package org.rui.thread.block;import java.util.Timer;import java.util.TimerTask;import java.util.concurrent.ExecutorService;import java.util.concurrent.Executors;import java.util.concurrent.TimeUnit;public class NotifyVsNotifyAll { public static void main(String[] args) throws InterruptedException { ExecutorService exec = Executors.newCachedThreadPool(); for (int i = 0; i < 5; i++) { exec.execute(new Task()); } exec.execute(new Task2()); Timer timer = new Timer(); // 安排指定的任务在指定的延迟后開始进行反复的固定速率运行。 timer.scheduleAtFixedRate(new TimerTask() { boolean prod = true; public void run() { if (prod) { System.out.println("\n notify() "); Task.blocker.prod();// prod = false; } else { System.out.println("\n notifyAll()"); Task.blocker.prodAll(); prod = true; } } }, 400, 400); TimeUnit.SECONDS.sleep(5);// run for a while... timer.cancel();// 终止此计时器， System.out.println("\n Timer canceled"); TimeUnit.MILLISECONDS.sleep(500); System.out.println("Task.blocker.prodAll()"); Task2.blocker.prodAll();//唤醒task2 不包含不论什么在Task.blocker中的锁上等待的任务 TimeUnit.MILLISECONDS.sleep(500); System.out.println("\nshutting down"); exec.shutdownNow(); }}class Blocker { synchronized void waitingCall() { try { while (!Thread.interrupted()) { wait(); System.out.println(Thread.currentThread() + " "); } } catch (InterruptedException e) { // ok to exit this way } } synchronized void prod() { notify();//在众多等候同一个锁的任务中。仅仅有一个会被唤醒，因此假设你希望使用nofify ，就必须保证被唤醒的是恰当的任务 } synchronized void prodAll() { notifyAll();//仅仅有等待这个锁的任务才会被唤醒 }}// class Task implements Runnable { static Blocker blocker = new Blocker(); public void run() { blocker.waitingCall(); }}// class Task2 implements Runnable { // a separate blocker object 一个单独的拦截器对象 static Blocker blocker = new Blocker(); public void run() { blocker.waitingCall(); //System.out.println(Thread.currentThread()+" : Task 不会被换醒Task2"); }}/** * output: * notify() Thread[pool-1-thread-2,5,main] notifyAll()Thread[pool-1-thread-2,5,main] Thread[pool-1-thread-5,5,main] Thread[pool-1-thread-4,5,main] Thread[pool-1-thread-3,5,main] Thread[pool-1-thread-1,5,main] notify() Thread[pool-1-thread-2,5,main] notifyAll()Thread[pool-1-thread-2,5,main] Thread[pool-1-thread-1,5,main] Thread[pool-1-thread-3,5,main] Thread[pool-1-thread-4,5,main] Thread[pool-1-thread-5,5,main] notify() Thread[pool-1-thread-2,5,main] notifyAll()Thread[pool-1-thread-2,5,main] Thread[pool-1-thread-5,5,main] Thread[pool-1-thread-4,5,main] Thread[pool-1-thread-3,5,main] Thread[pool-1-thread-1,5,main] notify() Thread[pool-1-thread-2,5,main] notifyAll()Thread[pool-1-thread-2,5,main] Thread[pool-1-thread-1,5,main] Thread[pool-1-thread-3,5,main] Thread[pool-1-thread-4,5,main] Thread[pool-1-thread-5,5,main] notify() Thread[pool-1-thread-2,5,main] notifyAll()Thread[pool-1-thread-2,5,main] Thread[pool-1-thread-5,5,main] Thread[pool-1-thread-4,5,main] Thread[pool-1-thread-3,5,main] Thread[pool-1-thread-1,5,main] notify() Thread[pool-1-thread-2,5,main] notifyAll()Thread[pool-1-thread-2,5,main] Thread[pool-1-thread-1,5,main] Thread[pool-1-thread-3,5,main] Thread[pool-1-thread-4,5,main] Thread[pool-1-thread-5,5,main] Timer canceledTask.blocker.prodAll()Thread[pool-1-thread-6,5,main] shutting down*/ 
