problem adding notification listener from remote client

[mjea]

Hi all,

I've got a NullPointerException while using the addNotificationListener API in RMIAdaptor with JBoss 3.2.6. I first tried the example code from the admin and development guide and this works well, so I suppose the RMI adaptor is correctly configured. The exception occurs while registering the listener, so I don't even receive a first Notification object.
Here is my code

public class DistantNotificationClient
 implements RMINotificationListener, Serializable {

 public DistantNotificationClient() {
 try{
 String url = "jnp://" + "etbs159" + ":1099";
 String ini = "org.jnp.interfaces.NamingContextFactory";
 String pkgs = "org.jboss.naming,org.jnp.interfaces";
 Hashtable env = new Hashtable();
 env.put("java.naming.provider.url", url);
 env.put("java.naming.factory.initial", ini);
 env.put("java.naming.factory.url.pkgs", pkgs);
 Context ic = new InitialContext(env);
 RMIAdaptor server = (RMIAdaptor) ic.lookup("jmx/rmi/RMIAdaptor");
 ObjectName emitterName = new ObjectName("osp.smf.test:service=BroadcasterTest");
 server.addNotificationListener(emitterName, this, null, new Long(System.currentTimeMillis()));
 }catch(Exception e){
 e.printStackTrace();
 }

 }

 public void handleNotification(Notification event, Object handback){
 String type = event.getType();
 String message = event.getMessage();
 System.out.println("type = "+type+" \t message = "+message);
 }
}

and here is the Exception

java.lang.NullPointerException

at org.jboss.jmx.connector.invoker.InvokerAdaptorService.invoke(InvokerAdaptorService.java:234)

at sun.reflect.NativeMethodAccessorImpl.invoke0(Native Method)

at sun.reflect.NativeMethodAccessorImpl.invoke(NativeMethodAccessorImpl.java:39)

at sun.reflect.DelegatingMethodAccessorImpl.invoke(DelegatingMethodAccessorImpl.java:25)

at java.lang.reflect.Method.invoke(Method.java:324)

at org.jboss.mx.server.ReflectedDispatcher.dispatch(ReflectedDispatcher.java:60)

at org.jboss.mx.server.Invocation.dispatch(Invocation.java:62)

at org.jboss.mx.server.Invocation.dispatch(Invocation.java:54)

at org.jboss.mx.server.Invocation.invoke(Invocation.java:82)

at org.jboss.mx.server.AbstractMBeanInvoker.invoke(AbstractMBeanInvoker.java:197)

at org.jboss.mx.server.MBeanServerImpl.invoke(MBeanServerImpl.java:473)

at org.jboss.invocation.jrmp.server.JRMPInvoker.invoke(JRMPInvoker.java:360)

at sun.reflect.GeneratedMethodAccessor119.invoke(Unknown Source)

at sun.reflect.DelegatingMethodAccessorImpl.invoke(DelegatingMethodAccessorImpl.java:25)

at java.lang.reflect.Method.invoke(Method.java:324)

at sun.rmi.server.UnicastServerRef.dispatch(UnicastServerRef.java:261)

at sun.rmi.transport.Transport$1.run(Transport.java:148)

at java.security.AccessController.doPrivileged(Native Method)

at sun.rmi.transport.Transport.serviceCall(Transport.java:144)

at sun.rmi.transport.tcp.TCPTransport.handleMessages(TCPTransport.java:460)

at sun.rmi.transport.tcp.TCPTransport$ConnectionHandler.run(TCPTransport.java:701)

at java.lang.Thread.run(Thread.java:534)

at sun.rmi.transport.StreamRemoteCall.exceptionReceivedFromServer(StreamRemoteCall.java:247)

at sun.rmi.transport.StreamRemoteCall.executeCall(StreamRemoteCall.java:223)

at sun.rmi.server.UnicastRef.invoke(UnicastRef.java:133)

at org.jboss.invocation.jrmp.server.JRMPInvoker_Stub.invoke(Unknown Source)

at org.jboss.invocation.jrmp.interfaces.JRMPInvokerProxy.invoke(JRMPInvokerProxy.java:135)

at org.jboss.invocation.InvokerInterceptor.invoke(InvokerInterceptor.java:96)

at org.jboss.jmx.connector.invoker.client.InvokerAdaptorClientInterceptor.invoke(InvokerAdaptorClientInterceptor.java:58)

at org.jboss.proxy.SecurityInterceptor.invoke(SecurityInterceptor.java:55)

at org.jboss.proxy.ClientMethodInterceptor.invoke(ClientMethodInterceptor.java:55)

at org.jboss.proxy.ClientContainer.invoke(ClientContainer.java:85)

at $Proxy0.addNotificationListener(Unknown Source)

at com.alcatel.osp.mbean.test.DistantNotificationClient.<init>(DistantNotificationClient.java:30)

at com.alcatel.osp.mbean.test.DistantNotificationClient.main(DistantNotificationClient.java:87)

Does anybody have an idea of what went wrong ?
I certainly missed something or did something wrong but I can't find the problem.

Thanks for your help !

Maxime

[starksm64]

Go over the example from the admin/devel guide that uses a remote notification listener. You cannot simply pass an implementation of RMINotificationListener to the server. This has to be an exported rmi service as well.

[mjea]

I didn't find any example of remote RMINotificationListener in adminDevel guide (nor in wiki's or faq's). However I tried to register the listener as a rmi service.
So I made my listener extend UnicastRemoteObject and I added this code:

 public TestMain() {
 try{
 /*if (System.getSecurityManager() == null) {
 System.setSecurityManager(new RMISecurityManager());
 }*/
 DistantNotificationClient dnc = new DistantNotificationClient();
 Naming.bind("//138.203.236.159:1098/DistantNotificationClient", dnc);
 String url = "jnp://" + "etbs159" + ":1099";
 String ini = "org.jnp.interfaces.NamingContextFactory";
 String pkgs = "org.jboss.naming,org.jnp.interfaces";
 Hashtable env = new Hashtable();
 env.put("java.naming.provider.url", url);
 env.put("java.naming.factory.initial", ini);
 env.put("java.naming.factory.url.pkgs", pkgs);
 Context ic = new InitialContext(env);
 RMIAdaptor server = (RMIAdaptor) ic.lookup("jmx/rmi/RMIAdaptor");
 ObjectName emitterName = new ObjectName("osp.smf.test:service=BroadcasterTest");
 server.addNotificationListener(emitterName, dnc, null, new Long(System.currentTimeMillis()));
 }catch(Exception e){
 e.printStackTrace();
 }

 }

Now I get the following exception:

java.rmi.NoSuchObjectException: no such object in table

at sun.rmi.transport.StreamRemoteCall.exceptionReceivedFromServer(StreamRemoteCall.java:247)

at sun.rmi.transport.StreamRemoteCall.executeCall(StreamRemoteCall.java:223)

at sun.rmi.server.UnicastRef.invoke(UnicastRef.java:350)

at sun.rmi.registry.RegistryImpl_Stub.bind(Unknown Source)

at java.rmi.Naming.bind(Naming.java:111)

at com.alcatel.osp.mbean.test.TestMain.<init>(TestMain.java:18)

at com.alcatel.osp.mbean.test.TestMain.main(TestMain.java:80)

I couldn't find info on this exception that matches my problem. I ran my application from the same machine as JBoss (running Solaris 9).

[dimitris]

You don't need to bind dnc to the Naming service, it won't be looked up.

[mjea]

Ok. How do I export the NitificationClient as a RMI service, then ? If I skip the 'bind' action, then I get The NullPointerException back.