多线程：一个生产者一个消费者

管程法：消费者、生产者、被消费的对象（包子） 、缓冲区（包子铺）
1.被消费的对象（包子）

package com.mutouren.demo.ex;


public class Baozi {

    //包子的编号
    private int num;

    Baozi(int num){
        this.num=num;
    }


    public int getNum() {
        return num;
    }

    public void setNum(int num) {
        this.num = num;
    }
}

2.缓冲区（包子铺）

package com.mutouren.demo.ex;


public class Hcq {

    private Baozi[] baozis = new Baozi[10];

    private int count = 0;


    
    public synchronized void pushBaozi(Baozi baozi) {
        //如果包子满了  等待消费者消费
        if (baozis.length == count) {
            //通知消费者消费
            try {
                System.out.println("生产者等待。。。。。");
                this.wait();
            } catch (InterruptedException e) {
                e.printStackTrace();
            }
        }
        System.out.println("生产者开始放。。。。。");
        //如果包子没满  则放包子
        baozis[count] = baozi;
        count++;
        try {
            Thread.sleep(10);
        } catch (InterruptedException e) {
            e.printStackTrace();
        }
        System.out.println(Thread.currentThread().getName() + "生产了第 " + baozi.getNum() + " 个包子");

        this.notifyAll();


    }


    
    public synchronized void eatBaozi() {
        //如果没有包子  等待生产者生产包子
        if (count == 0) {
            //通知消费者消费
            try {
                System.out.println("消费者等待。。。。");
                this.wait();
            } catch (InterruptedException e) {
                e.printStackTrace();
            }
        }

        //如果有  则进行消费
        System.out.println("消费者开始吃。。。。");
        count--;
        Baozi baozi = baozis[count];
//        System.out.println("count = " + count);
        try {
            Thread.sleep(10);
        } catch (InterruptedException e) {
            e.printStackTrace();
        }
        System.out.println(Thread.currentThread().getName() + "消费了第 " + baozi.getNum() + " 个包子");

        this.notifyAll();

    }
}

3.生产者

package com.mutouren.demo.ex;


public class Scz implements Runnable {

    //生产者消费者都要从缓冲区拿包子
    private Hcq hcq;

    Scz(Hcq hcq){
        this.hcq=hcq;
    }

    @Override
    public void run() {
        for (int i = 1; i <= 100; i++) {
            hcq.pushBaozi(new Baozi(i));
        }
    }
}

4.消费者

package com.mutouren.demo.ex;


public class Xfz implements Runnable {

    private Hcq hcq;

    public Xfz(Hcq hcq) {
        this.hcq=hcq;
    }

    @Override
    public void run() {
        for (int i = 0; i < 100; i++) {
            hcq.eatBaozi();
        }
    }
}

5.主类

package com.mutouren.demo.ex;


public class Test {

    public static void main(String[] args) {
        Hcq hcq = new Hcq();
        Scz scz = new Scz(hcq);
        Xfz xfz = new Xfz(hcq);
        new Thread(xfz,"消费者1").start();
        new Thread(scz,"生产者1111").start();

    }
}

结果：

总结：
1.黄色的框说明 wait会释放锁并且在再次得到锁之后 会继续从原来的地方执行，而不是从头开始
2.结果说明了 是先生产后消费的