线程互斥与同步

能解决下面的问题，基本上就能理解线程互斥与同步了。

子线程循环10次，主线程循环100次，接着子线程循环10，主线程循环100次。如此往复循环50次。

 1 package cn.lah.thread;
 2
 3 public class TraditionalThreadCommunication {
 4
 5     public static void main(String[] args) {
 6
 7         final Business business = new Business();
 8         new Thread(new Runnable() {
 9             public void run() {
10                 for (int i = 1; i <= 50; i++) {
11                     business.sub(i);
12                 }
13             }
14         }).start();
15
16         for (int i = 1; i <= 50; i++) {
17             business.main(i);
18         }
19
20     }
21
22 }
23
24 //定义一个业务逻辑类，将线程同步相关的方法归于本类，这种设计可以实现高内聚，并能增强代码的健壮性
25 class Business {
26
27     private boolean beShouldSub = true;
28
29     public synchronized void sub(int i) {
30         while (!beShouldSub) {
31             try {
32                 this.wait();
33             } catch (InterruptedException e) {
34                 e.printStackTrace();
35             }
36         }
37         for (int j = 1; j <= 10; j++) {
38             System.out.println("sub Thread" + j + " loop" + i);
39         }
40         beShouldSub = false;
41         this.notify();
42     }
43
44     public synchronized void main(int i) {
45         while (beShouldSub) {
46             try {
47                 this.wait();
48             } catch (InterruptedException e) {
49                 e.printStackTrace();
50             }
51         }
52         for (int j = 1; j <= 100; j++) {
53             System.out.println("main Thread" + j + " loop" + i);
54         }
55         beShouldSub = true;
56         this.notify();
57     }
58 }