同步工具之ExChanger

    可以在对中对元素进行配对和交换的线程的同步点。每个线程将条目上的某个方法呈现给 exchange 方法，与伙伴线程进行匹配，并且在返回时接收其伙伴的对象。Exchanger 可能被视为 SynchronousQueue 的双向形式。Exchanger 可能在应用程序（比如遗传算法和管道设计）中很有用。
    
    

public class ExchangerTest {

    public static void main(String[] args) {
        ExecutorService service = Executors.newCachedThreadPool();
        final Exchanger exchanger = new Exchanger();
        service.execute(new Runnable(){
            public void run() {
                try {

                    String data1 = "zxx";
                    System.out.println("线程" + Thread.currentThread().getName() +
                    "正在把数据" + data1 +"换出去");
                    Thread.sleep((long)(Math.random()*10000));
                    String data2 = (String)exchanger.exchange(data1);
                    System.out.println("线程" + Thread.currentThread().getName() +
                    "换回的数据为" + data2);
                }catch(Exception e){

                }
            }
        });
        service.execute(new Runnable(){
            public void run() {
                try {

                    String data1 = "lhm";
                    System.out.println("线程" + Thread.currentThread().getName() +
                    "正在把数据" + data1 +"换出去");
                    Thread.sleep((long)(Math.random()*10000));
                    String data2 = (String)exchanger.exchange(data1);
                    System.out.println("线程" + Thread.currentThread().getName() +
                    "换回的数据为" + data2);
                }catch(Exception e){

                }
            }
        });
    }
}

结果：

线程pool-1-thread-2正在把数据lhm换出去
线程pool-1-thread-1正在把数据zxx换出去
线程pool-1-thread-1换回的数据为lhm
线程pool-1-thread-2换回的数据为zxx