ThreadLocal实现线程范围内共享变量

 1 package ch03;
 2 
 3 import java.util.Random;
 4 
 5 public class ThreadLocalTest {
 6     
 7     public static void main(String[] args) {
 8         Thread th = null;
 9         for(int i=0; i<2; i++){
10             th = new Thread(new Runnable() {
11                 @Override
12                 public void run() {
13                     int data = new Random().nextInt();
14                     System.out.println(Thread.currentThread().getName()+"\t"+data);
15                     Request request = Request.getThreadInstance();
16                     request.setName("name:"+data);
17                     request.setAge(data);
18                     
19                     //输出两个模块的值
20                     new A().get();
21                     new B().get();
22                 }
23             });
24             th.start();
25         }
26     }
27     
28     /*A模块*/
29     static class A{
30         public void get(){
31             Request request = Request.getThreadInstance();
32             System.out.println("A: "+Thread.currentThread().getName()+"\t"+
33                     request.getName()+"\t"+request.getAge());
34         }
35     }
36     /*B模块*/
37     static class B{
38         public void get(){
39             Request request = Request.getThreadInstance();
40             System.out.println("B: "+Thread.currentThread().getName()+"\t"+
41                     request.getName()+"\t"+request.getAge());
42         }
43     }
44     
45 }
46 
47 class Request{
48     
49     private Request(){}
50     
51     /*ThreadLocal：将变量与当前线程绑定，相当于Map<Thread, value>*/
52     private static ThreadLocal<Request> instance = new ThreadLocal<>();
53     /*返回当前线程的单例*/
54     public static Request getThreadInstance(){
55         Request request = instance.get();
56         if(request == null){
57             request = new Request();
58             instance.set(request);
59         }
60         return request;
61     }
62     
63     private String name;
64     private int age;
65     
66     public String getName() {
67         return name;
68     }
69     public void setName(String name) {
70         this.name = name;
71     }
72     public int getAge() {
73         return age;
74     }
75     public void setAge(int age) {
76         this.age = age;
77     }
78     
79 }