## 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.lei;

import com.ning.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) {
TestThread4 testThread4 = new TestThread4();
new Thread(testThread4,"小明").start();
new Thread(testThread4,"小牛").start();
new Thread(testThread4,"小王").start();

}

}
```

```
package com.lei;

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

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(){
int num = 10;
while (true){
try {
Thread.sleep(1000);
System.out.println(num--);
if(num<=0){
break;
}
} catch (InterruptedException e) {
e.printStackTrace();
}
}
}
}
```