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。
一、源代码
1、Shape.java
package cn.edu.ccut.jia; public interface Shape { //定义形状接口 abstract double getArea(); }2、Rectangle.java
package cn.edu.ccut.jia; //定义矩形类，创建长、宽两个成员变量，定义求面积方法 public class Rectangle implements Shape{ double length; double width; public Rectangle(double length,double width){ this.length=length; this.width=width; } public double getArea(){ return length*width; } }3、Zheng.java
package cn.edu.ccut.jia; //定义一个正方形类，并继承矩形类 public class Zheng extends Rectangle{ Zheng(double side){ super(side,side);//super调用父类方法 } public double getArea(){//面积方法重写 return length*length; } }4、Yuan.java
package cn.edu.ccut.jia; //定义一个圆类，创建成员变量r，定义求面积方法 public class Yuan implements Shape { double r; double PI=3.14; public Yuan(double r){ this.r=r; } public double getArea(){ return r*r*PI; } }5、Tringle.java
package cn.edu.ccut.jia; //定义一个三角形类，创建三个成员变量w,x,y，定义求面积方法 public class Tringle implements Shape{ double w; double x; double y; public Tringle(double w,double x,double y){ this.w=w; this.x=x; this.y=y; } public double getArea(){ double q=(w+x+y)/2; return Math.sqrt(q*(q-w)*(q-x)*(q-y)); } }6、Tixing.java
package cn.edu.ccut.jia; //定义一个梯形类，创建三个成员变量a,b,h，定义求面积方法 public class Tixing implements Shape{ double a; double b; double h; public Tixing(double a,double b,double h){ this.a=a; this.b=b; this.h=h; } public double getArea(){ return (a+b)*h/2; } }7、Cone.java
package cn.edu.ccut.jia; //定义一个柱体类，创建一个成员变量high和接口对象，定义求体积方法 public class Cone { double high; Shape shape; public Cone(Shape shape,double high){ this.shape=shape; this.high=high; } double getV(){ return high* shape.getArea(); } }8、Foctory.java
package cn.edu.ccut.jia; //创建工厂类 import java.util.*; public class Foctory { Scanner reader=new Scanner(System.in); Shape getShape(char d){ Shape shape=null; switch(d){ case 'r': System.out.println("请输入矩形的长、宽和柱体的高"); shape=new Rectangle(reader.nextDouble(),reader.nextDouble()); break; case 'z': System.out.println("请输入正方形的边长和柱体的高"); shape=new Zheng (reader.nextDouble()); break; case 'y': System.out.println("请输入圆的半径和柱体的高"); shape=new Yuan(reader.nextDouble()); break; case's': System.out.println("请输入三角形的边长和柱体的高"); shape=new Tringle(reader.nextDouble(),reader.nextDouble(),reader.nextDouble()); break; case 't': System.out.println("请输入梯形的上底、下底、高和柱体的高"); shape=new Tixing(reader.nextDouble(),reader.nextDouble(),reader.nextDouble()); break; } return shape; } }9、Test.java
package cn.edu.ccut.jia; import cn.edu.ccut.jia.*; import java.util.*; public class Test { public static void main(String[] args){ while(true){ Scanner reader=new Scanner(System.in); System.out.println("请输入您要选择的形状：矩形r,正方形z,三角形s,圆y,梯形t"); char d=reader.next().charAt(0); Foctory f=new Foctory(); Cone c=new Cone(f.getShape(d),reader.nextDouble()); System.out.println(c.getV()); } } }二、运行截图
转载于:https://www.cnblogs.com/jwwy/p/11612153.html
