IllegalArgumentException: object is not an instance of declaring class

Question

Hi all,
I know that this is the not exact forum to post this issue.
I'm working on a clustered environment and my server details are given below
a) jboss-4.0.2
b) J2SDK-1.4.2_09
In my jboss.xml file, I have defined
       <session>
            <ejb-name>ExampleSLBean</ejb-name>
            <jndi-name>ExampleSLHome</jndi-name>
            <cache-invalidation>true</cache-invalidation>
            <clustered>true</clustered>
       </session>And in my servlet i have written below code to lookup up a Stateless Session bean
Hashtable hashtable = new Hashtable();
hashtable.put(Context.INITIAL_CONTEXT_FACTORY,"org.jnp.interfaces.NamingContextFactory");
hashtable.put(Context.URL_PKG_PREFIXES, "jboss.naming:org.jnp.interfaces");
hashtable.put(Context.PROVIDER_URL, "localhost:1100");
Context context = new InitialContext(hashtable);            
Object objectRef = context.lookup("ExampleSLHome");
System.out.println("objectRef ::: "+objectRef)
ExampleSLHome home = (ExampleSLHome) PortableRemoteObject.narrow(objectRef, ExampleSLHome.class);after the context.lookup("ExampleSLHome") statement, I'm getting the error as
java.lang.IllegalArgumentException: object is not an instance of declaring class.
I'm not able to find the possible cause of the problem.
Please help me
thanks
arvind

Answer 1

Try this:
Class objCls = Class.forName ("ClassName");
Object obj = objCls.newInstance();
method.invoke(objCls , null);
This will throw an exception. However, following will work:
method.invoke(obj , null);
OR
method.invoke(new ClassName(), null);
Refer to the following thread for detailed discussion:
http://forum.java.sun.com/thread.jspa?threadID=439811&messageID=1980996