JavaSE-11.3.3【接口案例-猫和狗】

package day2.yubaby03.p3;

/*
3.4 接口案例-猫和狗
 */

public class AnimalDemo {

    public static void main(String[] args) {
        Jumpping j = new Cat();
        j.jump();

        Animal a = new Cat();
        a.setName("tom");
        a.setAge(1);
        System.out.println(a.getName() + "," + a.getAge());
        a.eat();
//        a.jump(); //error
        ((Cat) a).jump(); //ok
        //or
        Cat c = (Cat)a;
        c.jump(); //ok

        a = new Cat("sam", 2);
        System.out.println(a.getName() + "," + a.getAge());
        a.eat();
        ((Cat) a).jump();

        //从上述可以看出，通过接口得到的对象只能调用接口的成员方法，通过父类的只能调用父类的
        //更常用的写法：（子类/实现类，既可以调用接口中的方法也可以调用父类中的）
        Cat cat = new Cat();
        cat.setName("it");
        cat.setAge(3);
        System.out.println(cat.getName() + "," + cat.getAge());
        cat.eat();
        cat.jump();
    }

}

　　

package day2.yubaby03.p3;

public abstract class Animal {

    private String name;
    private int age;

    public Animal() {
    }

    public Animal(String name, int age) {
        this.name = name;
        this.age = age;
    }

    public void setName(String name) {
        this.name = name;
    }

    public void setAge(int age) {
        this.age = age;
    }

    public String getName() {
        return name;
    }

    public int getAge() {
        return age;
    }

    public abstract void eat();
}

　　

package day2.yubaby03.p3;

public interface Jumpping {

//    public abstract void jump();

    //或

    void jump();

}

　　

package day2.yubaby03.p3;

public class Cat extends Animal implements Jumpping{

    public Cat() {
    }

    public Cat(String name, int age) {
        super(name, age);
    }

    @Override
    public void eat() { //重写自父类
        System.out.println("猫猫吃饭了");
    }

    @Override
    public void jump() { //重写自接口
        System.out.println("猫猫跳高了");
    }
}

　　

package day2.yubaby03.p3;

public class Dog extends Animal implements Jumpping{

    public Dog() {
    }

    public Dog(String name, int age) {
        super(name, age);
    }

    @Override
    public void eat() {
        System.out.println("狗狗吃饭了");
    }

    @Override
    public void jump() {
        System.out.println("狗狗跳高了");
    }
}