Stumped with SwingWorker -- code compiles but doesn't run right

Question

Okay, sorry to post a ton of code, but I'm creating a swing gui that will use swing worker to create an object of the followng class, one method that sleeps and returns a random number:
public class BigJob{
     public int doBigJob(){
          try {
          Thread.sleep(15000);
          } catch (InterruptedException e){
          e.printStackTrace();
     int number = (int)(Math.random() * 50);
     return number;
}I can get the gui program below to run without the SwingWorker, but am having trouble getting it to run properly. The code posted below compiles and starts up ok, but when I click the "click to do big job" button, it just doesn't do anything.
I created a runnable in the main method, and invoked the method to build the gui, so that's working.
I have the SwingWorker defined in an inner class that implements ActionListener; I'm guessing that's the problem. I should probably put the SwingWorkder in its own inner class, and invoke it from the first listener class?
here's the code:
import javax.swing.*;
import java.awt.event.ActionListener;
import java.awt.event.ActionEvent;
import java.awt.BorderLayout;
import javax.swing.SwingWorker;
public class WorkerTest{
     private JFrame frame;
     private JButton button1;
     private JButton button2;
     private JButton button3;
     private JPanel topPanel;
     public static void main (String[] args){
     SwingUtilities.invokeLater(new Runnable() {
          public void run(){
          WorkerTest wtest = new WorkerTest();
          wtest.buildGui();
     } // end main
     public void buildGui(){
     frame = new JFrame("frame to test swing worker");
     frame.setSize(700,200);
     frame.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
     frame.setLayout(new BorderLayout());
     topPanel = new JPanel();
     frame.add(topPanel, BorderLayout.NORTH);
     button1 = new JButton("click to change text");
     button1.addActionListener(new Button1Listener());
     button2 = new JButton("click to do big thing");
     button1.addActionListener(new Button2Listener());
     button3 = new JButton("click to change text");
     button3.addActionListener(new Button3Listener());
     topPanel.add(button1);
     topPanel.add(button2);
     topPanel.add(button3);
     frame.setVisible(true);
// inner classes to add listeners
     class Button1Listener implements ActionListener{
          public void actionPerformed(ActionEvent e){
          button1.setText("i've been clicked");
     class Button2Listener implements ActionListener{
          public void actionPerformed(ActionEvent e){
          // execute job in main thread
          //BigJob job = new BigJob();
          //button2.setText("big job is done: " + job.doBigJob());
          // execute job in its own thread:
          SwingWorker worker = new SwingWorker<BigJob, Void>(){
          BigJob job;
          int resultNum;
               public BigJob doInBackground(){
               job = new BigJob();
               resultNum = job.doBigJob();
               button2.setText("big job done: " + resultNum);
               return job;
     class Button3Listener implements ActionListener{
          public void actionPerformed(ActionEvent e){
          button3.setText("i've been clicked also");
} // end WorkerTestthanks,
bp

Answer 1

badperson wrote:
where in the code should that go, in the listener class?
SwingWorker worker = new SwingWorker<BigJob, Void>() {
    public BigJob doInBackground() {
        // code
     return job;
worker.execute();