线程休眠

package cn.ruhsang.state;

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

//模拟倒计时,获取当前系统时间
public class TestSleep2 {
    public static void main(String[] args)  {
        // tenDown();
         //打印当前系统时间
        Date startTime = new Date(System.currentTimeMillis());//获取当前的系统时间
        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;
            }
        }
    }
}