Java线程：线程的交互

本文转载至：http://lavasoft.blog.51cto.com/62575/99157

package com.mbl.main;

import com.mbl.MyThread;

public class ThreadDemo {

	public static void main(String[] args) {
		// TODO Auto-generated method stub
		MyThread thread = new MyThread(); 
        //启动计算线程 
		thread.start(); 
		//线程A拥有b对象上的锁。线程为了调用wait()或notify()方法，该线程必须是那个对象锁的拥有者 
		synchronized(thread){ 
            try { 
                System.out.println("等待对象b完成计算。。。"); 
                //当前线程A等待 
                thread.wait(); 
            } catch (InterruptedException e) { 
                e.printStackTrace(); 
            } 
            System.out.println("b对象计算的总和是：" + thread.total); 
		}
	}

}

package com.mbl;

public class MyThread extends Thread {
	
	public int total;

	@Override
	public void run() {
		// TODO Auto-generated method stub
		 synchronized (this) { 
	            for (int i = 0; i < 101; i++) { 
	                total += i; 
	            } 
	            //（完成计算了）唤醒在此对象监视器上等待的单个线程，在本例中线程A被唤醒 
	            notify(); 
	        } 
	}
	
	

}

package com.mbl.main;


import com.mbl.message.Message;
import com.mbl.message.Notifier;
import com.mbl.message.Waiter;

public class RunnableDemo {

	public static void main(String[] args) {
		// TODO Auto-generated method stub
		    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();
	   
	}

}

package com.mbl.message;

import java.io.Serializable;

public class Message implements Serializable {

	/**
	 * 
	 */
	private static final long serialVersionUID = 1L;

	private String message;

	public Message(String message) {
		super();
		this.message = message;
	}

	public String getMessage() {
		return message;
	}

	public void setMessage(String message) {
		this.message = message;
	}

}

package com.mbl.message;

public class Notifier implements Runnable {
	private Message msg;

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

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

}

package com.mbl.message;

public class Waiter implements Runnable {
	private Message msg;

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

	@Override
	public void run() {
		// TODO Auto-generated method stub
		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.getMessage());
		}
	}

}

notify()

waiter waiting to get notified at time:1492417006932
waiter1 waiting to get notified at time:1492417006933
notifier started
waiter waiter thread got notified at time:1492417007934
waiter processed: notifier Notifier work done

如果我们注释掉Notifier类中的notify() 方法的调用，并打开notifyAll() 方法的调用，将会有以下的输出信息。

notifyAll()

waiter waiting to get notified at time:1492417072173
waiter1 waiting to get notified at time:1492417072173
notifier started
waiter1 waiter thread got notified at time:1492417073175
waiter1 processed: notifier Notifier work done
waiter waiter thread got notified at time:1492417073175
waiter processed: notifier Notifier work done