ClassCastException using DestinationService from an EJB

Question

Good morning,
I am running NetWeaver 2004S SP5, and am attempting to make a call to the destination service from within a message-driven bean's onMessage() method.  I can access JNDI and obtain the object returned by doing a JNDI lookup on DestinationService.JNDI_KEY, but when I cast that value to the DestinationService class, I get a ClassCastException.
I have a similar command-line client test program that makes the same call.  It can connect to the destination service and query the named HTTP destination  just fine.
The code I'm using is:
--- begin code snippet ---
DestinationService dstService;
try {
     InitialContext jndiCtx = new InitialContext();
     dstService = (DestinationService)jndiCtx.lookup(DestinationService.JNDI_KEY);
     HTTPDestination dest =
(HTTPDestination)dstService.getDestination("HTTP", "OMSCBUrl");
     urlString = dest.getUrl();
     _logger.logInfo("Retrieved URL(" + urlString + ") from the OMSCB HTTP Destination OMSCBUrl");
} catch (RemoteException re) {
     _logger.logInfo("Unable to contact the destination service : " + re);
} catch (NamingException ne) {
     _logger.logInfo("Unable to contact the JNDI service : " + ne);
} catch (DestinationException de) {
     _logger.logInfo("Unable to obtain the OMSCB HTTP Destination " + OMSCB_DESTINATION_NAME + " : " + de);
--- end code snippet ---
When I first got the ClassCastException, I had assumed it was from the line where I get the destination and cast it to an HTTPDestination.  It turns out, though, that I was wrong, and the cast error actually happens in casting the DestinationService.
This class is in an EJB DC project, and I have checked my DC dependencies to make sure that I'm including the com.sap.exception, security.class, and tc/sec/destinations/interface DCs as Used DCs.  I have also verified that the corresponding EAR project has those three libraries included as references in the application-j2ee-engine.xml.  Before I had set those references, I was getting an error on deployment, but now the class deploys just fine.
I did notice (both through looking at the JNDI registry in Visual Administrator and by examining the class of the object returned by the JNDI lookup) that the object returned by the JNDI lookup is a proxy object for a P4 binding stub.  I guess that's an RMI-accessible object?  I was wondering if I was missing a reference to the class that contains the binding stub.
The JNDI values for the tcsecdestinations~service object are:
[Class Name]: $Proxy111
[Object Value]: RMI_P4:Dynamic Stub:com.sap.security.core.server.destinations.service.DestinationServiceImpl@3b6dbd
Anyway, I'm stumped.  Any help would be greatly appreciated.
Thanks,
- Bill

Answer 1

Hi Vinoth,
Thanks for the reply.  Unfortunately, I've already looked at it, and it did not solve my problem.  I had gotten the sample code from there, but it didn't help with the runtime ClassCastException.
However, I was able to resolve the problem.  It turns out that, in additon to the three library references in the application-j2ee-engine.xml, you need to add a reference to the tcsecdestinations~service service.  Once you add that and redeploy, the ClassCastException goes away.
I believe that the problem was caused by JNDI returning a proxy object to an unresolvable class.
Hope that helps someone else,
- Bill