一)在base包中
编写动物(Animal)接口，定义抽象方法
eat(),sleep()，show（）
定义一个抽象类 哺乳动物 Mammal，实现Animal接口（但是暂不实现它的三个抽象方法），在这个抽象类中增加milk吃奶的抽象方法
定义一个抽象类 爬行动物 Reptile ，实现Animal接口（但是暂不实现它的三个抽象方法），在这个抽象类中增加crawl 爬行的抽象方法。
(二)在utility包中
定义 Person，Monkey，Cat，Dog，继承Mammal，实现其所有方法，每个类中定义两个属性，提供两个构造函数，提供打印输出的方法show()，输出动物的属性;
定义 Snake,Crocodile,继承Reptile，实现其所有方法，每个类中定义两个属性，提供两个构造函数。提供打印输出的方法show()，输出动物的属性。
(三)在javastudy包中，定义一个类Test1，
定义一个长度为6的Animal数组，分别存放以上的每一种动物，循环取出每个动物，调用其方法。要求所有方法都要被调用到【eat,sleep,show,milk,crawl】,其中要用到instanceof，把代码写到精简。
代码：
//Animal.java
package base;
public interface Animal {
public abstract void eat();
public abstract void sleep();
public abstract void show();
}
//Mammal.java
package base;
public abstract class Mammal implements Animal{
public abstract void milk();
}
//Reptile.java
package base;
public abstract class Reptile implements Animal {
public abstract void crawl();
}
//Cat.java
package utility;
import base.Mammal;
public class Cat extends Mammal {
private String species;
private String keyLink;
public Cat(){
species="Cat";
keyLink="Mammal";
}
public Cat(String species,String keyLink){
this.species=species;
this.keyLink=keyLink;
}
public void eat(){System.out.println(species+" is eating.");}
public void sleep(){System.out.println(species+" is sleeping.");}
public void milk(){System.out.println(species+" is drinking milk.");}
public void show(){
System.out.println("species:"+species);
System.out.println("key link:"+keyLink);
}
}
//Dog.java
package utility;
import base.Mammal;
public class Dog extends Mammal {
private String species;
private String keyLink;
public Dog(){
species="Dog";
keyLink="Mammal";
}
public Dog(String species,String keyLink){
this.species=species;
this.keyLink=keyLink;
}
public void eat(){System.out.println(species+" is eating.");}
public void sleep(){System.out.println(species+" is sleeping.");}
public void milk(){System.out.println(species+" is drinking milk.");}
public void show(){
System.out.println("species:"+species);
System.out.println("key link:"+keyLink);
}
}
//Monkey.java
package utility;
import base.Mammal;
public class Monkey extends Mammal {
private String species;
private String keyLink;
public Monkey(){
species="Monkey";
keyLink="Mammal";
}
public Monkey(String species,String keyLink){
this.species=species;
this.keyLink=keyLink;
}
public void eat(){System.out.println(species+" is eating.");}
public void sleep(){System.out.println(species+" is sleeping.");}
public void milk(){System.out.println(species+" is drinking milk.");}
public void show(){
System.out.println("species:"+species);
System.out.println("key link:"+keyLink);
}
}
//Person.java
package utility;
import base.Mammal;
public class Person extends Mammal {
private String species;
private String keyLink;
public Person(){
species="Person";
keyLink="Mammal";
}
public Person(String species,String keyLink){
this.species=species;
this.keyLink=keyLink;
}
public void eat(){System.out.println(species+" is eating.");}
public void sleep(){System.out.println(species+" is sleeping.");}
public void milk(){System.out.println(species+" is drinking milk.");}
public void show(){
System.out.println("species:"+species);
System.out.println("key link:"+keyLink);
}
}
//Crocodile.java
package utility;
import base.Reptile;
public class Crocodile extends Reptile {
private String species;
private String keyLink;
public Crocodile(){
species="Crocodile";
keyLink="Reptile";
}
public Crocodile(String species,String keyLink){
this.species=species;
this.keyLink=keyLink;
}
public void eat(){System.out.println(species+" is eating.");}
public void sleep(){System.out.println(species+" is sleeping.");}
public void crawl(){System.out.println(species+" is crawling.");}
public void show(){
System.out.println("species:"+species);
System.out.println("key link:"+keyLink);
}
}
//Snake.java
package utility;
import base.Reptile;
public class Snake extends Reptile {
private String species;
private String keyLink;
public Snake(){
species="Snake";
keyLink="Reptile";
}
public Snake(String species,String keyLink){
this.species=species;
this.keyLink=keyLink;
}
public void eat(){System.out.println(species+" is eating.");}
public void sleep(){System.out.println(species+" is sleeping.");}
public void crawl(){System.out.println(species+" is crawling.");}
public void show(){
System.out.println("species:"+species);
System.out.println("key link:"+keyLink);
}
}
//Test1.java
package javastudy;
import base.*;
import utility.*;
public class Test1 {
public static void main(String args[]){
Animal[] animal=new Animal[]{new Cat(),new Crocodile(),new Dog(),new Monkey(),new Person(),new Snake()};
for(Animal i:animal){
i.eat();
i.sleep();
if(i instanceof Mammal){
Mammal m=(Mammal)i;
m.milk();
}
else if(i instanceof Reptile){
Reptile r=(Reptile)i;
r.crawl();
}
else {System.err.println("error!");}
i.show();
System.out.println("--------------");
}
}
}
运行结果：
Cat is eating.
Cat is sleeping.
Cat is drinking milk.
species:Cat
key link:Mammal
--------------
Crocodile is eating.
Crocodile is sleeping.
Crocodile is crawling.
species:Crocodile
key link:Reptile
--------------
Dog is eating.
Dog is sleeping.
Dog is drinking milk.
species:Dog
key link:Mammal
--------------
Monkey is eating.
Monkey is sleeping.
Monkey is drinking milk.
species:Monkey
key link:Mammal
--------------
Person is eating.
Person is sleeping.
Person is drinking milk.
species:Person
key link:Mammal
--------------
Snake is eating.
Snake is sleeping.
Snake is crawling.
species:Snake
key link:Reptile
--------------好难呀！！！还不会