📚 Library Management System

A console-based Java application demonstrating Exception Handling, Object-Oriented Programming, and Collections through a simple library management system.

---

📌 Overview

This project implements a basic library system where users can add, list, borrow, and return books. The core focus of this implementation is to demonstrate how to create and handle Custom Exceptions to manage invalid states and business logic errors gracefully.

---

✨ Key Features

Category	Feature	Description
📖 Book Management	Validation	Ensures books have valid titles and positive page counts
🏛️ Library Operations	Add & List	Add books to the library and display the inventory
	Borrow & Return	Simulate borrowing and returning books by title
⚠️ Exception Handling	Custom Exceptions	Tailored exceptions for specific library errors
	Try-Catch Blocks	Robust error handling in the main execution flow

---

🚨 Custom Exceptions

Exception Class	Trigger Condition
InvalidBookException	Thrown when trying to add a null book to the library
EmptyLibraryException	Thrown when listing books or borrowing from an empty library
BookNotFoundException	Thrown when trying to borrow/return a book that doesn't exist
IllegalArgumentException	Thrown when creating a book with invalid title or page count

---

📁 Project Structure

File	Type	Responsibility
Book.java	Entity	Represents a book with title and page count validation
Library.java	Manager	Handles book collection, borrowing, and returning logic
BookNotFoundException.java	Exception	Custom exception for missing books
EmptyLibraryException.java	Exception	Custom exception for empty library state
InvalidBookException.java	Exception	Custom exception for invalid book objects
Main.java	Entry Point	Demonstrates the system workflow and exception handling

---

🚀 Quick Start

1. Compile

Ensure all files are in the Management package directory, then compile:

javac Management/*.java

2. Run

java Management.Main

(Or run Main.java directly from your IDE)

---

💻 Usage Example

Library library = new Library();

try {
    // Add a valid book
    Book book = new Book("Clean Code", 400);
    library.addBook(book);
    
    // Borrow the book
    library.borrowBook("Clean Code");
    
} catch (InvalidBookException | BookNotFoundException e) {
    System.out.println("Error: " + e.getMessage());
}

---

📊 Sample Output

Library is empty
Title cannot be empty
Page count must be positive
Book should not be null.
Book should not be null.
Books in Library :
Clean Code(400pages)
this book (Clean Code(400pages)) has been successfully loaned
return Cannot. title with Book Clean Code not found
this book (Clean Code(400pages)) has been successfully returned

---

---

📝 License

This project is created for educational purposes to demonstrate Java Exception Handling concepts.

---

_{Built with ☕ Java & 🛡️ Custom Exceptions}