Calling a method from a different class?

Question

Ok..
I been trying for hours... but im stumped.
How can I get this to work?
(Note: I cut this code down from over 600+ lines of code.. I left in a REALLY raw framework that shows where the basic problem is.)
public class Client extends JPanel implements Runnable {
// variable declarations...
    Socket connection;
    BufferedReader fromServer;
    PrintWriter toServer;
    public Client(){
// GUI creation...
// Create the login JFrame
    Login login = new Login()
    public void connect(){
    try {
            //Attempt to connect to the server
            connection = new Socket(ip,port);
            fromServer = new BufferedReader(new InputStreamReader(connection.getInputStream()));
            toServer = new PrintWriter(connection.getOutputStream());
            //Launch a thread here to read incoming messages from the server
            //so I dont block on reading
            new Thread (this).start();
    } catch (Exception e) {
        e.printStackTrace();
    public void run(){
        // This keeps reading lines from the server
        String s;
        try {
            //Read messages sent from the server - add them to chat window
            while ((s=fromServer.readLine()) != null) {
            txtChat.append(s);
        } catch (Exception e) {}
    public static void main(String args[]){
        // some init frame stuff
        frame = new JFrame();
        frame.getContentPane().add(new Client(),BorderLayout.CENTER);
     frame.setVisible(true);
class Login extends JFrame {
    JPanel pane;
    public Login() {
     super("Login");
     pane = new JPanel();
     JButton cmdConnect = new JButton("Connect");
        pane.add(cmdConnect);
     setContentPane(pane);
     setSize(300,300);
     setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
     cmdConnect.addActionListener(new ActionListener(){
         public void actionPerformed(ActionEvent ae){
          // I want to connect to the server when this button is pressed.
          // How can I call the connect method in the Client class?
}

Answer 1

Your posted code shows Login as an inner class. So one way to solve your problem is.
1. Make an instance variable to hold the instance. For example, after "PrintWriter toServer;" add "private Client client;"
2. In the Client constructor, add a line "client = this;"
3. In the Login actionPerformed(), use "client.connect();"
Another way is to have Login keep a reference to the Client that created it.
1. Add an instance variable to Login "private Client client;"
2. Change the Login constructor "public Login(Client c) {"
3. Add a line in the constructor "client = c;"
4. In the actionPerformed() "client.connect();"