完整代码

//仓库
class WareHouse {
    //设定库存30件
    public static int storeCount = 30;
}

public class Clerk {
    //如果Consumer是通过Runnable接口方式实现多线程，则该类设置成static
    public synchronized void consumeProducter() {

        if (WareHouse.storeCount < 20) {
            notify();
            WareHouse.storeCount++;
            System.out.println(Thread.currentThread().getName()
                    + "生产第" + WareHouse.storeCount + "个产品");

        } else {
            //等待生产
            try {
                wait();
            } catch (InterruptedException e) {
                e.printStackTrace();
            }
        }
    }
    //如果Producer是通过Runnable接口方式实现多线程，则该类设置成static
    public synchronized void produceProducter() {


        if (WareHouse.storeCount > 0) {
            notify();
            System.out.println(Thread.currentThread().getName()
                    + "消费第" + WareHouse.storeCount + "个产品");
        } else {
            //等待消费
            try {
                wait();
            } catch (InterruptedException e) {
                e.printStackTrace();
            }
        }

    }
}

class Productor extends Thread {

    Clerk clerk = new Clerk();

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

    @Override
    public void run() {
        while (true) {
            try {
                Thread.sleep(100);
            } catch (InterruptedException e) {
                e.printStackTrace();
            }
            clerk.produceProducter();
        }

    }

}

class Consumer extends Thread {
    Clerk clerk = new Clerk();

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

    @Override
    public void run() {
        while (true) {
            try {
                Thread.sleep(1000);
            } catch (InterruptedException e) {
                e.printStackTrace();
            }
            clerk.consumeProducter();
        }

    }
}

class ClerkTest {
    public static void main(String[] args) {
        Clerk clerk = new Clerk();

        Productor productor1 = new Productor(clerk);
        productor1.setName("生产者1");
        productor1.start();

        Productor productor2 = new Productor(clerk);
        productor2.setName("生产者2");
        productor2.start();
        Consumer consumer1 = new Consumer(clerk);
        consumer1.setName("消费者1");
        consumer1.start();
    }
}