实现倒计时

public static void main(String[] args) throws InterruptedException {
        CountDown(10);
        Count(10);
}
public static void  CountDown(int t) throws InterruptedException {
    System.out.println("倒计时："+t);
    while(t>0){
        Thread.sleep(1000);//线程sleep():休眠，会自动启动，单位：毫秒
        t--;
        System.out.println("时间是："+t);
     }
    System.out.println("时间结束");
}
public static void  Count(int limitSec) throws InterruptedException {
    System.out.println("Count from "+limitSec);
    while(limitSec > 0){
        --limitSec;
        System.out.println("remians "+ limitSec +" s");
        TimeUnit.SECONDS.sleep(1);//休眠1秒
    }
    System.out.println("Time is out");
}

(1) sleep();休眠,会自动启动