<![CDATA[import java.awt.Toolkit;
import java.awt.event.*;
import com.sun.java.swing.*;
public class ProgressBarDemo extends JFrame {
public final static int ONE_SECOND = 1000;
JProgressBar progressBar;
Timer timer;
JButton startButton;
LongTask task;
public ProgressBarDemo() {
super("ProgressBarDemo");
task = new LongTask();
//create the demo's UI
startButton = new JButton("Start");
startButton.setActionCommand("start");
startButton.addActionListener(new ButtonListener());
progressBar = new JProgressBar();
progressBar.setMinimum(0);
progressBar.setMaximum(task.getLengthOfTask());
progressBar.setValue(0);
JPanel contentPane = new JPanel();
contentPane.add(startButton);
contentPane.add(progressBar);
contentPane.setBorder(BorderFactory.createEmptyBorder(20, 20, 20, 20));
setContentPane(contentPane);
//create a timer and a task
timer = new Timer(ONE_SECOND, new TimerListener());
}
//the actionPerformed method in this class
//is called each time the Timer "goes off"
class TimerListener implements ActionListener {
public void actionPerformed(ActionEvent evt) {
progressBar.setValue(task.getCurrent());
if (task.done()) {
Toolkit.getDefaultToolkit().beep();
timer.stop();
startButton.setEnabled(true);
}
}
}
//the actionPerformed method in this class
//when the user presses the start button
class ButtonListener implements ActionListener {
public void actionPerformed(ActionEvent evt) {
startButton.setEnabled(false);
progressBar.setValue(progressBar.getMinimum());
task.go();
timer.start();
}
}
public static void main(String[] args) {
JFrame frame = new ProgressBarDemo();
WindowListener l = new WindowAdapter() {
public void windowClosing(WindowEvent e) {
System.exit(0);
}
};
frame.addWindowListener(l);
frame.pack();
frame.setVisible(true);
}
}
]]>