Inheritence : Overloading and Overiding (Shape Problem Solving) in Java

 

Based on figure, Write a java program to define  superclasses and subclasses with suitable attributes and method to compute areas of circle, rectangle and triangle. As for cone and cylinder compute the surface are and its volume. Create TestApplication class that contains main () method to test functionalities of classes that you have created.

Shape.java

public abstract class Shape {

    public abstract double area();

    public abstract double perimeter();

}

Rectangle.java

public class Rectangle extends Shape {

    private final double width, length; //sides

 

    public Rectangle() {

        this(1,1);

    }

    public Rectangle(double width, double length) {

        this.width = width;

        this.length = length;

    }

 

    @Override

    public double area() {

        // A = w * l

        return width * length;

    }

 

    @Override

    public double perimeter() {

        // P = 2(w + l)

        return 2 * (width + length);

    }

 

public String toString(){

return ("Rectangle width: " + width + " and length: " + length

                + "\nResulting area: " + area()

                + "\nResulting perimeter: " + perimeter() + "\n");

}

}

Circle.java

public class Circle extends Shape {

    private final double radius;

    final double pi = Math.PI;

 

    public Circle() {

        this(1);

    }  

    public Circle(double radius) {

        this.radius = radius;

    }

 

    @Override

    public double area() {

        // A = π r^2

        return pi * Math.pow(radius, 2);

    }

 

    public double perimeter() {

        // P = 2πr

        return 2 * pi * radius;

    }

 

public String toString(){

return ("Circle radius: " + radius

+ "\nResulting Area: " + area()

+ "\nResulting Perimeter: " + perimeter() + "\n");

}

}

Triangle.java

public class Triangle extends Shape {

    private final double a, b, c; // sides

 

    public Triangle() {

        this(1,1,1);

    }

    public Triangle(double a, double b, double c) {

        this.a = a;

        this.b = b;

        this.c = c;

    }

 

    @Override

    public double area() {

        // Heron's formula:

        // A = SquareRoot(s * (s - a) * (s - b) * (s - c))

        // where s = (a + b + c) / 2, or 1/2 of the perimeter of the triangle

        double s = (a + b + c) / 2;

        return Math.sqrt(s * (s - a) * (s - b) * (s - c));

    }

 

    @Override

    public double perimeter() {

        // P = a + b + c

        return a + b + c;

    }

}

Cylinder.java

public class Cylinder extends Circle {

   // private instance variable

   private final double height;

 

   // Constructors

   public Cylinder() {

      super();  // invoke superclass' constructor Circle()

      this.height=1;

      System.out.println("Constructed a Cylinder with Cylinder()"); 

   }

   public Cylinder(double height) {

      super();  // invoke superclass' constructor Circle()

      this.height = height;

      System.out.println("Constructed a Cylinder with Cylinder(height)"); 

   }

   public Cylinder(double height, double radius) {

      super(radius);  // invoke superclass' constructor Circle(radius)

      this.height = height;

      System.out.println("Constructed a Cylinder with Cylinder(height, radius)"); 

   }

   /** Returns the volume of this Cylinder */

   public double getVolume() {

      return area()*height;   // Use Circle's getArea()

   }

   public String toString() {

      return ("Height: " + height +

 "\nArea of Circle: " + area() + "This is a Cylinder volume:" + getVolume() + "\n"); 

   }

}

Cone.java

public class Cone extends Circle{

private final double height;

 

public Cone() {

      super();  // invoke superclass' constructor Cone()

      this.height=1;

      System.out.println("Constructed a Cone with Cone()"); 

   }

public Cone(double height) {

      super();  // invoke superclass' constructor Cone()

      this.height = height;

      System.out.println("Constructed a Cone with Cone(height)"); 

   }

public Cone(double height, double radius) {

      super(radius);  // invoke superclass' constructor Circle(radius)

      this.height = height;

      System.out.println("Constructed a Cone with Cone(height, radius)"); 

   }

   public double getVolume() {

      return  area()*height/(3*7);   // Use Circle's getArea()

   }

public String toString() {

      return ("Height: " + height +

 "\nArea of Circle: " + area() + "This is a Cone volume:" + getVolume() + "\n"); 

   }

}

TestApplication.java

 

public class TestApplication {

    public static void main(String[] args) {

 

        // Rectangle test

double width = 5, length = 7;

Rectangle rectangle = new Rectangle(width, length);

System.out.println( rectangle.toString());

 

 

        // Circle test

double radius = 5;

Circle circle = new Circle(radius);

System.out.println( circle.toString());

 

        // Triangle test

double a = 5, b = 3, c = 4;

Triangle triangle = new Triangle(a,b,c);

System.out.println("Triangle sides lengths: " + a + ", " + b + ", " + c

+ "\nResulting Area: " + triangle.area()

+ "\nResulting Perimeter: " + triangle.perimeter() + "\n");

  

// Cylinder test

double height = 5;

Cylinder cylinder = new Cylinder(height,radius);

System.out.println( cylinder.toString());

 

// Cone test

 

Cone cone = new Cone(height,radius);

System.out.println( cone.toString());

}

}

Output