线程休眠

• sleep (时间)指定当前线程阻塞的毫秒数;
• sleep存在异常InterruptedException;
• sleep时间达到后线程进入就绪状态;
• sleep可以模拟网络延时，倒计时等。
• 每一个对象都有一个锁，sleep不会释放锁;

package com.wang.multiThread.state;

import com.wang.multiThread.demo01.TestThread4;

//模拟网络延时:放大问题的发生性。
public class TestSleep implements Runnable{
    //票数
    private int ticketNums = 10;

    @Override
    public void run() {
        while (true) {
            if (ticketNums <= 0) {
                break;
            }

            //模拟延时
            try {
                Thread.sleep(200);
            } catch (InterruptedException e) {
                e.printStackTrace();
            }

            System.out.println(Thread.currentThread().getName() + "拿到了第" + ticketNums-- + "票");
        }
    }

    public static void main(String[] args) {
        TestSleep ticket = new TestSleep();

        new Thread(ticket, "小明").start();
        new Thread(ticket, "老师").start();
        new Thread(ticket, "黄牛党").start();
    }
}

package com.wang.multiThread.state;

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

//模拟倒计时...
public class TestSleep2 {
    public static void main(String[] args) {
        try {
            tenDown();
        } catch (InterruptedException e) {
            e.printStackTrace();
        }

        //打印当前系统时间
        Date date = 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(date));
                date = 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;
            }
        }
    }
}