a$)$ Create a class Book with the following instance variables:

o Title: string

o Author: string

o Number Of Pages: int

o Static variable to track the total number of books created.

$1.$ Include both default and arguments constructors.

$2.$ Implement getters and setters for all instance variables.

$3.$ Implement a method displayInfo$()$ to display book details and a static method getTotalBooks$()$ to show the total number of books.

$4.$ In the main$()$ method, create book objects and display their information.

$5.$ Modify some details using setters.

b$)$ Create a subclass Ebook that inherits from Book that has the following:

$1.$ A new instance variable as file Size then

$2.$ Override$/$overload the displayInfo$()$ method in Ebook to display the file size in addition.

$3.$ Use an array of Book type, storing both Book and Ebook objects.

$4.$ Handle invalid data $($e$.$g$.,$ negative file size$)$ by throwing a custom exception.

Sample Run:

c$)$ Extend the library system to manage multiple types of media $($Books$,$ Magazines, DVDs$)$ as follows:

$1.$ Implement an interface Readable with a method void read$().$

$2.$ Create an abstract class Media with an abstract method void displayMediaInfo$()$ and a concrete method boolean isAvailable$().$

$3.$ Extend Media in classes Book, Magazine, and DVD$,$ where Book and Magazine implement Readable.

$4.$ Use a $2$D array to store media in the library as follows:

Media$[][]$ library $=$ new Media$[2][2]$;

library$[0][0]=$ book; $//$ book is created using Book constructor

library$[0][1]=$ magazine; $//$ magazine is created using Magazine constructor

library$[1][0]=$ dvd; $//$ dvd is created using DVD constructor