第9次作业--接口及接口回调

题目:利用接口和接口回调，实现简单工厂模式，当输入不同字符，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。

一.源代码(Shape.java)

package W;
//形状接口
public interface Shape {
    double getArea();
}

二.源代码(Rectangle.java)

package W;
//定义矩形类  创建两个成员变量长和宽
public class Rectangle implements Shape {
    double width;
    double length;
    public Rectangle(double width, double length) {
        this.width = width;
        this.length = length;
    }
    public double getArea() {
        return width * length;
    }
}

三.源代码(Zheng.java)

package W;

public class Zheng extends Rectangle {
    public Zheng(double side) {
        super(side, side);
    }
    public double getArea() {
        return width * width;
    }
}

四.源代码(Triangle.java)

package W;

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(){
        double p=(a+b+c)/2;
        return Math.sqrt(p*(p-a)*(p-b)*(p-c));
    }
}

五.源代码(T.java)

package W;
//梯形类
public class T implements Shape {
    double a;
    double b;
    double height;
    public T(double a,double b,double height){
        this.a=a;
        this.b=b;
        this.height=height;
    }
    public double getArea(){
        return (a+b)*height/2;
    }
}

六.源代码(Circle.java)

package W;
//创建一个圆类
public class Circle implements Shape {
    double radius;
    double PI=3.14;
    public Circle(double radius){
        this.radius=radius;
    }
    public double getArea(){
        
        return PI*radius*radius;
    }
}

七.源代码(Cone.java)

package W;

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;
    }
}

八.源代码(Foctory.java)

package W;
//创建一个工厂类
import java.util.Scanner;

public class Foctory {
    
    Shape getShape(char c) {
            Scanner reader = new Scanner(System.in);
            Shape shape = null;
            switch (c) {
            case 'r':
                System.out.print("请输入矩形的长和宽、柱体的高\n");
                shape = new Rectangle(reader.nextInt(), reader.nextDouble());
                break;
            case 't':
                System.out.print("请输入三角形的三条边,柱体的高\n");
                shape = new Triangle(reader.nextDouble(), reader.nextDouble(), reader.nextDouble());
                break;
            case 'c':
                System.out.print("请输入圆的半径,柱体的高\n");
                shape = new Circle(reader.nextDouble());
                break;
            case 'T':
                System.out.print("请输入梯形的上底下底和高\n");
                shape = new T(reader.nextDouble(), reader.nextDouble(), reader.nextDouble());
                break;
            case 'Z':
                System.out.print("请输入正方形的边长，柱体的高\n");
                shape = new Zheng(reader.nextDouble());
                break;
            }
            return shape;
    }
}

九.源代码(Test.java)

package W;

import java.util.Scanner;

public class Test {
    public static void main(String[] args) {
        while(true){
            Scanner reader = new Scanner(System.in);
            System.out.print("请输入你选择的形状:矩形r,三角形t,圆c,梯形T,正方形Z");
            char c = reader.next().charAt(0);
            Foctory f = new Foctory();
            Cone cone = new Cone(f.getShape(c), reader.nextDouble());
            System.out.print(cone.getVolume());
        }
    }
}

十.成功截图