Exchanger允许两个线程在集合点交换对象，它在多流水线设计中是有用的
例子：线程间的数据交换，比如：两个人约定在某个地点交易，一手交钱，一手交货，当一个人先到指定地点，则这个人在此处等着，直到另一人到达此处才完成交易
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){
}
}
});
}
}