package 多态.典型用法;/** 宠物 父类* */public  abstract class Pet {    private int health;//健康    public int getHealth() {        return health;    }    public void setHealth(int health) {        this.health = health;    }    //宠儿生病去医院    public  abstract void toHopsoital();    public  abstract void eat();}

package 多态.典型用法;/** 狗类* */public class Dog extends Pet {    @Override    public void toHopsoital() {            System.out.println("打针");            System.out.println("吃药");            //狗的治疗健康度+3            int old = this.getHealth();            this.setHealth(old+3);        }     public void jiefeipan(){         System.out.println("接飞盘");     }    @Override    public void eat() {        System.out.println("狗吃屎");        int old = this.getHealth();        this.setHealth(old+30);    }}

package 多态.典型用法;/** 企鹅* */public class Penguin extends Pet {    @Override    public void toHopsoital() {//        System.out.println("打针");            System.out.println("吃药");            //企鹅的治疗健康度+5            int old = this.getHealth();            this.setHealth(old+5);    }    public void qianshui(){        System.out.println("潜水");    }    @Override    public void eat() {        System.out.println("企鹅吃毛线");        int old = this.getHealth();        this.setHealth(old+50);    }}

package 多态.典型用法;/** snake类* */public  class  Snake extends Pet {    @Override    public void toHopsoital() {        System.out.println("打针");        System.out.println("吃药");        //狗的治疗健康度+3        int old = this.getHealth();        this.setHealth(old+6);    }    @Override    public void eat() {        System.out.println("你就啥都吃不到" );        int old = this.getHealth();        this.setHealth(old+60);    }}

package 多态.典型用法;/* *对象 instanceof 类或接口 * 判断对象是否是该类的对象，如果是返回true,不是返回false * * */public class Master {    //    void cure(Pet pet) {  //赋值是父类 传参传的类型是子类对象   相当于Pet pet=dog  Pet是父类 dog是子类        pet.toHopsoital();        //想调用子类独有的方法        //如果传进来的类型        if (pet instanceof Dog) {            ((Dog) pet).jiefeipan();        } else if (pet instanceof Penguin) {            ((Penguin) pet).qianshui();        }    }    void eat(Pet pet){        pet.eat();    }}

package 多态.典型用法;/** 不用多态 增加一种宠物类** */public class Test {    public static void main(String[] args) {        Master master = new Master();//        Dog dog =new Dog();        dog.setHealth(22);        master.cure(dog); // Pet pet=dog        System.out.println("治疗后健康度是"+dog.getHealth());        Penguin penguin =new Penguin();        penguin.setHealth(19);        master.cure(penguin);        System.out.println("治疗后健康度是"+penguin.getHealth());        Snake snake =new Snake();        snake.setHealth(19);        master.cure(snake);        System.out.println("治疗后健康度是"+snake.getHealth());        master.eat(dog);        System.out.println("健康度是"+dog.getHealth());        master.eat(penguin);        System.out.println("健康度是"+penguin.getHealth());        master.eat(snake);        System.out.println("健康度是"+snake.getHealth());    }    }