JAVA实现动态页面加载进度条

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package components;

import java.awt.*;
import java.awt.event.*;
import javax.swing.*;
import java.beans.*;
import java.util.Random;

public class ProgressBarDemo extends JPanel
                             implements ActionListener, 
                                        PropertyChangeListener {

    private JProgressBar progressBar;
    private JButton startButton;
    private JTextArea taskOutput;
    private Task task;

    class Task extends SwingWorker<Void, Void> {
        /*
         * Main task. Executed in background thread.
         */
        @Override
        public Void doInBackground() {
            Random random = new Random();
            int progress = 0;
            //Initialize progress property.
            setProgress(0);
            while (progress < 100) {
                //Sleep for up to one second.