Question

I’m currently learning Java by developing a tool for creating and filling out multiple-choice-forms client-side and saving aswell as evaluating them server-side. I used a code skeleton from a RMI Tutorial for the network-part and it was working fine until just now. Both the client and the server application are in the same package but run as seperate applications. For easier developing they’re both running on the same system right now, although this will change when things are done.

So let’s cut to the chase with some code and what exactly goes wrong:

Server.java

Server() throws RemoteException {
    super();
}

public static void main(String[] args) {
    try {
        LocateRegistry.createRegistry(Registry.REGISTRY_PORT);
    }
    catch (RemoteException ex) {
        System.out.println("SERVER: " + ex.getMessage());
    }

    try {
        Naming.rebind("Server", new Server()); <---
    }
    catch(MalformedURLException ex) {
        System.out.println("SERVER: " + ex.getMessage());
    }
    catch(RemoteException ex) {
        System.out.println("SERVER: " + ex.getMessage());
    }
}

[...] methods that are called by the client via ServerInterface

The <— marks where the Client-GUI is started.

Client.java

private static Gui_loadSets gui_loadSets = new Gui_loadSets();

public static void main(String[] args) {
    loadGuiLoadSets();
}

This is where the first GUI is turned visible; the one to choose a form to load from. This GUI is loaded by starting the server EVEN IF I COMMENT THIS OUT. So the Server doesn’t really load the Client-App, but instead somehow magically accesses it’s GUI and showing it for no reason.

I already tried “stepping into” the line before the GUI is loaded, but I end up in an infinite loop eventually, so I really have no idea what is going an.

This is my first question here, so please forgive me if I missed out anything obvious.
Thanks for your help in advance. If you need any more code I’d be happy to supply, but most of the remaining code is all about the multiple-choice-forms.

Answer 1

Naming.rebind() needs a URL, not just a service name. It should be

Naming.rebind("rmi://localhost/Server", new Server());

But I’m puzzled by your comment on this line. The --> doesn’t ‘mark where the Client-GUI is started’, it marks the line where the remote object is constructed, exported, and bound into the Registry. The client GUI is at the client.