EJB3 Stateful:ClassCastException when casting the object returned in lookup

Hi,
I'm developing a web application that make use of EJB3 stateless and stateful beans. The application server is the Websphere Application Server 6.1.0.15 with the EJB3 Feature Pack installed and the web server is the IBM HTTP Server running in another machine.
The problem I'm facing is that for every stateful bean after the lookup, it throws a ClassCastExcption when casting the object returned. See part of the log below.
[7/13/08 3:15:48:869 CDT] 0000001c SystemErr R java.lang.ClassCastException: cannot cast class com.spcs.dsa.ejb.authenticationmanager._AuthenticationManager_Stub to class com.spcs.dsa.ejb.authenticationmanager._AuthenticationManager_Stub
at com.ibm.rmi.javax.rmi.PortableRemoteObject.narrow(PortableRemoteObject.java:396)
at com.spcs.dsa.ejb.client.DsaEjbClient.getAuthenticationRemote(DsaEjbClient.java:37)
at com.spcs.dsa.action.NewCardAction.execute(NewCardAction.java:85)
at sun.reflect.NativeMethodAccessorImpl.invoke0(Native Method)
at sun.reflect.NativeMethodAccessorImpl.invoke(NativeMethodAccessorImpl.java:39)
at sun.reflect.DelegatingMethodAccessorImpl.invoke(DelegatingMethodAccessorImpl.java:25)
at java.lang.reflect.Method.invoke(Method.java:585)
Please notice in the log above that the cast was done for the correct class.
Here is the java code:
AuthenticationManager auth =
(AuthenticationManager) javax.rmi.PortableRemoteObject.narrow(
context.lookup("com.spcs.dsa.ejb.authenticationmanager.AuthenticationManager"),
AuthenticationManagerStub.class);
This problem doesn't happen for statless beans. If you simply change the class to be stateless, this problem stop to happen.
If you run this code in a stand alone program, this problem doesn't happen. It only happen when running in the web server.
Does anybody know what should be done to solve this problem ??
Thanks,
Marcos.

I'm not familiar with any specifics of IBM's implementation but from an EJB 3 spec perspective there is no need to use PortableRemoteObject.narrow() if you're retrieving an EJB 3.0 Remote Business interface, regardless of the component type( stateful vs. stateless). In addition, the "_Stub" class should never have to be part of your client programming model. That should be hidden within the vendor's implementation, if present at all.
If AuthenticationManager is the Remote 3.0 Business Interface
@Remote
public interface AuthenticationManager {
your client lookup should be :
AuthenticationManager am = (AuthenticationManager) context.lookup("...");

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Hope this helps you.
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"jian zhang" <[email protected]> wrote in message
news:[email protected]...
>
I am using weblogic 5.1 with service pack 10.
I need to query pdf data stored in a blob field in Oracle
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wish to make your programming efforts lest cast intensive.

For those having problems with 10.4.x, try this link and see if any of their fixes address your problems. Apparently, there are several issues with
10.4.x that are unrelated to the fix for the 10.3.9 users that I posted.
Apple Mac OS X Intel - 10.4.9
http://www.macfixit.com/search.php?productID=29147
Apple Mac OS X PPC - 10.4.9
http://www.macfixit.com/search.php?productID=8848

Warning when casting object into generic type at run time.

I am getting this message when casting an object at run time:
Type safety: The cast from Object to Tree<V> is actually checking against the erased type TreeI'm overloading an equals(Object o) method in my class.
Is there a way to get rid of the warning (besides turning the warning off :))

I'm overloading an equals(Object o) method in my
class.
Is there a way to get rid of the warning (besides
turning the warning off :))No. The best you can do is what is demonstrated in the previous link.

ClassCastException when running on invocable task

The following exception has occurred when running a synchronous invocable task, It appears to be internal to Coherence as nowhere in my code am I casting from an Object to a List.
+[2010-03-24 19:14:09.143 +0000] 5945635 [Logger@9264171 3.5.3/465] ERROR Coherence - 2010-03-24 19:14:09.143/5945.921 Oracle Coherence GE 3.5.3/465 <Error> (thread=DistributedCache:default, member=7): An exception occured while dispatching synchronous event:MapListenerSupport$FilterEvent{DistributedCache$BinaryMap inserted: key=Binary(length=4, value=0x02AE9A42), value=null, synthetic, filters=[null]}+
+[2010-03-24 19:14:09.145 +0000] 5945637 [Logger@9264171 3.5.3/465] ERROR Coherence - 2010-03-24 19:14:09.143/5945.921 Oracle Coherence GE 3.5.3/465 <Error> (thread=DistributedCache:default, member=7):+
java.lang.ClassCastException: java.lang.Object cannot be cast to java.util.List
at com.tangosol.net.cache.CachingMap.validate(CachingMap.java:1245)
at com.tangosol.net.cache.CachingMap$BackMapListener.onMapEvent(CachingMap.java:1628)
at com.tangosol.util.MultiplexingMapListener.entryInserted(MultiplexingMapListener.java:33)
at com.tangosol.util.MapEvent.dispatch(MapEvent.java:266)
at com.tangosol.coherence.component.util.daemon.queueProcessor.service.grid.DistributedCache$ViewMap$ProxyListener.dispatch(DistributedCache.CDB:22)
at com.tangosol.coherence.component.util.daemon.queueProcessor.service.grid.DistributedCache$ViewMap$ProxyListener.entryInserted(DistributedCache.CDB:1)
at com.tangosol.util.MapListenerSupport$WrapperSynchronousListener.entryInserted(MapListenerSupport.java:856)
at com.tangosol.util.MapEvent.dispatch(MapEvent.java:266)
at com.tangosol.coherence.component.util.CacheEvent.dispatchSafe(CacheEvent.CDB:14)
at com.tangosol.coherence.component.util.daemon.queueProcessor.service.grid.DistributedCache$BinaryMap.dispatch(DistributedCache.CDB:86)
at com.tangosol.coherence.component.util.daemon.queueProcessor.service.grid.DistributedCache.onMapEvent(DistributedCache.CDB:43)
at com.tangosol.coherence.component.util.daemon.queueProcessor.service.grid.DistributedCache$MapEvent.onReceived(DistributedCache.CDB:3)
at com.tangosol.coherence.component.util.daemon.queueProcessor.service.Grid.onMessage(Grid.CDB:9)
at com.tangosol.coherence.component.util.daemon.queueProcessor.service.Grid.onNotify(Grid.CDB:136)
at com.tangosol.coherence.component.util.daemon.queueProcessor.service.grid.DistributedCache.onNotify(DistributedCache.CDB:3)
at com.tangosol.coherence.component.util.Daemon.run(Daemon.CDB:42)
at java.lang.Thread.run(Unknown Source)
+[2010-03-24 19:14:09.145 +0000] 5945637 [Logger@9264171 3.5.3/465] ERROR Coherence - 2010-03-24 19:14:09.143/5945.921 Oracle Coherence GE 3.5.3/465 <Error> (thread=DistributedCache:default, member=7): (The exception has been logged and execution is continuing.)
The Object returned by the getResult() method of the Invocable is a Map so I really don't see where the List cast is coming from.
Any Ideas?

We have reported the same issue to Coherence support. This started happening in production when we switched to 3.5.3. In fact we get 3 exceptions together.
2010-07-02 05:54:33.477/316855.583 Oracle Coherence GE 3.5.3/465 <Error> (thread=DistributedCache:DefaultDistributedCache, member=4): (The exception has been logged and execution is continuing.)
2010-07-02 05:54:33.477/316855.583 Oracle Coherence GE 3.5.3/465 <Error> (thread=DistributedCache:DefaultDistributedCache, member=4):
2010-07-02 05:54:33.477/316855.583 Oracle Coherence GE 3.5.3/465 <Error> (thread=DistributedCache:DefaultDistributedCache, member=4): An exception occured while dispatching synchronous event:MapListenerSupport$FilterEvent{DistributedCache$BinaryMap updated: key=Binary(length=31, value=0x061D656E67696E654865617274626561744F7574626F756E64576F726B6572), old value=null, new value=null, filters=[null]}

EJB3 Stateful:ClassCastException when casting the object returned in lookup

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