java线程的等待、通知机制【读书笔记】

package com.baidu.nuomi.concurrent;

import java.text.SimpleDateFormat;
import java.util.Date;
import java.util.concurrent.TimeUnit;

/**
 * Created by sonofelice on 16/6/18.
 */
public class WaitNotify {
    static boolean flag = true;
    static Object lock = new Object();

    public static void main(String[] args) throws Exception{
        Thread waitThread = new Thread(new Wait(),"WaitThread");
        waitThread.start();
        TimeUnit.SECONDS.sleep(1);
        Thread notifyThread = new Thread(new Notify(),"NotifyThread");
        notifyThread.start();
        
    }
    static class Wait implements Runnable{
        @Override
        public void run() {
            synchronized (lock){
                while (flag){
                    try {
                        System.out.println(Thread.currentThread() + " flag is true. wait @ "
                                + new SimpleDateFormat("HH:mm:ss").format(new Date()));
                        lock.wait();
                    }catch (InterruptedException e){
                    }
                }
                System.out.println(Thread.currentThread() + "flag is false. running @ "
                        + new SimpleDateFormat("HH:mm:ss").format(new Date()));
            }
        }
    }
    static class Notify implements Runnable{
        @Override
        public void run() {
            synchronized (lock){
                System.out.println(Thread.currentThread() + "hold lock. notify @ "
                        + new SimpleDateFormat("HH:mm:ss").format(new Date()));
                lock.notifyAll();
                flag = false;
                SleepUtils.second(5);
            }
            synchronized (lock){
                System.out.println(Thread.currentThread() + "hold lock again. sleep @ "
                        + new SimpleDateFormat("HH:mm:ss").format(new Date()));
                SleepUtils.second(5);
            }
        }
    }
}

Thread[WaitThread,5,main] flag is true. wait @ 12:21:04
Thread[NotifyThread,5,main]hold lock. notify @ 12:21:05
Thread[NotifyThread,5,main]hold lock again. sleep @ 12:21:10
Thread[WaitThread,5,main]flag is false. running @ 12:21:15

Process finished with exit code 0