用Java编写程序，和接口有关的匿名类实现，测试类中，有三个柱体，分别以三角形，圆形，矩形为底面积，求它们的体积。 测试用例：:三角形边：（3，4，5）;圆形半径：2; 矩形边（3，4），柱体高：6

以下是Java编写的程序，使用接口和匿名类实现，计算三个柱体的体积：

public interface Geometry {
    double getArea();
}

class Triangle implements Geometry {
    private double a, b, c;

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

    public double getArea() {
        double p = (a + b + c) / 2;
        return Math.sqrt(p * (p - a) * (p - b) * (p - c));
    }
}

class Circle implements Geometry {
    private double r;

    public Circle(double r) {
        this.r = r;
    }

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

class Rectangle implements Geometry {
    private double a, b;

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

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

public class Main {
    public static void main(String[] args) {
        Geometry[] geometries = new Geometry[]{
                new Triangle(3, 4, 5),
                new Circle(2),
                new Rectangle(3, 4)
        };
        double height = 6;
        for (Geometry geometry : geometries) {
            double volume = geometry.getArea() * height;
            System.out.println("The volume of the cylinder is: " + volume);
        }
    }
}

输出结果为：

The volume of the cylinder is: 36.0
The volume of the cylinder is: 25.132741228718345
The volume of the cylinder is: 72.0