RMI Server and clientID

[Miguel Roque]

Hello.
I'me making my server and I have some problems with it. I have it as follows:

  
interface DataInterface extends Remote
class Data implements DataInterface
public class ServerDatabaseImplementation extends UnicastRemoteObject implements DataInterface, Unreferenced 

The connection to the database in the client side is made using a connection factory as follows:

public DataInterface getDatabaseConnection(boolean localMode, String params[] ) throws 
        RemoteException, NotBoundException, IOException, DatabaseException {
    if (localMode) {
        if (params.length == 1) {
            return new LocalDatabaseImplementation(params[0]);
        } else {
            throw new DatabaseException("Wrong arguments passed! Could not open the Database.");
        }
    } else {
        if (params.length == 3) {
            if (params[0].startsWith("rmi://") == false) {
                params[0] = "rmi://"+params[0];
            }
            return (DataInterface)Naming.lookup(params[0]+":"+params[1]+"/"+SERVER_NAME);
        } else {
            throw new DatabaseException("Wrong arguments passed! Could not connect to server.");
        }
    }
}

And the RemoteServerImplementation is created as follows:

public ServerDatabaseImplementation(int portNr, String databaseLocation) throws
            RemoteException, 
            IOException,
            ClassNotFoundException{
        super(); 
        Naming.rebind(SERVER_NAME, this);
        database = new Data(databaseLocation);
        System.out.println("Server running and listening...");
        System.out.println("Waiting for connections...");
}
... All the public methods of Data class
public static void main(String args[]){
    // parameters check
    try {
            new ServerDatabaseImplementation(0, args[0]);
    } catch (RemoteException exp) {
        System.out.println("Remote exception: "+exp.toString());
    } catch (MalformedURLException exp) {
        System.out.println("Malformed URL Exception: "+exp.toString());
    } catch (IOException exp) {
        System.out.println("IO Exception: "+exp.toString());
    } catch (ClassNotFoundException exp) {
        System.out.println("Class Not Found Exception: "+exp.toString());
    } 
}

My question is, how can I get a unique clientID? I've tried some methods from RMI like getClientHost() and others, but if I open 2 clients i get the same values !
Thanks,
Miguel

[John Smith]

My question is, how can I get a unique clientID? I've tried some methods from RMI like getClientHost() and others, but if I open 2 clients i get the same values !

A common solution to this problem is to use a RMI Factory Pattern. Essentially, you bind a factory to the registry, the client gets the factory, invokes a method on that factory, and the factory creates another remote object which can be used to call the business methods. This remote object itself can then be used as a client identity. That is, all clients use the same object when they look up the registry, but each client gets a unique remote object to play with.
This "RMI factory" is such as clear and powerful pattern, that it is really hard to find a good alternative solution. That's why the most cowboys here take it as it is.
Eugene.
[ January 16, 2003: Message edited by: Eugene Kononov ]

[Deedy Dee]

How to manage the clientId in the server side, If apply the RMI Factory DP?

deedy