之前线程共享，使用的是map来实现的，JDK本身就有一个实现机制叫做ThreadLocal。看下面这段代码是如何实现的。
public class ThreadLocalTest { private static ThreadLocal<MyThreadScopeData> myThreadScopeData=new ThreadLocal<MyThreadScopeData>(); public static void main(String[] args){ for(int i=0;i<2;i++) { new Thread(new Runnable(){ public void run(){ int data=new Random().nextInt(); System.out.println(Thread.currentThread().getName() +"has put data:"+data); MyThreadScopeData.getInstance().setName("name"+data); MyThreadScopeData.getInstance().setAge(data); new A().get(); new B().get(); } }).start(); } } static class A{ public void get(){ MyThreadScopeData myData=MyThreadScopeData.getInstance(); System.out.println("A from"+Thread.currentThread().getName() +" getMyData: "+myData.getName()+" , "+myData.getAge()); } } static class B{ public void get(){ MyThreadScopeData myData=MyThreadScopeData.getInstance(); System.out.println("B from"+Thread.currentThread().getName() +" getMyData: "+myData.getName()+" , "+myData.getAge()); } } } class MyThreadScopeData{ private MyThreadScopeData(){}; private static ThreadLocal<MyThreadScopeData> map=new ThreadLocal<MyThreadScopeData>(); public static MyThreadScopeData getInstance(){ MyThreadScopeData instance=map.get(); if(instance==null){ instance=new MyThreadScopeData(); map.set(instance); } return instance; } private String name; public String getName() { return name; } public void setName(String name) { this.name = name; } public int getAge() { return age; } public void setAge(int age) { this.age = age; } private int age; }
