java给按钮加监视器 java实现按钮

Java codepackage de;
import java.awt.*;
import java.awt.event.ActionEvent;
import java.awt.event.ActionListener;
import javax.swing.*;
public class som extends JFrame implements ActionListener{
private static final long serialVersionUID = 1L;
static int i=0;
JButton jb;
boolean mark;
public som()
{
Panel p = new Panel();
jb = new JButton("关");
jb.addActionListener(this);
p.add(jb);
add(p);
this.setVisible(true);
this.pack();
}
public static void main(String args[])
{
new som();
}
@Override
public void actionPerformed(ActionEvent e) {
// TODO Auto-generated method stub
if(e.getSource()==jb)
{
if(i%2==0)
{
jb.setActionCommand("开");
[color=#FF0000]jb.setText(" 关");//这里忘了改变文本值，所以你看不出效果来[/color]
mark=true; //用于中止线程的run()方法
i=i+1;
}
else
{
mark = false;
jb.setActionCommand("关");
[color=#FF0000]jb.setText(" 关");//这里忘了改变文本值，所以你看不出效果来[/color]
i=i+1;
}
}
}
}