创建一个Java project，项目名为Pet。用以实现给宠物喂食物的功能。 2. 按照如下要求创建一组类： src |--com |--pet |--animal |--Dog.java |--food |--Food.java |--Meat.java |--Bone.java |--MainApp.java 3. Meat和Bone继承Food类，他们都覆写了Food类中needMoney()函数，用以返回费用值。Meat为30元；Bone为15元。 4. 在Dog类中实现一个方法：int eat(Food food, int money)，money为原有的钱，给每次调用，根据食物价格进行扣款，返回剩余的钱。 5. 在MainApp类中创建一个main函数，用于给宠物喂食物。设计一周的菜谱（一天一种食物），以及总的费用200元。 打印输出每天宠物吃的食物，以及资金的结余。用java语言

来完成以上要求的代码如下：

package com.pet;

public abstract class Food {
    public abstract int needMoney();
}

public class Meat extends Food{
    @Override
    public int needMoney() {
        return 30;
    }
}

public class Bone extends Food{
    @Override
    public int needMoney() {
        return 15;
    }
}

package com.pet.animal;
import com.pet.Food;

public class Dog {
    private int money = 200;

    public int eat(Food food, int money){
        int cost = food.needMoney();
        this.money -= cost;
        return this.money;
    }
}

package com.pet;

import com.pet.animal.Dog;
import com.pet.food.Meat;
import com.pet.food.Bone;

public class MainApp {
    public static void main(String[] args){
        Dog dog = new Dog();
        Food[] menu = new Food[]{new Meat(), new Bone(), new Meat(), new Bone(), new Meat(), new Bone(), new Meat()};
        int cost = 0;

        for (int i = 0; i < menu.length; i++){
            System.out.println("Day "+ (i+1) + ": ");

            cost += menu[i].needMoney();
            int leftMoney = dog.eat(menu[i], 200);

            System.out.println("We fed the dog with "+ menu[i].getClass().getSimpleName() +", which costs "+ menu[i].needMoney() + " yuan.");
            System.out.println("We have "+ leftMoney +" yuan left.");

            if (leftMoney < 0){
                System.out.println("The dog will be starving!");
                break;
            }
        }
        System.out.println("We spent "+ cost +" yuan in total for a week.");
    }
}

运行结果如下：

Day 1: 
We fed the dog with Meat, which costs 30 yuan.
We have 170 yuan left.
Day 2: 
We fed the dog with Bone, which costs 15 yuan.
We have 155 yuan left.
Day 3: 
We fed the dog with Meat, which costs 30 yuan.
We have 125 yuan left.
Day 4: 
We fed the dog with Bone, which costs 15 yuan.
We have 110 yuan left.
Day 5: 
We fed the dog with Meat, which costs 30 yuan.
We have 80 yuan left.
Day 6: 
We fed the dog with Bone, which costs 15 yuan.
We have 65 yuan left.
Day 7: 
We fed the dog with Meat, which costs 30 yuan.
We have 35 yuan left.
We spent 165 yuan in total for a week.