1、简介

Exchange位于 java .util.concurrent包下面，主要是用于 线程 之间数据交换的工具类，经常用于管道设计和遗传算法中。Exchange提供了一个同步点，在这个同步点上，线程完成配对并进行数据的交换。第一个线程调用exchange()方法时传入对象，它会一直等待，直到第二个对象调用exchange()方法时，每个线程的exchange()方法将返回并且接收到匹配线程传入到exchange()方法中的对象，完成数据的交换。

可以将Exchange看做是一个双向数据传输的SynchronousQueue。

2、代码示例

 package com.anzy.cloud.admin.test.thead;
 
import java.util.concurrent.Exchanger;
 
public class Bike extends Thread {
    private Exchanger<String> exchanger;
 
    public Bike(Exchanger<String> exchanger) {
        super();
        this.exchanger = exchanger;
    }
 
    @ Override 
    public void run() {
        try {
            String[] aa = {"1","2","3"};
            for (String a:aa){
                System.out.println(Thread.currentThread().getName() + ":Bike: " + exchanger.exchange(a));
                exchanger.exchange("");
            }
        } catch (InterruptedException e) {
            e.printStackTrace();
        }
    }
 
    public static void main(String[] args) {
        Exchanger<String> exchanger = new Exchanger<>();
        Car car = new Car(exchanger);
        Bike bike = new Bike(exchanger);
        car. start ();
        bike.start();
        System.out.println("Main end!");
    }
}
  

 package com.anzy.cloud.admin.test.thead;
 
import java.util.concurrent.Exchanger;
 
public class Car extends Thread {
    private Exchanger<String> exchanger;
 
    public Car(Exchanger<String> exchanger) {
        super();
        this.exchanger = exchanger;
    }
 
    @Override
    public void run() {
        try {
            String[] aa = {"a","b","c"};
            for (String a:aa){
                System.out.println(Thread.currentThread().getName() + ":Car: " + exchanger.exchange(a));
                exchanger.exchange("");
            }
        } catch (InterruptedException e) {
            e.printStackTrace();
        }
    }
}
  

运行输出结果

 Thread-1:Bike: a
Main end!
Thread-0:Car: 1
Thread-1:Bike: b
Thread-0:Car: 2
Thread-0:Car: 3
Thread-1:Bike: c