/**
* 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,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;
- public synchronized void set(String name)
- {
- while(flag)
- try{
- wait();
- }catch(Exception e){
-
- }
- this.name = name+"--"+count++;
- System.out.println(Thread.currentThread().getName()+"...生产者.."+this.name);
- flag = true;
- this.notifyAll();
- }
- public synchronized void out()
- {
- while(!flag)
- try{
- wait();
- }catch(Exception e){
-
- }
- System.out.println(Thread.currentThread().getName()+"...消费者........."+this.name);
- flag = false;
- this.notifyAll();
- }
- }
- class Producer implements Runnable
- {
- private Resource res;
- Producer(Resource res)
- {
- this.res = res;
- }
- public void run()
- {
- while(true)
- {
- res.set("+商品+");
- }
- }
- }
- class Consumer implements Runnable
- {
- private Resource res;
- Consumer(Resource res)
- {
- this.res = res;
- }
- public void run()
- {
- while(true)
- {
- res.out();
- }
- }
- }
- class ProducerConsumerDemo
- {
- public static void main(String[] args)
- {
- Resource r = new Resource();
- Producer pro = new Producer(r);
- Consumer con = new Consumer(r);
- Thread t1 = new Thread(pro);
- Thread t2 = new Thread(pro);
- Thread t3 = new Thread(con);
- Thread t4 = new Thread(con);
- t1.start();
- t2.start();
- t3.start();
- t4.start();
- }
- }
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