项目截图：

 

实现代码：

1 package exercise2; 2  3 import java.io.BufferedReader; 4 import java.io.IOException; 5 import java.io.InputStreamReader; 6  7 interface CircleShape { 8     double PI = 3.14159; 9 10     double area(double radius);11 }12 13 class Circle implements CircleShape {14     int radius;15 16     public Circle(int r) {17         radius = r;18     }19 20     public double perimeter() {21         return (2 * PI * radius);22     }23 24     @Override25     public double area(double radius) {26         return (PI * radius * radius);27     }28 }29 30 class Cylinder extends Circle implements CircleShape {
   // 子类会继承父类对于接口的实现31     int heigh;32     int radius;33 34     public Cylinder(int r, int h) {35         super(r);36         heigh = h;37     }38 39     public double baseAera(double radius) {40         return area(radius);41     }42 43     public double area1(double radius) {44         return (heigh * super.perimeter() + 2 * area(radius));45     }46 47     public double volume(double radius) {48         return (heigh * area(radius));49     }50 }51 52 public class Ex13_2 {53     public static void main(String[] args) throws IOException {54         int r1, r2;55         String t;56         System.out.println("请输入圆cir1和cir2的半径r1,r2");57         BufferedReader scan = new BufferedReader(new InputStreamReader(58                 System.in));59         t = scan.readLine();60         r1 = Integer.parseInt(t);61         t = scan.readLine();62         r2 = Integer.parseInt(t);63         Circle cir1 = new Circle(r1);64         Circle cir2 = new Circle(r2);65         System.out.println("圆cir1的面积是" + cir1.area(r1) + "\t周长是："66                 + cir1.perimeter());67         System.out.println("圆cir2的面积是" + cir1.area(r2) + "\t周长是："68                 + cir2.perimeter());69         int h1, h2;70         System.out.println("请输入圆柱cy1的半径和高：");71         t = scan.readLine();72         r1 = Integer.parseInt(t);73         t = scan.readLine();74         h1 = Integer.parseInt(t);75         Cylinder cy1 = new Cylinder(r1, h1);76         System.out.println("cy1的底圆面积是：" + cy1.baseAera(r1));77         System.out.println("cy1的体积是：" + cy1.volume(r1) + "\t表面积是："78                 + cy1.area1(r1));79 80         System.out.println("请输入圆柱cy2的半径和高：");81         t = scan.readLine();82         r2 = Integer.parseInt(t);83         t = scan.readLine();84         h2 = Integer.parseInt(t);85         Cylinder cy2 = new Cylinder(r2, h2);86         System.out.println("cy2的底圆面积是：" + cy2.baseAera(r1));87         System.out.println("cy2的体积是：" + cy2.volume(r1) + "\t表面积是："88                 + cy2.area1(r2));89     }90 91 }