EJB with Weblogic 5.1

[cris abanades]

When I call a EJB in a servlet, it doesn't work but if I do this in an application client that calls EJB, it works perfectly.
What is the problem?
The exception is:
java.lang.ClassCastException at com.sun.corba.se.internal.javax.rmi.PortableRemoteObject.narrow(PortableRemoteObject.java:296)
at javax.rmi.PortableRemoteObject.narrow(PortableRemoteObject.java:137)
at src.servlet.gesServlet.init(gesServlet.java:122)
at src.servlet.mainServlet.init(mainServlet.java:38)
at weblogic.servlet.internal.ServletStubImpl.createServlet(ServletStubImpl.java:390)
at weblogic.servlet.internal.ServletStubImpl.createInstances(ServletStubImpl.java:349)
at weblogic.servlet.internal.ServletStubImpl.prepareServlet(ServletStubImpl.java:338)
at weblogic.servlet.internal.ServletStubImpl.getServlet(ServletStubImpl.java:164)
at weblogic.servlet.internal.ServletStubImpl.invokeServlet(ServletStubImpl.java:99)
at weblogic.servlet.internal.ServletContextImpl.invokeServlet(ServletContextImpl.java:742)
at weblogic.servlet.internal.ServletContextImpl.invokeServlet(ServletContextImpl.java:686)
at weblogic.servlet.internal.ServletContextManager.invokeServlet(ServletContextManager.java:247)
at weblogic.socket.MuxableSocketHTTP.invokeServlet(MuxableSocketHTTP.java:361)
at weblogic.socket.MuxableSocketHTTP.execute(MuxableSocketHTTP.java:261)
at weblogic.kernel.ExecuteThread.run(ExecuteThread.java:120)

[Tim Holloway]

I had a LOT of fun with this one about a year back. There are several DIFFERENT CLASSPATHS within WLS5.1 - the first thing you need to do is make sure that the EJB is accessible through the right one. I believe there's a warning in the docs in particular about not putting stuff in the servlet classpath if it should be somewhere else. Or maybe it's in the comments in the model config file?
Anyway, what will happen is essentially, there are two copies of the class instantiated, which superficially are identical, but which Java considers unique. So what should be a perfectly legitimate portableObjectNarrow() will fail. I think if you pull the EJB from the servlet classpath, internal WebLogic magic will still find the EJB for the servlet, but your message will go away.