Java 接口在开发中的作用

public class Test{
    public static void main(String[] arg) {
        Animal cat = new Cat();
        Animal dog = new Dog();
        Master master = new Master();
        master.feed(cat);
        master.feed(dog);
    }
}

public class Master {
    public void feed(Animal animal){
        animal.eat();
    }
}

public abstract class Animal {
    public abstract void eat();
}

public class Cat extends Animal{

    @Override
    public void eat() {
        System.out.println("小猫正在快乐的吃鱼");
    }
}

public class Dog extends Animal{

    @Override
    public void eat() {
        System.out.println("小狗正在快乐的啃骨头");
    }
}