一个理解多态的经典例子

/*多态的应用,构建父类的变量，指向子类的对象
 * */
 package com.guang;

public class Duotai {

	/**
	 * @param master
	 */
	public static void main(String[] args) {
		/*
		 * Animal an=new Cat(); an.cry(); an=new Dog(); an.cry();
		 */
		Master master = new Master();
		master.feed(new Dog(), new Bone());


	}

}

class Master {
	public void feed(Animal an, Food f) {
		an.eat();
		f.showname();
	}
}

class Food {
	String name;

	public void showname() {
		System.out.println();
	}
}

class Fish extends Food {
	public void showname() {
		System.out.println("给你鱼");
	}
}

class Bone extends Food {
	public void showname() {
		System.out.println("给你骨头");
	}
}

class Animal {
	String name;

	public void eat() {
		System.out.println("不知道吃什么");
	}

	public String getName() {
		return name;
	}

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

	public int getAge() {
		return age;
	}

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

	int age;

	public void cry() {
		System.out.println("不知道怎么叫");
	}

}

class Cat extends Animal {
	public void cry() {
		System.out.println("猫猫叫");
	}

	public void eat() {
		System.out.println("猫爱吃鱼");
	}
}

class Dog extends Animal {
	public void cry() {
		System.out.println("汪汪叫");
	}

	public void eat() {
		System.out.println("狗爱吃骨头");
	}
}

评论

1 楼 弯之虎 2011-11-13  

恩