[equinox-dev] OSGi & RMI

["Patrick Bakker" <patrick@xxxxxxxxxxxx>]

Hi,
I'm experimenting with the best way to modularize an application using Swing to communicate to stateless session beans. I'm using Java SE 5 + JBoss 4.2.0.CR2 + Eclipse 3.2.2.
I know its some kind of classloader/isolation issue with OSGi/RMI because I can construct a simple Java application that works fine.

Suppose I have 5 bundles (I'm using Eclipse bundles rather than OSGi but I'm using Swing not SWT) & their important classes:
example.app
example.registrar.bean
  BeanRegistrar (singleton)
  
jndi.properties
example.client
example.clientserver
  IExample
  IExampleRemote
example.server
  ExampleBean

For JBoss I use an ant script to create jar from the packages in example.clientserver and 
example.server to create example.server.jar which I drop in the deploy directory:

@Stateless
@RemoteBinding(IExampleRemote.DEFAULT_JNDI_NAME)
public class ExampleBean implements IExample, IExampleRemote
{
  public void doSomething()
  {
    System.out.println("hello");
  }
}

public interface IExample
{
  public void doSomething();
}

@Remote
public interface IExampleRemote extends IExample
{}

For the client I have everything packaged as individual bundles. When example.client needs a bean it starts another thread which calls BeanRegistrar.lookup(String jndiName) to get a reference to a remote bean.

public class Task extends Thread
{
  boolean inSwing;
  TaskCallback callback;

  public void Task(TaskCallback callback)
  {
    this.callback = callback;
    inSwing = false;
  }

  public void run()
  {
    if (inSwing)
    {
      callback.taskComplete();
    }
    else
    {
      IExampleRemote example = (IExampleRemote) BeanRegistrar.lookup(IExampleRemote.DEFAULT_JNDI_NAME
);
      example.doSomething();

      inSwing = true;
      SwingUtilities.invokeLater(this);
    }
  }
}

If I collapse this entire example down to a simple Java application instead of bundles it works fine.
If I run it as an Eclispe RCP, I get:

java.lang.ClassCastException: $Proxy0 cannot be cast to example.clientserver.IExampleRemote
    at example.client.Task.run(Task.java:xx) <-- stops at the line with BeanRegistrar.lookup

I've googled around extensively and OSGi/RMI issues come up in several places but the closest anybody gets to answering anything is to hint that this may be problematic and the conversation ends just before anybody says anything useful. A few other documents mention the Eclipse Buddy policy extension. I've experimented with it but have not had any success yet. Also, I'm not sure exactly what I'm trying to do so I'm basically just guessing at possible combinations.

I am running the program under the default Java security manager with the following permissive policy:
grant
{
    permission java.security.AllPermission;
};

I do that by supplying VM arguments to the run program option in Eclipse:
-Djava.security.manager
-Djava.security.policy="/Configuration/security.conf"
-Djava.security.auth.login.config="/Configuration/jaas.conf"

Can anybody help me get to the bottom of this?