package com.ljq.test.thread;
 
import java.util.Random;
 
/**
 * ThreadLocal類及應(yīng)用技巧
 *
 * 將線程范圍內(nèi)共享數(shù)據(jù)進(jìn)行封裝，封裝到一個單獨(dú)的數(shù)據(jù)類中，提供設(shè)置獲取方法
 * 將該類單例化，提供獲取實(shí)例對象的方法，獲取到的實(shí)例對象是已經(jīng)封裝好的當(dāng)前線程范圍內(nèi)的對象
 */
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 myData = new MyThreadScopeData();
          myData.setName("name" + data);
          myData.setAge(data);
          myThreadScopeData.set(myData);
          */
          MyThreadScopeData.getThreadInstance().setName("name" + data);
          MyThreadScopeData.getThreadInstance().setAge(data);
          new A().get();
          new B().get();
        }
      }).start();
    }
  }
   
  //使用獲取到的線程范圍內(nèi)的對象實(shí)例調(diào)用相應(yīng)方法
  static class A{
    public void get(){
      int data = x.get();
      System.out.println("A from " + Thread.currentThread().getName() + " get data :" + data);
       
      /*     
      MyThreadScopeData myData = myThreadScopeData.get();
      System.out.println("A from " + Thread.currentThread().getName()
          + " getMyData: " + myData.getName() + "," + myData.getAge());
      */
      MyThreadScopeData myData = MyThreadScopeData.getThreadInstance();
      System.out.println("A from " + Thread.currentThread().getName()
          + " getMyData: " + myData.getName() + "," + myData.getAge());
    }
  }
   
  //使用獲取到的線程范圍內(nèi)的對象實(shí)例調(diào)用相應(yīng)方法
  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 {
 
  // 單例
  private MyThreadScopeData() {
  }
 
  // 提供獲取實(shí)例方法，不加synchronized關(guān)鍵字表示線程各拿各自的數(shù)據(jù)，互不干擾
  public static/* synchronized */MyThreadScopeData getThreadInstance() {
    // 從當(dāng)前線程范圍內(nèi)數(shù)據(jù)集中獲取實(shí)例對象
    MyThreadScopeData instance = map.get();
    if (instance == null) {
      instance = new MyThreadScopeData();
      map.set(instance);
    }
    return instance;
  }
 
  // 將實(shí)例對象存入當(dāng)前線程范圍內(nèi)數(shù)據(jù)集中
  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;
  }
}