java用线程显示时间 java线程实现倒计时

package 倒计时;

import java.util.Scanner;
class  MyThread implements Runnable{
    Scanner s=new Scanner(System.in);
    //gprivate int time=6;
    @Override
    public void run() {
        int time=6;
        // TODO Auto-generated method stub
        System.out.println("倒计时"+(time-1)+"秒");//打印倒计时5秒
        try {
            
            for (int i = 1; i <= 5; i++) {//遍历输出
                Thread.sleep(1000, 100);
                time--;//实现从5，4,3,2,1,
                if(time!=0){//不输出0这个时间
                System.out.println(time);
            }
        }
            System.out.println("开始");
            System.out.println("请选择：");
            System.out.println("1.重新刷新");
            System.out.println("2.查看");
            System.out.println("3.推出");
            int key=s.nextInt();
            switch (key) {
            case 1:
                System.out.println("重新刷新");
                run();
                break;
            case 2:
                System.out.println("查看");
                break;
            case 3:
                System.out.println("推出");
                System.exit(0);
            default:
                System.out.println("输入有误，推出系统");
                System.exit(0);
                break;
            }        
        } catch (InterruptedException e) {
            // TODO Auto-generated catch block
            e.printStackTrace();
            System.out.println("系统出现异常");
        }
        System.out.println();
    }
}
public class countdown {
    public static void main(String[] args) {
        MyThread my=new MyThread();//初始化对象
        Thread t=new Thread(my,"线程");
        t.start();//线程开始
    }
}