http://www.verejava.com/?id=16992848300456
/**
题目: (孩子,学生) 吃 水果(苹果,葡萄,芒果,菠萝)
思路：
1. 抽象出类 : {孩子(Baby),学生(Student)}, 水果(Fruit){苹果(Apple),葡萄(Grape),芒果(Mango)}
2. 找出类的关系:
水果 -> (孩子,学生)
(苹果,葡萄,芒果) 是 水果的分类
3. 找出属性: 孩子,学生(姓名,水果引用)
4. 找出方法: 孩子,学生都吃(eat)水果
子类->父类的转换 作用 ：解耦 也就是降低类与类之间的耦合度 提供可扩展性
*/
public class Polymorphism4 {
public static void main(String[] args) {
//实例化一个Baby
Baby baby = new Baby("李明");
//实例化一个学生
Student stu = new Student("张涛");
//实例化一个苹果 和 一个葡萄
Apple apple = new Apple("红富士");
Grape grape = new Grape("黑葡萄");
Mango mango = new Mango("大芒果");
PineApple pineApple = new PineApple("菠萝");
//李明吃水果
baby.eat(apple);
System.out.println(baby.getName() + " 吃了 " + baby.getFruit().getName());
baby.eat(grape);
System.out.println(baby.getName() + " 吃了 " + baby.getFruit().getName());
baby.eat(mango);
System.out.println(baby.getName() + " 吃了 " + baby.getFruit().getName());
baby.eat(pineApple);
System.out.println(baby.getName() + " 吃了 " + baby.getFruit().getName());
//张涛吃水果
stu.eat(apple);
System.out.println(stu.getName() + " 吃了 " + stu.getFruit().getName());
stu.eat(grape);
System.out.println(stu.getName() + " 吃了 " + stu.getFruit().getName());
stu.eat(mango);
System.out.println(stu.getName() + " 吃了 " + stu.getFruit().getName());
stu.eat(pineApple);
System.out.println(stu.getName() + " 吃了 " + stu.getFruit().getName());
}
}
class Baby {
private Fruit fruit;
private String name;
public Baby(String name) {
this.name = name;
}
public String getName() {
return this.name;
}
public Fruit getFruit() {
return this.fruit;
}
//吃水果
public void eat(Fruit fruit) {
this.fruit = fruit;
}
}
class Student {
private Fruit fruit;
private String name;
public Student(String name) {
this.name = name;
}
public String getName() {
return this.name;
}
public Fruit getFruit() {
return this.fruit;
}
//吃水果
public void eat(Fruit fruit) {
this.fruit = fruit;
}
}
class Fruit {
private String name;
public Fruit(String name) {
this.name = name;
}
public String getName() {
return this.name;
}
}
class PineApple extends Fruit {
public PineApple(String name) {
super(name);
}
}
class Apple extends Fruit {
public Apple(String name) {
super(name);
}
}
class Grape extends Fruit {
public Grape(String name) {
super(name);
}
}
class Mango extends Fruit {
public Mango(String name) {
super(name);
}
}
