sleep打印当前时间

public static void main(String[] args) throws InterruptedException {
        //sleep打印系统时间
        while(true){
            //打印当前时间
            Date date = new Date(System.currentTimeMillis());//获取系统当前时间
            Thread.sleep(1000);
            System.out.println(new SimpleDateFormat("HH:mm:ss").format(date));
            date = new Date(System.currentTimeMillis());
        }
    }

//模拟倒计时
public static void tenDown2() throws InterruptedException {
    int num=10;
    while (true){
        Thread.sleep(1000);
        System.out.println(num--);
        if (num<0){
            break;
        }
    }
}