import java.awt.*;import java.awt.event.*;import javax.swing.*; public class ProgressMonitorDemo extends JFrame {    public final static int ONE_SECOND = 1000;    private ProgressMonitor progressMonitor;    private Timer timer;    private JButton startButton;    private LongTask task;    private JTextArea taskOutput;    private String newline = "\n";    public ProgressMonitorDemo() {        super("ProgressMonitorDemo");        task = new LongTask();        //Create the demo's UI.        startButton = new JButton("Start");        startButton.setActionCommand("start");        startButton.addActionListener(new ButtonListener());        taskOutput = new JTextArea(5, 20);        taskOutput.setMargin(new Insets(5,5,5,5));        taskOutput.setEditable(false);        JPanel contentPane = new JPanel();        contentPane.setLayout(new BorderLayout());        contentPane.add(startButton, BorderLayout.NORTH);        contentPane.add(new JScrollPane(taskOutput), BorderLayout.CENTER);        contentPane.setBorder(BorderFactory.createEmptyBorder(20, 20, 20, 20));        setContentPane(contentPane);        //Create a timer.        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) {            if (progressMonitor.isCanceled() || task.done()) {                progressMonitor.close();                task.stop();                Toolkit.getDefaultToolkit().beep();                timer.stop();                if (task.done()) {                    taskOutput.append("Task completed." + newline);                }                startButton.setEnabled(true);            } else {                progressMonitor.setNote(task.getMessage());                progressMonitor.setProgress(task.getCurrent());                taskOutput.append(task.getMessage() + newline);                taskOutput.setCaretPosition(                    taskOutput.getDocument().getLength());            }        }    }    /**     * The actionPerformed method in this class     * is called when the user presses the start button.     */    class ButtonListener implements ActionListener {        public void actionPerformed(ActionEvent evt) {            progressMonitor = new ProgressMonitor(ProgressMonitorDemo.this,                                      "Running a Long Task",                                      "", 0, task.getLengthOfTask());            progressMonitor.setProgress(0);            progressMonitor.setMillisToDecideToPopup(2 * ONE_SECOND);            startButton.setEnabled(false);            task.go();            timer.start();        }    }        public static void main(String[] args) {        JFrame frame = new ProgressMonitorDemo();        frame.addWindowListener(new WindowAdapter() {            public void windowClosing(WindowEvent e) {                System.exit(0);            }        });        frame.pack();        frame.setVisible(true);    }}