首先定义 ： 一个线程A在占有CPU资源期间 ，可以让其他线程调用join()和本线程联合。
嗯哈，像书本这个列子：
如： B.join();
我们称A在运行期间联合了B, 如果线程A在占有CPU资源期间一旦联合B线程，那么A线程将立刻
中断执行，一直等到它联合的线程B执行完毕，A线程再重新排队等待CPU资源，以便恢复执行，
如果A准备联合的B线程已经结束，那么B.join()，不会产生任何效果。
代码语言：javascript复制 1 package dialog_color;
2
3 public class Example12_8
4 {
5 public static void main(String args [])
6 {
7 ThreadJoin a = new ThreadJoin();
8 Thread customer = new Thread(a);
9 Thread cakeMaker = new Thread(a);
10 customer.setName("顾客");
11 cakeMaker.setName("蛋糕");
12 a.setJoinThread(cakeMaker);
13 customer.start();
14 }
15 }
16 class ThreadJoin implements Runnable
17 {
18 Cake cake;
19 Thread joinThread;
20 public void setJoinThread(Thread it)
21 {
22 this.joinThread=it;
23 }
24 public void run() {
25 // TODO Auto-generated method stub
26 if(Thread.currentThread().getName().equals("顾客"))
27 {
28 System.out.println(Thread.currentThread().getName()
29 "等待" joinThread.getName() "制作生日蛋糕");
30 try {
31 joinThread.start();
32 joinThread.join();
33
34 } catch (InterruptedException e) {
35 // TODO Auto-generated catch block
36 // e.printStackTrace();
37 }
38 System.out.println(Thread.currentThread().getName() "买了" cake.name "价钱: " cake.price);
39 }
40 else if(Thread.currentThread()==joinThread)
41 {
42 System.out.println(joinThread.getName() "开始制作生日蛋糕，请等待......");
43 try {
44 Thread.sleep(2000);
45 } catch (InterruptedException e) {
46 // TODO Auto-generated catch block
47 e.printStackTrace();
48 }
49 cake=new Cake("生日蛋糕",158);
50 System.out.println(joinThread.getName() "制作完成！");
51 }
52 }
53
54 class Cake //内部类 相当于一个结构体） (c/c )
55 {
56 int price ;
57 String name;
58 Cake(String name ,int price)
59 {
60 this.name=name;
61 this.price=price;
62 }
63 }
64 }效果图：
code:
代码语言：javascript复制 1 package tes;
2 /*
3 * 模拟这样一个过程
4 * 一个老头去买蛋糕，蛋糕需要先做，
5 * 老头等待做完，然后付款离开。
6 *
7 * */
8 public class Example12_9 {
9
10 public static void main(String args [])
11 {
12 Thread aa,bb;
13 JoinThread hehe = new JoinThread();
14 aa = new Thread(hehe);
15 bb = new Thread(hehe);
16 aa.setName("老头");
17 bb.setName("蛋糕师傅");
18 hehe.setJoinThread(bb);
19 aa.start();
20 }
21 }
22 class JoinThread implements Runnable
23 {
24 Thread myThread;
25 cake mycake;
26 public void setJoinThread(Thread name) {
27 myThread=name;
28 }
29 @Override
30 public void run() {
31 // TODO Auto-generated method stub
32 if(Thread.currentThread().getName().equals("老头"))
33 {
34 print(Thread.currentThread().getName() "等待蛋糕师傅制作蛋糕"
35 myThread.currentThread().getName() "开始制作蛋糕.....");
36 //开始联合同步
37 myThread.start();
38 try {
39 myThread.join();
40 } catch (InterruptedException e) {
41 // TODO Auto-generated catch block
42 e.printStackTrace();
43 }
44 print(myThread.currentThread().getName() "蛋糕做完..."
45 Thread.currentThread().getName() "买了" mycake.name
46 " 价钱：" mycake.price);
47 }
48 else if(Thread.currentThread()==myThread)
49 {
50 print(myThread.currentThread().getName()
51 "开始制作蛋糕,wait for minutes !");
52 try {
53 Thread.sleep(2500);
54 } catch (InterruptedException e) {
55 // TODO Auto-generated catch block
56 e.printStackTrace();
57 }
58 print("蛋糕做完了");
59 mycake = new cake("蛋糕",12.8);
60 }
61 }
62 private void print(String name){
63 System.out.println(name);
64 }
65 class cake
66 {
67 String name;
68 double price;
69 cake(String name,double price){
70 this.name=name;
71 this.price=price;
72 }
73 }
74 }
