How to make the server respond with a popup?

Question

I want to make the server respond with a popup?my code is like this,but it does not work,why?
<code>
public class Welcome2
     public static void main(String[] args)throws IOException
          ServerSocket server = new ServerSocket(2222);
          while(true)
               Socket s = server.accept();
               BufferedReader in = new BufferedReader(new InputStreamReader(s.getInputStream()));
               String msg = in.readLine();
               if(msg.equals("visitor"))
                    System.out.println("recv...");               
                    JOptionPane.showMessageDialog(null,"Visitor coming!\n");
     System.exit(0);
               server.close();
</code>
it can properly print out "recv...",but no popup,why?

Answer 1

Define "does not work". What happens?
Does your program compile? Do you get an exception? Does the program receive a line? Is the line equal to whatever you expect? Is showMessageDialog() called? Put in some debugging println's to see what happens.