需求

编写一个程序，Master类中有一个feed（喂食）方法，可以完成主任给动物喂食物的信息。

Animal

package test;
public class Animal {
    private String name;
    public Animal(String name) {
        this.name = name;
    }
    public String getName() {
        return name;
    }
    public void setName(String name) {
        this.name = name;
    }
}

Cat

package test;
public class Cat extends Animal {
    public Cat(String name) {
        super(name);
    }
}

Dog

package test;
public class Dog extends Animal {
    public Dog(String name) {
        super(name);
    }
}

Pig

package test;
public class Pig extends Animal {
    public Pig(String name) {
        super(name);
    }
}

Food

package test;
public class Food {
    private String name;
    public Food(String name) {
        this.name = name;
    }
    public String getName() {
        return name;
    }
    public void setName(String name) {
        this.name = name;
    }
}

Fish

package test;
public class Fish extends Food {
    public Fish(String name) {
        super(name);
    }
}

Bone

package test;
public class Bone extends Food {
    public Bone(String name) {
        super(name);
    }
}

Rice

package test;
public class Rice extends Food {
    public Rice(String name) {
        super(name);
    }
}

Master

package test;
public class Master {
    private String name;
    public Master(String name) {
        this.name = name;
    }
    public String getName() {
        return name;
    }
    public void setName(String name) {
        this.name = name;
    }
    //使用多态机制，可以统一的管理主人喂食的问题
    //animal 编译类型是Animal,可以指向(接收) Animal子类的对象
    //food 编译类型是Food ,可以指向(接收) Food子类的对象
    public void feed(Animal animal, Food food) {
        System.out.println("主人 " + name + " 给 " + animal.getName() + " 吃 " + food.getName());
    }
    //传统方法
    /*//主人给小狗 喂食 骨头
    public void feed(Dog dog, Bone bone) {
        System.out.println("主人 " + name + " 给 " + dog.getName() + " 吃 " + bone.getName());
    }
    //主人给 小猫喂 鱼
    public void feed(Cat cat, Fish fish) {//构成了方法的重载
        System.out.println("主人 " + name + " 给 " + cat.getName() + " 吃 " + fish.getName());
    }*/
    //问题引出：
    //如果动物很多，食物很多
    //===> feed 方法很多，不利于管理和维护
}

Main

package test;
public class Main {
    public static void main(String[] args) {
        Master tom = new Master("汤姆");
        Dog dog = new Dog("大黄~");
        Bone bone = new Bone("大棒骨~");
        tom.feed(dog, bone);
        Cat cat = new Cat("小花猫~");
        Fish fish = new Fish("黄花鱼~");
        System.out.println("===========-------");
        tom.feed(cat, fish);
        //添加 给小猪吃米饭
        Pig pig = new Pig("小花猪");
        Rice rice = new Rice("米饭");
        System.out.println("===================");
        tom.feed(pig, rice);
    }
}

运行结果