马老师的WoTou生产消费线程讲解例子

public class ProducerConsumer {
    public static void main(String[] args) {
        SyncStack ss = new SyncStack();
        Producer p = new Producer(ss);
        Consumer c = new Consumer(ss);
        new Thread(p).start();
        new Thread(p).start();
        new Thread(p).start();
        new Thread(c).start();
    }
}
 
//定义一个WoTou类，在类中有id以标记是哪个窝头，重写了toString方法
class WoTou {
    int id; 
    WoTou(int id) {
        this.id = id;
    }
    public String toString() {
        return "WoTou : " + id;
    }
}
 
 
//定义一个篮子的对象，用于装WoTou，在类中有push方法，用于装WoTou，pop方法，用于吃WoTou
class SyncStack {
    int index = 0;
    WoTou[] arrWT = new WoTou[6];
    /*
    *wate()只有在锁定（synchronized）的时候才能使用
    */
    //push用于装WoTou，当WoTou数达到6时wait（）休息
    public synchronized void push(WoTou wt) {
        while(index == arrWT.length) {
            try {
                this.wait();
            } catch (InterruptedException e) {
                e.printStackTrace();
            }
        }
        //唤醒瓦特（）
        this.notifyAll();       
        arrWT[index] = wt;
        index ++;
    }
     
    //pop用于吃WoTou，当WoTou数为0时wait（）
    public synchronized WoTou pop() {
        while(index == 0) {
            try {
                this.wait();
            } catch (InterruptedException e) {
                e.printStackTrace();
            }
        }
        this.notifyAll();
        index--;
        return arrWT[index];
    }
}
 
//继承Runnable接口，实现run方法的Producer类，一个对象只生产20个WoTou
class Producer implements Runnable {
    SyncStack ss = null;
    Producer(SyncStack ss) {
        this.ss = ss;
    }
     
    public void run() {
        for(int i=0; i<20; i++) {
            WoTou wt = new WoTou(i);
            ss.push(wt);
System.out.println("生产了：" + wt);
            try {
                Thread.sleep((int)(Math.random() * 200));
            } catch (InterruptedException e) {
                e.printStackTrace();
            }           
        }
    }
}
 
//继承Runnable接口，实现run方法的Consumer类，一个对象只消费20个WoTou
class Consumer implements Runnable {
    SyncStack ss = null;
    Consumer(SyncStack ss) {
        this.ss = ss;
    }
     
    public void run() {
        for(int i=0; i<20; i++) {
            WoTou wt = ss.pop();
System.out.println("消费了: " + wt);
            try {
                Thread.sleep((int)(Math.random() * 1000));
            } catch (InterruptedException e) {
                e.printStackTrace();
            }           
        }
    }
}