Java实验六:类的继承和多态

一、实验目的：
掌握类的继承和多态、抽象类及接口基本功能
二、实验内容：
1、设计一个图形类（Graph），设计其子类二维图形和三维图形，二维图形计算面积，三维图形计算体积；设计二维图形的子类圆形、矩形、三角形和梯形，分别计算其面积；设计三维图形的子类圆、长方体，计算其体积

package experiment_six;
import java.util.Scanner;
/*1、设计一个图形类（Graph），
 * 设计其子类二维图形和三维图形，二维图形计算面积，三维图形计算体积；
 * 设计二维图形的子类圆形、矩形、三角形和梯形，分别计算其面积；
 * 设计三维图形的子类圆、长方体，计算其体积
2、模拟动物园饲养员给动物喂食。每一种动物需要吃不同的食物，饲养员针对不同的动物，喂不同的食物。
动物园里有狗（狗吃骨头，会做算术）、猫（猫吃鱼，会跳环）、老虎（老虎吃肉，会顶球）
试采用普通方式、抽象类方式、接口方式来进行多态的实现
*/
	class Graph{
		//static 
		double length;
		//static 
		double width;
		//static 
		double high;
		//static 
		double r;
		//static 
		double top_length;
		//static 
		double bottom_length;
	}
	class TwoGraph extends Graph{
		//int num;
		//float area;
		public /*static*/ void Show(){
			System.out.println("============");
			System.out.println("1.圆形\n2.矩形\n3.三角形\n4.梯形");
		}
		public /*static*/ void Choice(int num){
			@SuppressWarnings("resource")
			Scanner input = new Scanner(System.in);
		if(num==1){
			System.out.println("输入圆半径:");
			r = input.nextDouble();
			System.out.println("圆的面积:"+Circle.Circle_area(r));
			System.out.println("============");
		}
		else if(num==2){
			System.out.println("输入矩形长和宽:");
			length = input.nextDouble();
			width = input.nextDouble();
			System.out.println("矩形的面积:"+JuXing.JuXing_area(length,width));
			System.out.println("============");
		}
		else if(num==3) {
			System.out.println("输入三角形底和高:");
			length = input.nextDouble();
			high = input.nextDouble();
			System.out.println("三角形的面积:"+SanJiao.SanJiao_area(length,high));
			System.out.println("============");
		}
		else if(num==4) {
			System.out.println("输入矩形的上底、下底和高:");
			top_length = input.nextDouble();
			bottom_length = input.nextDouble();
			high = input.nextDouble();
			System.out.println("梯形的面积:"+TiXing.TiXing_area(top_length,bottom_length,high));
			System.out.println("============");
		}
		else
			System.out.println("ERROR");
		}
	}
	class ThreeGraph extends Graph{
		//float size;
		public /*static*/ void Show(){
			System.out.println("============");
			System.out.println("1.球");
			System.out.println("2.长方体");
		}
		public /*static*/ void Choice(int num) {
			@SuppressWarnings("resource")
			Scanner input = new Scanner(System.in);
			if(num==1){
				System.out.println("输入球半径:");
				r = input.nextDouble();
				System.out.println("球的体积:"+Qiu.Qiu_size(r));
				System.out.println("============");
			}
			else if(num==2) {
				System.out.println("输入长方体长宽高:");
				length = input.nextDouble();
				width = input.nextDouble();
				high = input.nextDouble();
				System.out.println("长方体体积:"+FangTi.FangTi_size(length,width,high));
				System.out.println("============");
			}
			else
				System.out.println("ERROR");
		}
	}
	class Circle extends TwoGraph{
		public static double Circle_area(double r){
			return (3.14*r*r);
		}
	}
	class JuXing extends TwoGraph{
		public static double JuXing_area(double length,double width){
			return (length*width);
		}
	}
	class SanJiao extends TwoGraph{
		public static double SanJiao_area(double length,double high){
			return (length*high/2);
		}
	}
	class TiXing extends TwoGraph{
		public static double TiXing_area(double top_length,double bottom_length,double high){
			return ((top_length+bottom_length)*high/2);
		}
	}
	class Qiu extends ThreeGraph{
		public static double Qiu_size(double r){
			return (4*3.14*r*r*r/3);
		}
	}
	class FangTi extends ThreeGraph{
		public static double FangTi_size(double length,double width,double high){
			return (length*width*high);
		}
	}
class experiment_six_one{
	public static void main(String[] args){
		@SuppressWarnings("resource")
		Scanner input = new Scanner(System.in);
		flag:while(true) {
			System.out.println("1.计算面积\n2.计算体积\n0.退出");
			System.out.println("Choice the number:");
			int num = input.nextInt();
			switch(num){
			case 1:TwoGraph twograph = new TwoGraph();
					twograph.Show();
					System.out.println("Choice the number:");
					num = input.nextInt();
					twograph.Choice(num);
			break;
			case 2:ThreeGraph threegraph = new ThreeGraph();
					threegraph.Show();
					System.out.println("Choice the number:");
					num = input.nextInt();
					threegraph.Choice(num);
			break;
			case 0:break flag;//带标签的break
			}
		}
	}
}

2、模拟动物园饲养员给动物喂食。每一种动物需要吃不同的食物，饲养员针对不同的动物，喂不同的食物。
动物园里有狗（狗吃骨头，会做算术）、猫（猫吃鱼，会跳环）、老虎（老虎吃肉，会顶球）
试采用普通方式、抽象类方式、接口方式来进行多态的实现

package experiment_six;

interface Animal { 
    public void eat(Food food);
    public void play();
} 
/** 
*@authorleno 
*一种动物类:狗 
*/ 
class Dog implements Animal { 
    public void eat(Food food) { 
      System.out.print("小狗吃"+food.getName()); 
    }
    public void play() {
    	System.out.println(",会做算术");
    }
} 

/** 
*@authorleno 
*一种动物类:猫 
*/ 
class Cat implements Animal { 
    public void eat(Food food) { 
      System.out.print("小猫吃"+food.getName()); 
    }
    public void play() {
    	System.out.println(",会跳环");
    }
} 

class Tiger implements Animal{
	public void eat(Food food) {
		System.out.print("老虎吃"+food.getName());
	}
    public void play() {
    	System.out.println(",会顶球");
    }
}

/** 
*@authorleno 
*食物抽象类 
*/ 
abstract class Food { 
	 protected String name; 
    public String getName() { 
      return name; 
    } 

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

/** 
*@authorleno 
*一种食物类:骨头 
*/ 
class Bone extends Food {  
    public Bone(String name) { 
      this.name = name; 
    } 
} 

/** 
*@authorleno 
*一种食物类:鱼 
*/ 
class Fish extends Food { 
    public Fish(String name) { 
      this.name = name; 
    } 
} 

class Meat extends Food{
	public Meat(String name) {
		this.name = name;
	}
}


/** 
*@authorleno 
*饲养员类 
* 
*/ 
class Feeder { 
    /** 
    *饲养员给某种动物喂某种食物 
    *@paramanimal 
    *@paramfood 
    */ 
    public void feed(Animal animal,Food food) { 
      animal.eat(food); 
      animal.play();
    } 
} 

/** 
*@authorleno 
*测试饲养员给动物喂食物 
*/ 
public class experiment_six_two { 
    public static void main(String[] args) { 
      Feeder feeder=new Feeder(); 
      Animal animal=new Dog(); 
      Food food=new Bone("骨头"); 
      feeder.feed(animal,food); //给狗喂肉骨头 
      animal=new Cat(); 
      food=new Fish("鱼"); 
      feeder.feed(animal,food); //给猫喂鱼
      animal=new Tiger();
      food=new Meat("肉");
      feeder.feed(animal, food);
    } 
}