第9次作业--接口及接口回调

一、题目

利用接口和接口回调，实现简单工厂模式，当输入不同的字符，代表相应图形时，利用工厂类获得图形对象，再计算以该图形为底的柱体体积。

 二、源代码

 Juxing.java

/*
创建Juxing类，实现接口Shape
创建成员变量宽width,长length
创建求矩形面积方法
*/


package com;

public class Juxing implements Shape {
    double width;
    double length;

    public Juxing(double width, double length) {
        this.width = width;
        this.length = length;

    }

    public double getArea() {                         //创建求矩形面积的方法
        return width * length;
    }

}

Zheng.java

/*
创建Zheng类，继承Juxing类
创建成员变量边长side
求正方形面积
*/

package com;

public class Zheng extends Juxing {
    public Zheng(double side) {
        super(side, side);
    }

    public Zheng() {
        super(0, 0);
    }

    public double getArea() {                        //创建求正方形面积方法
        return width * width;
    }

}

Triangle.java

/*创建Triangle类，实现Shape接口
求三角形面积
*/

package com;

public class Triangle implements Shape {
    double a;
    double b;
    double c;

    public Triangle(double a, double b, double c) {
        this.a = a;
        this.b = b;
        this.c = c;

    }

    public double getArea() {                                     //创建求三角形面积方法
        double p = (a + b + c) / 2;
        return Math.sqrt(p * (p - a) * (p - b) * (p - c));         
    }

}

Tixing.java

/*
创建Tixing类
求梯形面积
*/

package com;

public class Tixing implements Shape {
    double s;
    double x;
    double h;

    public Tixing(double s, double x, double h) {
        this.s = s;
        this.x = x;
        this.h = h;

    }

    public double getArea() {                //创建求梯形面积的方法
        return (s + x) * h / 2;
    }

}

Yuan.java

/*
创建Yuan类
求圆的面积
*/

package com;

public class Yuan implements Shape {
    double r;
    double PI = 3.14;

    public Yuan(double r, double PI) {
        this.r = r;
    }

    public double getArea() {               //创建求圆面积的方法
        return PI * r * r;

    }

}

Shape.java

/*
定义接口Shape
*/

package com;

public interface Shape {
    double getArea();

}

Cone.java

/*创建柱体类
创建Shape对象、柱体高
创建求体积方法
创建换底方法
*/

package com;

public class Cone {
    Shape shape;
    double high;

    public Cone(Shape shape, double high) {
        this.shape = shape;
        this.high = high;
    }

    public double getVolume() {
        return shape.getArea() * high;        // 接口回调
    }

    public void setRect(Shape shape) {        //换底
        this.shape = shape;
    }

}

Factory.java

/*创建工厂类
创建方法t
创建输入不同字符代表不同图形类的对象
输入以该图形为底的高
返回Shape
*/


package com;
import java.util.*;
public class Factory {

     static Shape shape = null;

    public static Shape k(char c) {
        switch (c) {
        case 'J':
            System.out.println("输入矩形为底的柱体高：");
            shape = new Juxing(4, 5);
            break;
        case 'Z':
            System.out.println("输入正方形为底的柱体高：");
            shape = new Zheng(5);
            break;
        case 'T':
            System.out.println("输入三角形为底的柱体高：");
            shape = new Triangle(4, 5, 6);
            break;
        case 'C':
            System.out.println("输入圆形为底的柱体高：");
            shape = new Yuan(5, 3.14);
            break;
        case 'X':
            System.out.println("输入梯形为底的柱体高：");
            shape = new Tixing(4, 5, 7);
            break;

        }
        return shape;

    }
}

Text.java

/*
创建主方法
插入循环，创建对象，选择不同图形
调用方法求柱体体积
*/


package com;

import java.util.Scanner;
import com.Cone;
import com.Factory;

public class Text {

    public static void main(String[] args) {

        while (true) {
            Scanner reader = new Scanner(System.in);

            System.out.println("请输入图形字母:");
            char c = reader.next().charAt(0);

            Factory factory = new Factory();
            Cone cone = new Cone(factory.k(c), reader.nextDouble());

            System.out.println("输出体积为：" + cone.getVolume());
        }
    }

}

三、运行结果