1 package com.runnabledemo;
 2 
 3 public class waitnotifydemo01 {
 4     public static void main(String[]args)throws Exception {
 5         final Object obj = new Object();
 6         Thread t1 = new Thread() {
 7             public void run() {
 8                 synchronized (obj) {
 9                     try {
10                         obj.wait();
11                         System.out.println("Thread 1 wake up.");
12                     } catch (InterruptedException e) {
13                     }
14                 }
15             }
16         };
17         t1.start();
18         Thread.sleep(1000);//We assume thread 1 must start up within 1 sec.
19         Thread t2 = new Thread() {
20             public void run() {
21                 synchronized (obj) {
22                     obj.notifyAll();
23                     System.out.println("Thread 2 sent notify.");
24                 }
25             }
26         };
27         t2.start();
28     }
29 }