Java计算以三角形，矩形，圆形为底的柱形的体积

Java计算以三角形，矩形，圆形为底的柱形的体积

代码如下：
Geometry.java：

public abstract class Geometry {public abstract double getArea();
}

Circle.java：

public class Circle extends Geometry{double i;Circle(double i){this.i=i;}public double getArea() {return 3.14*i*i;}}

Rectangle.java：

public class Rectangle extends Geometry{double i,j;Rectangle(double i,double j){this.i=i;this.j=j;}public double getArea() {return i*j;}}

Triangle.java：

public  class Triangle extends Geometry{double i,j;Triangle(double i,double j){this.i=i;this.j=j;}public double getArea() {return i*j/2;}
}

Pillar.java：

public class Pillar {Geometry bottom;double height;Pillar(Geometry bottom,double height){this.bottom=bottom;this.height=height;}public double getVolume() {if(bottom==null) {System.out.println("没有底，无法计算体积");return -1;}return bottom.getArea()*height;}
}

text.java：

public class text {public static void main(String[] args) {Pillar pillar;Geometry bottom=null;pillar=new Pillar(bottom,100);System.out.println(pillar.getVolume());bottom=new Circle(3);pillar=new Pillar(bottom,100);System.out.println(pillar.getVolume());bottom=new Rectangle(3,4);pillar=new Pillar(bottom,100);System.out.println(pillar.getVolume());bottom=new Triangle(3,4);pillar=new Pillar(bottom,100);System.out.println(pillar.getVolume());}
}

运行结果：