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标题: ThreadLocal的使用 [打印本页]

作者: 杨静    时间: 2012-10-20 10:23
标题: ThreadLocal的使用
public class ThreadLocalTest {
private static ThreadLocal<Integer> x = new ThreadLocal<Integer>();
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(){
    @Override
    public void run() {
     int data = new Random().nextInt();
     System.out.println(Thread.currentThread().getName()
       + " has put data :" + data);
     x.set(data);
     MyThreadScopeData.getThreadInstance().setName("name" + data);
     MyThreadScopeData.getThreadInstance().setAge(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()
     + " get data :" + data);
   MyThreadScopeData myData = MyThreadScopeData.getThreadInstance();
   System.out.println("A from " + Thread.currentThread().getName()
     + " getMyData: " + myData.getName() + "," +
     myData.getAge());
  }
}

static class B{
  public void get(){
   int data = x.get();   
   System.out.println("B from " + Thread.currentThread().getName()
     + " get data :" + data);
   MyThreadScopeData myData = MyThreadScopeData.getThreadInstance();
   System.out.println("B from " + Thread.currentThread().getName()
     + " getMyData: " + myData.getName() + "," +
     myData.getAge());   
  }  
}
}

class MyThreadScopeData{
private MyThreadScopeData(){}
public static MyThreadScopeData getThreadInstance(){
  MyThreadScopeData instance = map.get();
  if(instance == null){
   instance = new MyThreadScopeData();
   map.set(instance);
  }
  return instance;
}
private static ThreadLocal<MyThreadScopeData> map = new ThreadLocal<MyThreadScopeData>();

private String name;
private int age;
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;
}
}
在这个程序中x,myThreadScopeData两个是ThreadLocal型的变量,那么在线程运行中,是每个线程创建一个此种类型的变量呢?还是共享?






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