Timer作为java开发中常用的一个定时工具，配合JProgressBar使用起来还真是方便，只需要调用timer.start()方法就能激活并运行，然后调用stop()方法便能停止，还可以再次通过restart()方法重新使其运行，下面就直接上代码吧：

package UsefulKnowledge;import java.awt.BorderLayout;
import java.awt.Container;
import java.awt.Dimension;
import java.awt.Image;
import java.awt.MenuItem;
import java.awt.PopupMenu;
import java.awt.SystemTray;
import java.awt.Toolkit;
import java.awt.TrayIcon;
import java.awt.event.ActionEvent;
import java.awt.event.ActionListener;
import java.awt.event.WindowAdapter;
import java.awt.event.WindowEvent;import javax.swing.JButton;
import javax.swing.JFrame;
import javax.swing.JLabel;
import javax.swing.JPanel;
import javax.swing.JProgressBar;
import javax.swing.Timer;
import javax.swing.event.ChangeEvent;
import javax.swing.event.ChangeListener;public class TimerAndProgressBar implements ActionListener,ChangeListener{JFrame f=null;JProgressBar progressBar=null;JLabel label;Timer timer;JButton b;public TimerAndProgressBar() {// TODO Auto-generated constructor stubf=new JFrame("ProgressBar and Timer Test");Container containerPane=f.getContentPane();label=new JLabel("",JLabel.CENTER);progressBar=new JProgressBar();progressBar.setOrientation(JProgressBar.HORIZONTAL);progressBar.setMinimum(0);progressBar.setMaximum(100);progressBar.setValue(0);progressBar.setStringPainted(true);progressBar.addChangeListener(this);progressBar.setPreferredSize(new Dimension(200,30));JPanel panel=new JPanel();b=new JButton("Start");b.addActionListener(this);panel.add(b);timer=new Timer(50,this);containerPane.add(panel,BorderLayout.NORTH);containerPane.add(progressBar,BorderLayout.CENTER);containerPane.add(label,BorderLayout.SOUTH);f.pack();f.setVisible(true);f.addWindowListener(new WindowAdapter(){@Overridepublic void windowClosing(WindowEvent e) {// TODO Auto-generated method stubSystem.exit(0);}});}public static void main(String []args){new TimerAndProgressBar();}@Overridepublic void stateChanged(ChangeEvent e) {// TODO Auto-generated method stubint value=progressBar.getValue();if(e.getSource()==progressBar){label.setText("目前已完成进度："+Integer.toString(value)+"%");}}@Overridepublic void actionPerformed(ActionEvent e) {// TODO Auto-generated method stubif(e.getSource()==b){timer.start();}if(e.getSource()==timer){int value=progressBar.getValue();if(value<100){value++;progressBar.setValue(value);}else{timer.stop();progressBar.setValue(0);}}}}

我们在程序中设置了stateChanged方法来侦听进度条的value的改变，从而达到对其的控制。是不是感觉很方便。