RMI no such object in table, Server communication error

Question

My goal is to create a Distributed computing program that launches a server and client at the same time. I need it to be able to install on a couple of machines and have all the machines communicating with each other, i.e. Master node and 5 slave nodes all from one application.

My problem is that I cannot properly use unicastRef, I'm thinking that it is a problem with launching everything on the same port, is there a better way I am overlooking?

this is part of my code (the part that matters)

try {

        RMIServer obj = new RMIServer();
        obj.start(5225);

    } catch (Exception e) {
       e.printStackTrace();

    }


      try {
            System.out.println("We are slave's ");
            Registry rr = LocateRegistry.getRegistry("127.0.0.1", Store.PORT, new RClient());

            Call ss = (Call) rr.lookup("FILLER");

            System.out.println(ss.getHello());

        } catch (Exception e) {
            e.printStackTrace();
        }
}

this is my main class (above)

this is the server class (below)

public RMIServer() { }

    public void start(int port) throws Exception {

        try {

            Registry registry = LocateRegistry.createRegistry(port, new RClient(), new RServer());

            Call stuff = new Call();

            registry.bind("FILLER", stuff);

            System.out.println("Server ready");
        } catch (Exception e) {
            System.err.println("Server exception: " + e.toString());
            e.printStackTrace();
        }
    }

I don't know what I am missing or what I am overlooking but the output looks like this.

Listen on 5225 Listen on 8776 Server ready We are slave's Listen on 8776 java.rmi.NoSuchObjectException: no such object in table at sun.rmi.transport.StreamRemoteCall.exceptionReceivedFromServer(StreamRemoteCall.java:255) at sun.rmi.transport.StreamRemoteCall.executeCall(StreamRemoteCall.java:233) at sun.rmi.server.UnicastRef.invoke(UnicastRef.java:359) at sun.rmi.registry.RegistryImpl_Stub.lookup(Unknown Source) at Main.main(Main.java:62)

line 62 is this ::: Call ss = (Call) rr.lookup("FILLER");

Answer 1

Maybe it's because your reference to the stub in your server class is local to the try block and the reference is immediately garbage collected after. Try making stuff a class variable instead.

Answer 2

See http://stackoverflow.com/questions/645208