Swing/Threads, changing the GUI

Question

Hey all, I have a question related to the java swing class, and manipulating a GUI which is something that I have never done before. Basically I have a threaded Listener class which returns a status boolean. Related to that status, I have a Jlabel which is supposed to display green if the status is true, and red if the status is false, however it is not working correctly. Below is my code, and I would appreciate some help if anyone has a fix, or better way to do this... Thanks in advance
//Listener Class
public class Listener extends Thread{
     private boolean isGood = false;
     public Listener(//...) {
     public void run()
          // does stuff here that sets the isGood var
     public bool getIsGood()
          return this.isGood;
//GUI
public class Visualizer {
     private static Listener listener;
     public Visualizer(Listener listener){
          this.listener = listener;
          javax.swing.SwingUtilities.invokeLater(new Runnable() {
public void run() {
createAndShowGUI();
     private static JFrame frame;
     private static JLabel status;
     public static void createAndShowGUI() {
//Create and set up the window.
frame = new JFrame("Window");
frame.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
status = new JLabel("Listener... ");
status.setOpaque(true);
status.setBackground(Color.RED);
//Display the window.
frame.pack();
frame.setVisible(true);
frame.setSize(new Dimension(204, 115));
frame.setContentPane(status);
listener.start();
while(true){
     boolean isGood = listener.getIsGood();
if(isGood){
status.setBackground(Color.GREEN);
else{
status.setBackground(Color.RED);
     try{
          Thread.sleep(1000);
     }catch(Exception E){
          E.printStackTrace();
I purposely left out some of the code because I wanted to make it simpler to follow. Essentially this is what is going on, and hopefully someone can point out why its not working and how to fix it. Thank you for reading this.

Answer 1

thanks for the advice Petes, I was looking for the code tag before but didnt see it. I have created an SSCCE, and I apologize for not making it earlier. Here is the code. The threads seem to be getting stuck, and the label doesnt alternate between red and green as it should. Let me know if you need anything else:
package simplified;
public class Main{
     public static void main(String[] args) {
          Listener theListener = new Listener();
          theListener.start();
          Visualizer theView = new Visualizer(theListener);
//Listener Class
public class Listener extends Thread{
     private boolean isGood = false;
     public Listener() {
     public void run(){
          if(this.isGood == true){
               this.isGood = false;
          else{
               this.isGood = true;
          try{
               this.sleep(1000);
          }catch(Exception e){
               e.printStackTrace();
     public boolean getIsGood(){
          return this.isGood;
import java.awt.*;
import javax.swing.*;
import java.awt.Dimension;
public class Visualizer {
     private static Listener listener;
     public Visualizer(Listener listener){
     this.listener = listener;
     javax.swing.SwingUtilities.invokeLater(new Runnable() {
          public void run() {
               createAndShowGUI();
     private static JFrame frame;
     private static JLabel status;
     public static void createAndShowGUI() {
          //Create and set up the window.
          frame = new JFrame("Window");
          frame.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
          status = new JLabel("Listener... ");
          status.setOpaque(true);
          status.setBackground(Color.RED);
          //Display the window.
          frame.pack();
          frame.setVisible(true);
          frame.setSize(new Dimension(204, 115));
          frame.setContentPane(status);
          while(true){
               boolean isGood = listener.getIsGood();
               if(isGood){
                    status.setBackground(Color.GREEN);
               else{
                    status.setBackground(Color.RED);
               try{
                    Thread.sleep(1000);
               }catch(Exception E){
                    E.printStackTrace();
}