JAVA实验，求柱体面积

1、实验名称：求柱体体积
2、实验目的：
理解并使用抽象类及抽象方法
理解并掌握向上转型实现多态
继续掌握引用类型的参数传值的过程及内存中的变化情况
熟练代码调试
实现求圆柱、方柱、三棱柱的体积
3、实验源代码：
Circle.java

public class Circle {
    private  double r;

    public Circle(double r) {
        if(r>0){
            this.r = r;
        }
        else {
            System.out.println("error!");
        }
    }

    public double getArea() {
        return Math.PI * r * r;
    }

    public void setR(double r) {
        if(r>0){
            this.r = r;
        }
        else {
            System.out.println("error!");
        }
    }
}

Square.java

public class square {
    private double a=0;
    private double b=0;
    private double c=0;
    private double h=0;

    public square(double a, double h) {
        this.a = a;
        this.h = h;
    }

    public square(double a, double b, double c) {
        this.a = a;
        this.b = b;
        this.c = c;
    }


    public void setA(double a) {
        if(a>0){
            this.a = a;
        }
        else {
            System.out.println("error!");
        }
    }

    public void setB(double b) {
        if(b>0){
            this.b = b;
        }
        else {
            System.out.println("error!");
        }
    }


    public void setC(double c) {
        if(c>0){
            this.c = c;
        }
        else {
            System.out.println("error!");
        }
    }

    public void setH(double h) {
        if(h>0){
            this.h = h;
        }
        else {
            System.out.println("error!");
        }
    }
    public double getArea(){
        if(h!=0&&b!=0){
            System.out.println("error!");
            return -1;
        }
        if(h!=0){
            double s=a*h/2;
            return s;
        }
        else {
            double p=(a+b+c)/2;
            double s=Math.sqrt(p*(p-a)*(p-b)*(p-c));
            return s;
        }
    }
}

Rectangle.java

public class rectangle {
    private double a;
    private double b;

    public rectangle(double a, double b) {
        if(a>0&&b>0) {
            this.a = a;
            this.b = b;
        }
        else {
            System.out.println("error!");
        }
    }

    public void setA(double a) {
        if(a>0) {
            this.a = a;
        }
        else {
            System.out.println("error!");
        }
    }

    public void setB(double b) {
        if(b>0){
            this.b = b;
        }
        else {
            System.out.println("error!");
        }
    }

    public double getArea() {
        return a*b;
    }
}

Cuboid.java

package 作业.four;

public class cuboid extends rectangle{
    private double h;
    public cuboid(double a, double b,double h) {
        super(a, b);
        if(a>0&&b>0&&h>0) {
            this.h = h;
        }
        else{
            System.out.println("error!");
        }
    }

    public void setR(double h) {
        if(h>0) {
            this.h = h;
        }
        else {
            System.out.println("error!");
        }
    }

    public double getArea() {
        double s=super.getArea();
        return s*h;
    }
}
Cylinder.java
package 作业.four;

public class cylinder extends Circle{
    private double h;
    public cylinder(double r ,double h) {
        super(r);
        if(r>0&&h>0) {
            this.h = h;
        }
        else{
            System.out.println("error!");
        }
    }

    public void setR(double h) {
        if(h>0) {
            this.h = h;
        }
        else {
            System.out.println("error!");
        }
    }

    public double getArea() {
        double s=super.getArea();
        return s*h;
    }
}

Triangular_cylinder.java

public class Triangular_cylinder extends square{
    private double h;
    public Triangular_cylinder(double a, double h1, double h) {
        super(a, h1);
        if(a>0&&h1>0&&h>0) {
            this.h = h;
        }
        else{
            System.out.println("error!");
        }
    }
    public Triangular_cylinder(double a, double b,double c, double h) {
        super(a, b, c);
        if(a>0&&b>0&&h>0) {
            this.h = h;
        }
        else{
            System.out.println("error!");
        }
    }

    public void setR(double h) {
        if(h>0) {
            this.h = h;
        }
        else {
            System.out.println("error!");
        }
    }

    public double getArea() {
        double s=super.getArea();
        return s*h;
    }

}

Demo.java

package 作业.four;

public class Demo {
    public static void main(String[] args) {
        cuboid V1=new cuboid(1,2,3);
        cylinder V2=new cylinder(1,1);
        Triangular_cylinder V3=new Triangular_cylinder(3,4,5,4);
        System.out.println("立方体体积为："+V1.getArea());
        System.out.println("圆柱体体积为："+V2.getArea());
        System.out.println("三角柱体体积为："+V3.getArea());
    }
}

4、实验运行结果图：

5、实验总结：
设计了基础的三个二维图形界面，通过继承的方式去构建三维图像，最后通过Demo主函数进行调用（特殊：设计三角形时，数据进行了两种方式构建）