Very Basic Question on Threads and Object Manipulation between classes

Question

I have a feeling this is on the virge of being a stupid question but hey, its the right forum.
Lets assume I have a class that extends Jframe : Jframe1
In that frame there is only one Jlabel : Jlabel1
I want to create a thread that will affect Jlabel1
The thread will run an endless loop that will.. for example change the color of the label to a random color and then the thread will sleep for a given time. There is no use in this program. Its only meant to help me understand
I have looked up info and examples on threads. Unfortunately none were useful. Most examples try to illustrate the use of threads with the example of an applet digital clock. But it does not help with my problem, not to mention I dont want to delve into applets at this time.
I know I have to make a class that extends thread. Does it have to be an inner class?
How do I get to affect the frame's Jlabel1 from it? It says it doesn't know anything about it.

Answer 1

import javax.swing.*;
import java.awt.*;
import java.util.*;
public class Jframe1 extends JFrame implements Runnable{
  Container con;
  JLabel Jlabel1;
  Random rand;
  Color c;
  public Jframe1(){
    setDefaultCloseOperation(EXIT_ON_CLOSE);
    con = getContentPane();
    rand = new Random();
    Jlabel1 = new JLabel("bspus", JLabel.CENTER);
    Jlabel1.setOpaque(true);
    con.add(Jlabel1, BorderLayout.NORTH);
    setSize(300, 300);
    setVisible(true);
  public void run(){
    while (true){
      try{
        Thread.sleep(1000);
      catch (InterruptedException e){
        break;
      int n = rand.nextInt(16777216);
      c = new Color(n);
      SwingUtilities.invokeLater(new Runnable(){
        public void run(){
          Jlabel1.setBackground(c);
  public static void main(String[] args){
    Jframe1 jf = new Jframe1();
    new Thread(jf).start(); // you don't need to create a new thread
  }                         // because this Main thread is just
                            // another thread.
                            // here, only for demonstration purpose,
}                           // we make a new separate thread.