public class Storage {

    private int storage = 10;
    private int MAX = 10;

    public int getMaxSize() {
        return this.MAX;
    }

    public int getStorage() {
        return this.storage;
    }

    public synchronized void add() {
        if (storage >= MAX) {
            try {
                this
 
.wait();
            } catch (Exception e) {
                e.printStackTrace();
            }
            System.out.println("倉庫已滿,停止存放!");
            return;
        }
        storage += 1;
        System.out.println("倉庫容量+1,目前容量: " + storage);
        notifyAll();
    }

    public synchronized void
 
 del() {
        if (storage <= 0) {
            try {
                this.wait();
            } catch (Exception e) {
                e.printStackTrace();
            }
            System.out.println("倉庫已空,停止取貨!");
            return;
        }
        storage -= 1;
        System.out.println("倉庫容量-1,目前容量: "
 
 + storage);
        notifyAll();
    }

    public static void main(String[] args) {
        Storage storage = new Storage();
        Producer producer = new Producer(storage);
        Consumer consumer = new Consumer(storage);

        Thread p1 = new Thread(producer);
        Thread p2 = new Thread(producer);

        Thread c1 = new Thread(consumer);
        Thread c2 = new Thread(consumer);

        p1.start();
        p2.start();
        c1.start();
        c2.start();
    }

}

class Producer implements Runnable {
    Storage storage;

    public Producer(Storage storage) {
        this.storage = storage;
    }
    @Override
    public void run() {
        while(true) {
            storage.add();
        }
    }
}

class Consumer implements Runnable {
    Storage storage;

    public Consumer(Storage storage) {
        this.storage = storage;
    }

    @Override
    public void run() {
        while(true) {
            storage.del();
        }
    }
}