java中的sleep()和wait()的区别

 1 /**
 2  * 
 3  */
 4 package com.b510.test;
 5 
 6 /**
 7  * java中的sleep()和wait()的区别
 8  * @author Hongten
 9  * @date 2013-12-10
10  */
11 public class TestD {
12 
13     public static void main(String[] args) {
14         new Thread(new Thread1()).start();
15         try {
16             Thread.sleep(5000);
17         } catch (Exception e) {
18             e.printStackTrace();
19         }
20         new Thread(new Thread2()).start();
21     }
22     
23     private static class Thread1 implements Runnable{
24         @Override
25         public void run(){
26             synchronized (TestD.class) {
27             System.out.println("enter thread1...");    
28             System.out.println("thread1 is waiting...");
29             try {
30                 //调用wait()方法，线程会放弃对象锁，进入等待此对象的等待锁定池
31                 TestD.class.wait();
32             } catch (Exception e) {
33                 e.printStackTrace();
34             }
35             System.out.println("thread1 is going on ....");
36             System.out.println("thread1 is over!!!");
37             }
38         }
39     }
40     
41     private static class Thread2 implements Runnable{
42         @Override
43         public void run(){
44             synchronized (TestD.class) {
45                 System.out.println("enter thread2....");
46                 System.out.println("thread2 is sleep....");
47                 //只有针对此对象调用notify()方法后本线程才进入对象锁定池准备获取对象锁进入运行状态。
48                 TestD.class.notify();
49                 //==================
50                 //区别
51                 //如果我们把代码：TestD.class.notify();给注释掉，即TestD.class调用了wait()方法，但是没有调用notify()
52                 //方法，则线程永远处于挂起状态。
53                 try {
54                     //sleep()方法导致了程序暂停执行指定的时间，让出cpu该其他线程，
55                     //但是他的监控状态依然保持者，当指定的时间到了又会自动恢复运行状态。
56                     //在调用sleep()方法的过程中，线程不会释放对象锁。
57                     Thread.sleep(5000);
58                 } catch (Exception e) {
59                     e.printStackTrace();
60                 }
61                 System.out.println("thread2 is going on....");
62                 System.out.println("thread2 is over!!!");
63             }
64         }
65     }
66 }

enter thread1...
thread1 is waiting...
enter thread2....
thread2 is sleep....
thread2 is going on....
thread2 is over!!!
thread1 is going on ....
thread1 is over!!!

1 TestD.class.notify();

enter thread1...
thread1 is waiting...
enter thread2....
thread2 is sleep....
thread2 is going on....
thread2 is over!!!