public static void main(String[] args) {
ExecutorService service = Executors.newCachedThreadPool(); //创建一个线程池
final CountDownLatch cdOrder = new CountDownLatch(1);//指挥官的命令,设置为1,指挥官一下达命令,则cutDown,变为0,战士们执行任务
final CountDownLatch cdAnswer = new CountDownLatch(3);//因为有三个战士,所以初始值为3,每一个战士执行任务完毕则cutDown一次,当三个都执行完毕,变为0,则指挥官停止等待。
for(int i=0;i<20;i++){
Runnable runnable = new Runnable(){
public void run(){
try {
System.out.println("线程" + Thread.currentThread().getName() +
"正准备接受命令");
cdOrder.await(); //战士们都处于等待命令状态
System.out.println("线程" + Thread.currentThread().getName() +
"已接受命令");
Thread.sleep((long)(Math.random()*10000));
System.out.println("线程" + Thread.currentThread().getName() +
"回应命令处理结果");
} catch (Exception e) {
e.printStackTrace();
} finally {
cdAnswer.countDown(); //任务执行完毕,返回给指挥官,cdAnswer减1。
}
}
};
service.execute(runnable);//为线程池添加任务
}
try {
Thread.sleep((long)(Math.random()*10000));
System.out.println("线程" + Thread.currentThread().getName() +
"即将发布命令");
cdOrder.countDown(); //发送命令,cdOrder减1,处于等待的战士们停止等待转去执行任务。
System.out.println("线程" + Thread.currentThread().getName() +
"已发送命令,正在等待结果");
cdAnswer.await(); //命令发送后指挥官处于等待状态,一旦cdAnswer为0时停止等待继续往下执行
System.out.println("线程" + Thread.currentThread().getName() +
"已收到所有响应结果");
} catch (Exception e) {
e.printStackTrace();
} finally {
}
service.shutdown(); //任务结束,停止线程池的所有线程
}