2019.01.21多态

 1 package pet;
 2 //宠物类---父类
 3 public abstract class Pet {
 4     private int heath;
 5     private String name;
 6     
 7     public Pet(int heath, String name) {
 8         super();
 9         this.heath = heath;
10         this.name = name;
11     }
12     public int getHeath() {
13         return heath;
14     }
15     public void setHeath(int heath) {
16         if(heath<0) {
17             System.out.println("健康值不能为负，默认为60");
18             heath = 60;
19         }
20         this.heath = heath;
21     }
22     public String getName() {
23         return name;
24     }
25     public void setName(String name) {
26         this.name = name;
27     }
28     //自白方法
29     public void show() {
30         System.out.println("宠物的姓名为："+this.getName()+",健康值为："+this.getHeath());
31     }
32     //抽象玩的方法
33     public abstract void play();
34     //抽象吃的方法
35     public abstract void eat();
36 }

 1 package pet;
 2 //狗类---子类
 3 public class Dog extends Pet{
 4     public Dog(int heath, String name) {
 5         super(heath,name);
 6     }
 7     //重写父类玩的方法
 8     public void play() {
 9         if(this.getHeath()>0) {
10             System.out.println("狗狗叼飞碟");
11             this.setHeath(this.getHeath()-10);
12             System.out.println("叼玩飞碟后，"+this.getName()+"的健康值为："+this.getHeath());
13         }else if(this.getHeath()<0) {
14             System.out.println("体力耗光了，不能再玩了");
15         }
16     }
17     //重写父类吃的方法
18     public void eat() {
19         if(this.getHeath()<100) {
20             System.out.println("给狗狗吃根骨头");
21             this.setHeath(this.getHeath()+3);
22             System.out.println(this.getName()+"的健康值为："+this.getHeath());
23         }else {
24             System.out.println("狗狗吃饱了");
25         }
26     }
27 }

 1 package pet;
 2 //企鹅类---子类
 3 public class Penguin extends Pet {
 4     public Penguin(int heath, String name) {
 5         super(heath, name);
 6     }
 7     //重写父类玩的方法
 8     public void play() {
 9         if(this.getHeath()>0) {
10             System.out.println("让企鹅游泳");
11             this.setHeath(this.getHeath()-15);
12             System.out.println(this.getName()+"的健康值为"+this.getHeath());
13         }else if(this.getHeath()<0) {
14             System.out.println("体力耗光了，不能再玩了");
15         }
16     }
17     //重写父类吃的方法
18     public void eat() {
19         if(this.getHeath()<100) {
20             System.out.println("给企鹅吃条鱼");
21             this.setHeath(this.getHeath()+5);
22             System.out.println(this.getName()+"的健康值为："+this.getHeath());
23         }else {
24             System.out.println("企鹅吃饱了");
25         }
26     }
27 }

 1 package pet;
 2 //主人类
 3 public class Master {
 4     public void play(Pet pet) {
 5         //判断给的宠物是否为狗类
 6         if(pet instanceof Dog) {
 7         //向下转型，将pet由原来的宠物类强转为狗类
 8             Dog d = (Dog)pet;
 9             d.eat();
10             d.play();
11         }else{
12             Penguin p = (Penguin)pet;
13             p.eat();
14             p.play();
15         }
16     }
17 }

 1 package pet;
 2 //测试类
 3 public class Test {
 4     public static void main(String[] args) {
 5         //父类类型引用子类对象
 6         Pet d = new Dog(70, "布拉多犬");
 7         d.show();
 8         Master ms1 = new Master();
 9         System.out.println("狗狗的健康值为："+d.getHeath());
10         ms1.play(d);
11         System.out.println("***********************************");
12         Pet p = new Penguin(85,"Q妹");
13         p.show();
14         Master ms2 = new Master();
15         System.out.println("企鹅的健康值为:"+p.getHeath());
16         ms2.play(p);
17     }        
18 }