多线程_线程范围内数据共享

                   线程内的数据共享

   1需求：①线程1的A模块和B模块只能操作属于线程1的相同数据

          ② 线程2的A模块和B模块只能操作属于线程2的相同数据。 

   2、实现机制

  ①使用ThreadLocal实现线程内的数据共享,其实它内部就是一个Map

  ②通过一个Map<Thread,Object> 来存放与读取对应Thread的数据Object

3、代码

 ①Map方式：

import java.util.HashMap;import java.util.Map;import java.util.Random;public class ThreadScopeShareData {//将线程和其数据放入一个Map里面存起来private static Map<Thread,Integer> threadData=new HashMap<Thread,Integer>();public static void main(String[] args) {for(int i=0;i<2;i++){new Thread(new Runnable(){@Overridepublic void run() {int data=new Random().nextInt();System.out.println(Thread.currentThread().getName()+" has put data: "+ data);threadData.put(Thread.currentThread(), data);new A().get();new B().get();}}).start();}}static class A{public  void get(){    int data=threadData.get(Thread.currentThread());System.out.println("A from"+Thread.currentThread().getName()+" has get data: "+data);}}static class B{public  void get(){int data=threadData.get(Thread.currentThread());System.out.println("B from"+Thread.currentThread().getName()+" has get data: "+data);}}}

②使用ThreadLocal类

import java.util.Random;public class ThreadLocalTest {//使用ThreadLocal实现线程内的数据共享,其实它内部就是一个Mapprivate static ThreadLocal<Integer> x=new ThreadLocal<Integer>();public static void main(String[] args) {for(int i=0;i<3;i++){new Thread(new Runnable(){@Overridepublic void run() {int data=new Random().nextInt();System.out.println(Thread.currentThread().getName()+" has put data: "+ data);x.set(data);new A().get();new B().get();}}).start();}}static class A{public  void get(){    int data=x.get();System.out.println("A from"+Thread.currentThread().getName()+" has get data: "+data);}}static class B{public  void get(){int data=x.get();System.out.println("B from"+Thread.currentThread().getName()+" has get data: "+data);}}}