Java Wait Notify

概念

所有对象继承Object方法
用于同步资源锁控制等待以及唤醒

Demo：
Message 类同步资源
Waiter 持有Msg，New两个线程Waiter等待
Notifier 持有Msg，通过Msg通知Waiter线程继续

实战

package com.example.demo.java.base.wait;

/**
 * message 锁资源
 * waiter 等待者
 * notifier 通知者
 * @author kyle
 * @date 2023/12/17
 */
public class Client {
    public static void main(String[] args) {
        Message msg = new Message("process it");
        Waiter waiter = new Waiter(msg);
        new Thread(waiter,"waiter").start();

        Waiter waiter1 = new Waiter(msg);
        new Thread(waiter1, "waiter1").start();

        Notifier notifier = new Notifier(msg);
        new Thread(notifier, "notifier").start();
        System.out.println("All the threads are started");
    }

    public static class Message {
        private String msg;

        public Message(String str){
            this.msg=str;
        }

        public String getMsg() {
            return msg;
        }

        public void setMsg(String str) {
            this.msg=str;
        }

    }

    public static class Waiter implements Runnable {

        private Message msg;

        public Waiter(Message m){
            this.msg=m;
        }

        @Override
        public void run() {
            String name = Thread.currentThread().getName();
            synchronized (msg) {
                try{
                    System.out.println(name+" waiting to get notified at time:"+System.currentTimeMillis());
                    msg.wait();
                }catch(InterruptedException e){
                    e.printStackTrace();
                }
                System.out.println(name+" waiter thread got notified at time:"+System.currentTimeMillis());
                //process the message now
                System.out.println(name+" processed: "+msg.getMsg());
            }
        }

    }

    public static class Notifier implements Runnable {

        private Message msg;

        public Notifier(Message msg) {
            this.msg = msg;
        }

        @Override
        public void run() {
            String name = Thread.currentThread().getName();
            System.out.println(name+" started");
            try {
                Thread.sleep(1000);
                synchronized (msg) {
                    msg.setMsg(name+" Notifier work done");
                    msg.notify();
                    // msg.notifyAll();
                }
            } catch (InterruptedException e) {
                e.printStackTrace();
            }

        }

    }
}

输出结果