J2SE怎么实现在事务方面操作的时候有时会等待很久,做一个进度条来展现事务完成状态

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.
try {