JAVA PROGRAMMING LANGUAGE

1. Define the following classes: Rectangle, Circle, Cuboid and Sphere that extend AbstractShape. Each of these should have a static instance variable that represents the number of objects of that kind created. These instance variables should be called: numRectanglesCreated, numCirclesCreated, numCuboidsCreated, and numSpheresCreated. The constructor of each of these classes should increment the appropriate one of these instance variables of the object being created, and it should also increment the parent class static instance variable numShapesCreated. Here is the code for Rectangle class, to use as a model:

public class Rectangle extends AbstractShape

{

private double length;

private double width;

private static int numRectanglesCreated = 0;

public Rectangle(double len, double wid) //constructor

{

length = len;

width = wid;

incrementNumRectanglesCreated();

incrementNumShapesCreated();

}

public double area()

{

double area = length * width;

return area;

}

public double perimeter()

{

double perimeter = 2 * (length + width);

return perimeter;

}

public double volume()

{

return 0.0;

}

private void incrementNumRectanglesCreated()

{

numRectanglesCreated++;

}

private void incrementNumShapesCreated()

{

numShapesCreated++;

}

}

Similarly write the Circle, Cuboid and Sphere classes:

• Circle has a radius (which should be of type double), and two methods called area() and perimeter(). (area = pi* radius * radius; perimeter = 2 * pi * radius; volume is zero) (Note: pi here refers to Math.PI (available in Java))

• Cuboid has length, width and height (all of which should be of type double) and methods area() perimeter() and volume(). Note that area() here means the surface area of the cuboid = 2 * (length * width + width * height + height * length); perimeter is assumed to be always zero and volume is (length * width * height).

• Sphere has a radius (of type double) and has area() and volume() methods. (area = 4.0 * pi * radius * radius; perimeter is zero and volume = (4.0 * pi * radius * radius * radius) / 3.0) (Note: again, pi here refers to Math.PI)

2. Write a ShapeTester class that has only the main method that does the following things:

• Declares an array: AbstractShape[ ] myShapes = new AbstractShape[16];
• Creates 16 Shape objects and fills them in the array: 4 objects of each type using the data given below.

Shape	Length	width	height	radius
Rectangle	10	5	-	-
Rectangle	20	30	-	-
Rectangle	50	10	-	-
Rectangle	-10	-20
Circle	-	-	-	20
Circle	-	-	-	10
Circle	-	-	-	30
Circle	-	-	-	-20
Cuboid	20	10	6	-
Cuboid	40	5	50	-
Cuboid	30	20	20	-
Cuboid	-20	30	-10
Sphere	-	-	-	15
Sphere	-	-	-	25
Sphere	-	-	-	12
Sphere	-	-	-	-10

• In a loop: prints the area, perimeter and volume of each shape. You should ensure that each double value is printed to exactly two decimal places you can use formatted printing (System.out.printf) to do that (or google for some other solution).
• After the loop, it should also print the totals (something like this:

Total number of Rectangle objects = ____

Total number of Circle objects = ____

Total number of Cuboid objects = ____

Total number of Sphere objects = ____

Total number of Shape objects = ____