Re: A couple of WebLogic specifec questions

Wow, thanks for the quick reply.  I think that you're
right on the money.  I had forgotten that according to
spec, a jvm treats (even byte identical) classes
loaded by different loaders as disparate types.  This
explains the class cast exception.  Still, I'm
suruprised that WebLogic would suffer from this
limitation.  The only work around I can see (other
than throwing them on the system classpath) is to
require my rar to be packaged with each application
rather than stand-alone.  I'll have to try to talk to
someone at BEA.  Thanks again for the input.

-Jason

--- David Jencks <[email protected]> wrote:
> I think the problem is that the copy of the class
> loaded from your war
> is in a different classloader than the copy loaded
> from the .rar.
> Therefore, they are different classes and you get a
> class cast
> exception trying to cast one to the other.  Putting
> the classes in the
> system class path solves this by having both
> classloaders delegate to
> their parent and thus eventually to the system
> classloader: thus you
> get the same class for both.  I recall complaints
> about this when the
> jca spec first came out but I thought WL had come up
> with a solution.
> JBoss solves this kind of problem by having a
> dynamically extensible
> classloader scheme: both the war and rar can be
> loaded separately yet
> their classes are visible to each other.
>
> david jencks
>
> On Sunday, February 16, 2003, at 11:26 PM, Jason
> wrote:
>
> > Hello,
> >
> > First of all, I apoligize if this post is
> off-topic
> > for this list, but I'm trying to deploy my RA into
> > WebLogic and I've run into an issue.
> >
> > I've successfully deployed my RA in WebLogic 7.0
> and
> > added a bit of test code to a jsp to do a lookup
> for a
> > ConnectionFactory and call getConnection( ).  The
> code
> > looks like this:
> >
> > com.mycompany.ConnectionFactory cf =
> >   (com.mycompany.ConnectionFactory)
> > ic.lookup("java:comp/env/MyCtr");
> >
> > cf.getConnection( );
> >
> > The lookup( ) succeeds but I get a class cast
> > exception on the cast to ConnectionFactory.  If I
> > instead just declare the reference to Object and
> then
> > call getClass( .getName( ) I get
> > com.mycompany.ConnectionFactoryImpl just as I'd
> > expect.  Further, if I then use reflection I can
> > verify that the object does in fact implement
> > ConnectionFactory.  However, if I do 'cf
> instanceof
> > ConnectionFactory' it fails which is in agreement
> with
> > the Class Cast Exception.  I've also tried
> 'casting'
> > the ConnectionFactoryImpl to a
> ConnectionFactoryImpl
> > and this also fails.
> >
> > I've included all of the relevent classes in both
> the
> > Deployed Resource adapter (stand alone) as well as
> the
> > classes directory of the war file containing the
> JSP
> > so I can't figure out what's going on.
> >
> > The only way I've found to solve the problem is to
> add
> > the classes to the App Servers ClassPath explictly
> but
> > I'd really rather not do that and in fact
> WebLogic's
> > own documentation discourages it.  Actually, I'm
> > bothered that this solves the problem; since I
> wasn't
> > getting a ClassDefNotFound error, but rather a
> CCE.
> > In any case,   can anyone explain this behavior?
> >
> > -Jason
> >
> >
> >
> > __________________________________________________
> > Do you Yahoo!?
> > Yahoo! Shopping - Send Flowers for Valentine's Day
> > http://shopping.yahoo.com
> >
> >
>
=======================================================================
> > ====
> > To unsubscribe, send email to
> [email protected] and include in the
> > body
> > of the message "signoff CONNECTOR-INTEREST".  For
> general help, send
> > email to
> > [email protected] and include in the body of
> the message "help".
> >
>
>
===========================================================================
> To unsubscribe, send email to [email protected]
> and include in the body
> of the message "signoff CONNECTOR-INTEREST".  For
> general help, send email to
> [email protected] and include in the body of the
> message "help".


__________________________________________________
Do you Yahoo!?
Yahoo! Shopping - Send Flowers for Valentine's Day
http://shopping.yahoo.com

===========================================================================
To unsubscribe, send email to [email protected] and include in the body
of the message "signoff CONNECTOR-INTEREST".  For general help, send email to
[email protected] and include in the body of the message "help".