipartMessage".

Likewise...

msg.getClass().getInterfaces()[0] returns interface progress.message.jclient.MultipartMessage

But if I try casted it to progress.message.jclient.MultipartMessage I get "ERROR: progress.message.jimpl.xmessage.MultipartMessage cannot be cast to progress.message.jclient.MultipartMessage
>java.lang.ClassCastException: progress.message.jimpl.xmessage.MultipartMessage cannot be cast to progress.message.jclient.MultipartMessage"

How can it simultaneously be, and not be, a given class? What am I overlooking?

Thanks.

Ps-> Here is the declaration of MultipartMessage...

public class progress.message.jimpl.xmessage.MultipartMessage extends progress.message.jimpl.Message implements progress.message.jclient.MultipartMessage

[JosAH]

If you get an "cannot cast X to X" message you've got a classpath problem, i.e.
during runtime you're using an X different from you were using during compile time.

kind regards,

Jos

[nemoannonymous]

Awesome, thanks. Turns out i was loading the one jar twice. I've been struggling with that for two weeks. Big thanks, JosAH.

[JosAH]

Awesome, thanks. Turns out i was loading the one jar twice. I've been struggling with that for two weeks. Big thanks, JosAH.

You're welcome of course but a class is only loaded twice or more when it is
loaded by different classloaders. (or by a very forgetfull classloader) Is your
problem solved now?

kind regards,

Jos