How can I make my program Run forever?

Question

I would like to know how can I make my program execute some method while the GUI still open. I have something like this.
  public static void main(String args[]) {
    System.out.println("****************************");
    System.out.println("    PACKET READER CONSOLE   ");
    System.out.println("****************************");
    IPDetector window = new IPDetector(); // IPDetector is the JFrame
    window.setTitle("IPDetector Analyzer");
    window.pack();
    window.show();
    PortListener pl = new PortListener();// Is my portlistener class
    PacketReader c = new PacketReader();
    while(JFrame still open){// I dont know how to put a statemente here
      pl.start();// this method reads from a port and returns a string
      String cc = pl.data;// gets the string from the port listener
      while(!cc.equals("")){
        c.portWriter(cc);// writes the string into a file
  }I want that my portlistener keeps reading all the time, and if is something in the socket information.
Should I use a thread? Any ideas? thanks.
Chris

Answer 1

I still not understanding how to make it thread. My main class is this one IPDetector. and it looks like this.
public class IPDetector extends JFrame {
  // Declaration of the instance variables
  private static ArrayofDisplay  ad = new ArrayofDisplay();
  private ArrayofCreators database = new ArrayofCreators();
  JLabel sourceLabel;//etc..
  public IPDetector() {
    IPDetectorLayout customLayout = new IPDetectorLayout();
    getContentPane().setFont(new Font("Helvetica", Font.PLAIN, 12));
    getContentPane().setLayout(customLayout);
    sourceLabel = new JLabel("Source IP Add.");
    getContentPane().add(sourceLabel); 
    addWindowListener(new WindowAdapter() {
      public void windowClosing(WindowEvent e) {
        System.exit(0);
  // I get confused here...
  private boolean alive; // Do I need to declared here?
  public void setAlive(boolean val) { // This one also?
    alive = val;
  // IPDetector Methods...
  public void displayCaller(ArrayofDisplay aD){  }
  public void setAndReplace(String text)  {    }
  public void refresh(){ }
  public boolean action(Event evt, Object arg){ }
  //etc...
  public static void main(String args[]) {
    System.out.println("***********************************************");
    IPDetector window = new IPDetector();
    window.setTitle("IPDetector");
    window.pack();
    window.show();
    PortListener pl = new PortListener();
    PacketReader c = new PacketReader();
    while (alive) {// Is this correct here?
      pl.start();
      String cc = pl.data;
      while(!cc.equals("")){
        c.portWriter(cc);
        window.refresh();
        cc = "";
class IPDetectorLayout implements LayoutManager {
  public IPDetectorLayout() {  }
  public void addLayoutComponent(String name, Component comp) {  }
  public void layoutContainer(Container parent) {  }
}