sleep的使用

package com.sean.base.threadStudy;

import com.sean.base.object01.SimpleDateFormatDemo;

import java.text.SimpleDateFormat;
import java.util.Date;

/**
 *
 * @create 2021-02-27 19:08
 */
public class SleepStudyDemo02 {
    public static void main(String[] args) {
      //打印当前系统时间
        Date startTime = new Date(System.currentTimeMillis());//获取系统当前时间
        while(true){
            try {Thread.sleep(1000);
                System.out.println(new SimpleDateFormat("HH:mm:ss").format(startTime));
                startTime=new Date(System.currentTimeMillis());//更新当前时间
            }catch (InterruptedException e){
                e.printStackTrace();
            }
        }
    }

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