Java第六次作业

import java.awt.;
import java.awt.event.;
import javax.swing.*;

class GoodLucky extends JFrame implements ActionListener
{

JTextField tf = new JTextField();
JButton b1 = new JButton("开始");
JButton b2 = new JButton("停止");
JLabel ll=new JLabel("本期中奖号码为：102034");

boolean sg=false;
public GoodLucky(){
b1.setActionCommand("start");
JPanel p = new JPanel();
p.add(b1);
p.add(b2);

b1.addActionListener(this);
b2.addActionListener(this);
b2.setEnabled(false);

this.getContentPane().add(tf,"North");
this.getContentPane().add(ll);
this.getContentPane().add(p,"South");
this.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
this.setSize(300,200);
this.setLocation(300,300);
Cursor cu = new Cursor(Cursor.HAND_CURSOR);
this.setCursor(cu);
this.setVisible(true);
tf.setText("祝大家鸿运！");
this.go();

}

public void go()
{
while(true)
{
if(sg==true)
{
String s = " ";
for(int j = 1; j <= 5;j++)
{
int i = (int)(Math.random() * 9) + 1;
if(i < 10)
{
s = s + " 0" + i;
}
else
{
s = s + " " + i;
}

        } 
        tf.setText(s); 
   } 

   try 
   { 
    Thread.sleep(100); 
   } 
   catch(java.lang.InterruptedException e) 
   { 
    e.printStackTrace(); 
   } 

} 

}

public void actionPerformed(ActionEvent e)
{
String s = e.getActionCommand();
if(s.equals("start"))
{
sg = true;
b1.setEnabled(false);
b2.setEnabled(true);
}
else
{
sg= false;
b2.setEnabled(false);
b1.setEnabled(true);
}
}

public static void main(String[] args)
{
new GoodLucky();
}
}