synchronized 面试题 ---- 生产者、消费者

/**
 * 面试题  ---- 生产者、消费者
 *
 */
public class TestProductorAndConsumer {

    public static void main(String[] args) {
        Clerk clerk=new Clerk();
        Productor pro=new Productor(clerk);
        Consumer cus=new Consumer(clerk);

        new Thread(pro,"生产者A").start();
        new Thread(cus,"消费者B").start();

        new Thread(pro,"生产者C").start();
        new Thread(cus,"消费者D").start();     
    }
}


class Clerk{

    private int product=0;

    //进货
    public synchronized void get(){
        while(product>=1){      //为了避免虚假唤醒 问题，应该总是使用在循环中
            System.out.println("产品已满");
            try {
                this.wait();
            } catch (InterruptedException e) {
            }
        }
        System.out.println(Thread.currentThread().getName()+" : "+ (++product));
        this.notifyAll();
    }

    public synchronized void sale(){
        while(product<=0){        //为了避免虚假唤醒 问题，应该总是使用在循环中
            System.out.println("缺货");
            try {
                this.wait();
            } catch (InterruptedException e) {
            }
        }
        System.out.println(Thread.currentThread().getName()+" : "+(--product));
        this.notifyAll();
    }
}

//生产者
class Productor implements Runnable{

    private Clerk clerk;

    public Productor(Clerk clerk){
        this.clerk=clerk;
    }

    public void run() {
        for (int i = 0; i < 20; i++) {
            clerk.get();
        }
    }   
}

//消费者
class Consumer implements Runnable{

    private Clerk clerk;

    public Consumer(Clerk clerk){
        this.clerk=clerk;
    }

    public void run() {
        for (int i = 0; i < 20; i++) {
            clerk.sale();
        }
    }   
}