Java多线程之生产者消费者demo

package com.ccy.thread.demo;

class ProducerConsumerDemo
{
public static void main(String[] args)
{
Resource r = new Resource();

Producer pro = new Producer(r);
Consumer con = new Consumer(r);

Thread t3 = new Thread(con);
Thread t4 = new Thread(con);

new Thread(pro).start();
new Thread(pro).start();
t3.start();
t4.start();

}
}

/*
对于多个生产者和消费者。
为什么要定义while判断标记。
原因：让被唤醒的线程再一次判断标记。

为什么定义notifyAll，
因为需要唤醒对方线程。
因为只用notify，容易出现只唤醒本方线程的情况。导致程序中的所有线程都等待。

*/

class Resource{

private String name;
private int count = 1;
private boolean flag = false;
//  t1    t2
public synchronized void set(String name)
{
while(flag){
try{
this.wait();
}catch(Exception e){
e.printStackTrace();
}
}

this.name = name+"--"+count++;
System.out.println(Thread.currentThread().getName()+"...生产者.."+this.name);
flag = true;
this.notifyAll();
}

//  t3   t4
public synchronized void out()
{
while(!flag){
try{
wait();
}catch(Exception e){
e.printStackTrace();
}
}

System.out.println(Thread.currentThread().getName()+"...消费者........."+this.name);
flag = false;
this.notifyAll();
}
}

class Producer extends Thread
{
private Resource res;

Producer(Resource res)
{
this.res = res;
}
public void run()
{
while(true)
{
res.set("+生产商品+");

}
}
}

class Consumer implements Runnable
{
private Resource res;

Consumer(Resource res)
{
this.res = res;
}
public void run()
{
while(true)
{
res.out();
}
}
}