第9次作业--接口及接口回调

package Test2;
  2 import java.util.Scanner;
  3 
  4 interface Shape{//图形类
  5     double getArea();
  6 }
  7 
  8 class Rectangle implements Shape {//长方形类
  9     double width;
 10     double length;
 11     
 12     public Rectangle(double width,double length) {
 13         this.width = width;
 14         this.length = length;
 15     }
 16 
 17     @Override
 18     public double getArea() {
 19         // TODO Auto-generated method stub
 20         return width*length;
 21     }
 22 }
 23 
 24 class Square2 extends Rectangle{//正方形类
 25     
 26     public Square2(double width) {
 27         super(width, width);
 28         // TODO Auto-generated constructor stub
 29     }
 30     public double getArea() {
 31         return width* width;
 32     }
 33 }
 34 
 35 class Triangle implements Shape{//三角形类
 36     double length1;
 37     double length2;
 38     double length3;
 39     public Triangle(double length1,double length2,double length3) {
 40         this.length1 = length1;
 41         this.length2 = length2;
 42         this.length3 = length3;
 43     }
 44     public double getArea() {
 45         double num = (length1+length2+length3)/2;
 46         return Math.sqrt(num*(num-length1)*(num-length2)*(num-length3));
 47     }
 48 }
 49 
 50 class Prism {
 51     Shape shape;
 52     double hight;
 53     public Prism(Shape shape,double hight) {//棱柱类
 54         this.hight = hight;
 55         this.shape = shape;
 56     }
 57     public double getVolumn() {
 58         return shape.getArea()*hight;
 59     }
 60     public void setShape(Shape shape) {
 61         this.shape = shape;
 62     }
 63 }
 64 
 65 class Circle implements Shape{//圆类
 66     double r;
 67     final double PI=3.14;
 68     Circle(double r){
 69         this.r=r;
 70     }
 71     public double getArea(){
 72         return PI*r*r;
 73     }
 74 }
 75 
 76 class Factory{//工厂类
 77      Shape shape;
 78      char gc;
 79      Factory(char ch){
 80          this.gc = ch;
 81      }
 82      public Shape getShape(){
 83          switch(gc){
 84          case 't':shape=new Triangle(1,2,3);break;
 85          case 'r':shape=new Rectangle(4,5);break;
 86          case 's':shape=new Square2(6);break;
 87          case 'c':shape=new Circle(7);break;
 88          }
 89          return shape;
 90      }
 91      public char getgc(){
 92          return gc;
 93          }
 94      public void setShape(Shape shape){
 95          this.shape=shape;
 96          }
 97      public void setCh(char ch){
 98          this.gc=ch;
 99      }
100 }
101 
102 public class tt {//主函数
103 
104     public static void main(String[] args) {
105         for(int i = 0;i<4;i++) {
106             Scanner sc = new Scanner(System.in);
107             String str = sc.next();
108             char ch = str.charAt(0);
109             Factory fa=new Factory(ch);
110             Prism pri=new Prism(fa.getShape(),6);
111             pri.setShape(fa.getShape());
112             double vol=pri.getVolumn();
113             System.out.println(vol);
114         }
115         
116     }
117 }