java 创建一个进度条

import java.awt.event.ActionEvent;import java.awt.event.ActionListener;import javax.swing.JFrame;import javax.swing.ProgressMonitor;import javax.swing.SwingUtilities;import javax.swing.Timer;import javax.swing.UIManager;public class MonitorToolbar extends JFrame implements ActionListener{static ProgressMonitor pbar = new ProgressMonitor(null, "监视进度", "进度..",0, 100);static int counter = 0;public MonitorToolbar(){setSize(250, 100);setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);Timer timer = new Timer(500,this);//this特指事件发生  void actionPerformedtimer.start();setVisible(true);}public static void main(String[] args){UIManager.put("ProgressMonitor.progressText", "这个进程?");UIManager.put("OptionPane.cancelButtonText", "Go Away");new MonitorToolbar();}public void actionPerformed(ActionEvent e){SwingUtilities.invokeLater(new Runnable(){public void run(){if(pbar.isCanceled()){pbar.close();System.exit(1);}pbar.setProgress(counter);pbar.setNote("事件：" + counter + "% 完成");counter += 2;}});}}