Exchanger

Exchanger（交换者），它是用于线程间的协作工具类，主要用于线程间数据的交换。它提供了一个同步点，在这个同步点，两个线程可以交换彼此的数据。

 

代码如下：

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public class ExchangerTest {       private static final Exchanger<String> exchanger = new Exchanger<>();     private static ExecutorService threadPool = Executors.newFixedThreadPool(2);     public static void main(String[] args) {         threadPool.execute(new Runnable() {             @Override             public void run() {                 String a = "aaaaaaaaaa";                 try {                     String b = exchanger.exchange(a);                     System.out.println("---" + b);                 } catch (InterruptedException e) {                     e.printStackTrace();                 }             }         });             threadPool.execute(new Runnable() {             @Override             public void run() {                 try {                     String b = "bbbbbbbb";                     String a = exchanger.exchange("bababa");                     System.out.println("a is " + a + " , b is " + b);                 } catch (InterruptedException e) {                     e.printStackTrace();                 }             }         });         threadPool.shutdown();     }       }

 

输出如下：

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1 2	a is aaaaaaaaaa , b is bbbbbbbb ---bababa

　　

注意点
1、Exchanger只能作用于两个线程之间，如果作用于第三个线程，则第三个线程一直处于等待中；
2、exchange中还有一个重载函数，接收一个等待时长，用于避免一直等待。

 

参考： https://blog.csdn.net/qq_27828675/article/details/114068266