简单的java进度条

import java.awt.GridBagLayout; 
import java.awt.event.ActionEvent; 
import java.awt.event.ActionListener; 
import javax.swing.JButton; 
import javax.swing.JFrame; 
import javax.swing.JProgressBar; 

public class Test extends JFrame { 
JProgressBar bar = new JProgressBar(); 
JButton button = new JButton("GO"); 

Test() { 
add(bar); 
add(button); 
setLayout(new GridBagLayout()); 
setSize(500, 500); 
setVisible(true); 

button.addActionListener(new ActionListener() { 
public void actionPerformed(ActionEvent e) { 
new Thread(new Runnable() { 
public void run() { 
for (int i = 0; i < 101; i++) { 
bar.setValue(i); 
try { 
java.util.concurrent.TimeUnit.MILLISECONDS 
.sleep(100); 
} catch (Exception e) { 

}