i have made a socketed application, but i have a problem now...
when someone connects, they connect without problems, but when they log out, often they log out and just leave the connection on the server, which will create a null... i want to terminate the connection when they log out.

my socket

Code:
    public void run() {
        // setup the listener
        try {
            shutdownClientHandler = false;
            clientListener = new java.net.ServerSocket(serverlistenerPort, 1,
                    null);

            while (true) {
                java.net.Socket s = acceptSocketSafe(clientListener);

                s.setTcpNoDelay(true);
                String connectingHost = s.getInetAddress().getHostName();

                if (/* connectingHost.startsWith("localhost") || connectingHost.equals("127.0.0.1")*/true) {
                    if (connectingHost.startsWith("computing")
                            || connectingHost.startsWith("server2")) {
                        misc.println(
                                connectingHost
                                        + ": Checking if server still is online...");
                    } else {
                        int Found = -1;

                        for (int i = 0; i < MaxConnections; i++) {
                            if (Connections[i] == connectingHost) {
                                Found = ConnectionCount[i];
                                break;
                            }
                        }
                        if (Found < 3) {
                            misc.println(
                                    "Connection accepted from " + connectingHost
                                    + ": " + s.getPort() + ".");
                            playerHandler.newPlayerClient(s, connectingHost);                  
                        } else {
                            s.close();
							s = null;
                        }
                    }
                } else {
                    misc.println(
                            "ClientHandler: Rejected " + connectingHost + ":"
                            + s.getPort());
                    s.close();
					s = null;
                }
            }
        } catch (java.io.IOException ioe) {
            if (!shutdownClientHandler) {
                misc.println("Error: KILL " + serverlistenerPort);
            } else {
                misc.println("ClientHandler was shut down.");
            }
        }
    }