Exchanger，用于线程随机交换数据

Exchanger功能：当一个线程运行到exchange()方法时会阻塞，另一个线程运行到exchange()时，二者交换数据，然后执行后面的程序。在实际项目中使用场景很少，几乎不被使用，大家了解即可！

public static void main(String[] args) {  
    final Exchanger<Integer> exchanger = new Exchanger<Integer>();  
    for (int i = 0; i < 10; i++) {  
        final Integer num = i;  
        new Thread() {  
            public void run() {  
                System.*out*.println("我是线程：Thread_" + this.getName() + "我的数据是：" + num);  
                try {  
                    Integer exchangeNum = exchanger.exchange(num);  
                    Thread.*sleep*(1000);  
                    System.*out*.println("我是线程：Thread_" + this.getName() + "我原先的数据为：" + num + " , 交换后的数据为：" + exchangeNum);  
                } catch (InterruptedException e) {  
                    e.printStackTrace();  
                }  
            }  
        }.start();  
    }  
}