Updated AddBookServlet and RemoveBookServlet; improved login handling

[shivenyadavs]

Description of Change

References

Type of change

• Bug fix (non-breaking change which fixes an issue)
• New feature (non-breaking change which adds functionality)
• Breaking change (fix or feature that would cause existing functionality to not work as expected)
• This change requires a documentation update

Checklist

• Added description of change
• Relevant documentation/comments is changed or added
• Search previous suggestions before making a new one, as yours may be a duplicate.
• I have performed a self-review of my own code by running the project in local
• I acknowledge that all my contributions will be made under the project's license.

Notes:

[shivenyadavs]

Updated AddBookServlet and RemoveBookServlet; Improved Login Handling

• Enhanced AddBookServlet to validate inputs and handle exceptions more effectively.
• Refactored RemoveBookServlet to streamline the removal process and improve user feedback.
• Implemented improved login handling mechanisms, including:
  • Better session management for logged-in users.
  • Enhanced error messages for failed login attempts.
  • Input sanitization to prevent SQL injection and enhance security.

These updates improve the overall user experience and ensure more robust server-side logic.