Java Remote Desktop Administration

Question

I am Working on a Java Remote desktop Administration . It works fine when i run the Server initiator main class seperately. but when i am calling that class from an action event of a button the frame just freezes and shows a black screen ..here is the code. Any Help ?

import java.awt.BorderLayout;
import java.io.IOException;
import java.net.ServerSocket;
import java.net.Socket;
import javax.swing.JDesktopPane;
import javax.swing.JFrame;
import javax.swing.JOptionPane;


public class ServerInitiator {
    //Main server frame
    private JFrame frame = new JFrame();
    //JDesktopPane represents the main container that will contain all
    //connected clients' screens
    private JDesktopPane desktop = new JDesktopPane();

    public static void main(String args[]){
        String port = JOptionPane.showInputDialog("Please enter listening port");
       new ServerInitiator().initialize(Integer.parseInt(port));
    }

    public void initialize(int port){

        try {
            ServerSocket sc = new ServerSocket(port);
            //Show Server GUI
            drawGUI();
            //Listen to server port and accept clients connections
            while(true){
                Socket client = sc.accept();
                System.out.println("New client Connected to the server");
                //Per each client create a ClientHandler
                new ClientHandler(client,desktop);
            }
        } catch (IOException ex) {
            ex.printStackTrace();
        }
    }

    /*
     * Draws the main server GUI
     */
    public void drawGUI(){
            frame.add(desktop,BorderLayout.CENTER);
            frame.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
            //Show the frame in a maximized state
            frame.setExtendedState(frame.getExtendedState()|JFrame.MAXIMIZED_BOTH);
            frame.setVisible(true);
    }
}

Answer 1

Your while loop is likely running from within the context of the Event Dispatching Thread, blocking it from processing any new events (including repaint events)

public void initialize(int port){

    try {
        ServerSocket sc = new ServerSocket(port);
        //Show Server GUI
        drawGUI();
        //Listen to server port and accept clients connections
        while(true){
            Socket client = sc.accept();
            System.out.println("New client Connected to the server");
            //Per each client create a ClientHandler
            new ClientHandler(client,desktop);
        }
    } catch (IOException ex) {
        ex.printStackTrace();
    }
}

See Concurrency in Swing for more details.

Instead, you should launch your server in a different Thread or use a SwingWorker if you want to be able to update the UI (simply and safely). See Worker Threads and SwingWorker for more details