java  中ThreadLocal实例分析

java  中ThreadLocal实例分析

从概念上理解，threadlocal使变量在多个线程中相互隔离实现线程安全，threadlocal包装的变量最终都专属于对应的每个线程，线程之间相互独立，用一个具体实现来说明：

public interface Consumer {  int consume();}public class ComsumeThread implements Runnable {  private Consumer consumer;  public ComsumeThread(Consumer consumer) {    this.consumer = consumer;  }  @Override  public void run() {    for(int i=0;i<10;i++){      System.out.println(Thread.currentThread().getName()+" After Consume left:"+consumer.consume());    }  }}public class ConsumeClientA implements Consumer {  private static int leftNum = 30;  @Override  public int consume() {    int orgLeftNum = leftNum;    Random random = new Random(System.currentTimeMillis());    try {      Thread.sleep(random.nextInt(3));    } catch (InterruptedException e) {      e.printStackTrace();    }    orgLeftNum = orgLeftNum -1;    leftNum = orgLeftNum;    return leftNum;  }  public static void main(String[] args){    Consumer consumer = new ConsumeClientA();    Thread thread1 = new Thread(new ComsumeThread(consumer));    Thread thread2 = new Thread(new ComsumeThread(consumer));    Thread thread3 = new Thread(new ComsumeThread(consumer));    thread1.start();    thread2.start();    thread3.start();  }}