java 如何倒计时并展现

1、import javax.swing.*;public   class   Test  extends   JFrame { JButton button; JPanel panel; Test1DaoJiShi2() {

2、super("10秒计数器");button=new JButton(); panel=new JPanel(); add(panel); panel.add(button); 

3、setSize(300,200); setVisible(true); ButtonAction tt=new ButtonAction(); tt.run(); } 

4、class ButtonAction extends Thread { int i=10; public void run() //线程在此开始执行{ while(i!=0) { try { 

5、sleep(1000);button.setText( "还有 " +i+ "秒 "); i--; } catch(Exception   eee) {} }

6、if(i==0) { JOptionPane.showMessageDialog(null, " 时间到！");} }} public static void main(String   args[]) { JFrame frm = new Test();frm.dispose();System.exit(0);} }