Classcastexception with rmi-iiop

Question

Hi,
I try the rmi-iiop example in examples/rmi_iiop/hello using Sun's JDK 1.3rc1 on Linux. I use weblogic.rmic to generate an IDL file from HelloImpl.class. Next, I use idlj (comes with the JDK) to generate those help .java files from IDL. Then, I compile these files and HelloClient.java. I start Weblogic(SP6) and launch HelloClient using the command,
java examples.rmi_iiop.hello.HelloClient {long IOR number string}
Weblogic server throws this exception when the client make a contact,
Sun Dec 17 16:52:33 GMT+08:00 2000:<I> <WebLogicServer> WebLogic Server started
Sun Dec 17 16:52:40 GMT+08:00 2000:<I> <ListenThread> Adding address: localhost/127.0.0.1 to licensed client list
Sun Dec 17 16:52:40 GMT+08:00 2000:<E> <Adapter> Exception thrown by rmi server: [-8596339638698095515S127.0.0.1:[7001,7001,7002,7002,7001,-1]/8]
java.lang.ClassCastException: examples.rmi_iiop.hello.HelloImpl
     at weblogic.cos.naming.NamingContextImpl.resolve(NamingContextImpl.java:138)
     at weblogic.cos.naming.NamingContext_WLSkel.invoke(NamingContext_WLSkel.java:53)
     at weblogic.rmi.extensions.BasicServerObjectAdapter.invoke(BasicServerObjectAdapter.java:347)
     at weblogic.rmi.extensions.BasicRequestHandler.handleRequest(BasicRequestHandler.java:69)
     at weblogic.rmi.internal.BasicExecuteRequest.execute(BasicExecuteRequest.java:15)
     at weblogic.kernel.ExecuteThread.run(ExecuteThread.java:135)
Why there is a ClassCastException? If there a compatiblity problem with idlj that comes with the JDK? Please advise.

Answer 1

Generally, this is a classpath problem. You must ensure that the classes that are produced by jidl are not in the WLS classpath; similarly, the RMI interfaces must not be visible to the java CORBA client.
IMO, a java CORBA client is not a viable development platform.
TH Lim wrote:
Hi,
I try the rmi-iiop example in examples/rmi_iiop/hello using Sun's JDK 1.3rc1 on Linux. I use weblogic.rmic to generate an IDL file from HelloImpl.class. Next, I use idlj (comes with the JDK) to generate those help .java files from IDL. Then, I compile these files and HelloClient.java. I start Weblogic(SP6) and launch HelloClient using the command,
java examples.rmi_iiop.hello.HelloClient {long IOR number string}
Weblogic server throws this exception when the client make a contact,
Sun Dec 17 16:52:33 GMT+08:00 2000:<I> <WebLogicServer> WebLogic Server started
Sun Dec 17 16:52:40 GMT+08:00 2000:<I> <ListenThread> Adding address: localhost/127.0.0.1 to licensed client list
Sun Dec 17 16:52:40 GMT+08:00 2000:<E> <Adapter> Exception thrown by rmi server: [-8596339638698095515S127.0.0.1:[7001,7001,7002,7002,7001,-1]/8]
java.lang.ClassCastException: examples.rmi_iiop.hello.HelloImpl
at weblogic.cos.naming.NamingContextImpl.resolve(NamingContextImpl.java:138)
at weblogic.cos.naming.NamingContext_WLSkel.invoke(NamingContext_WLSkel.java:53)
at weblogic.rmi.extensions.BasicServerObjectAdapter.invoke(BasicServerObjectAdapter.java:347)
at weblogic.rmi.extensions.BasicRequestHandler.handleRequest(BasicRequestHandler.java:69)
at weblogic.rmi.internal.BasicExecuteRequest.execute(BasicExecuteRequest.java:15)
at weblogic.kernel.ExecuteThread.run(ExecuteThread.java:135)
Why there is a ClassCastException? If there a compatiblity problem with idlj that comes with the JDK? Please advise.