📚 Library Management System (OOP in Java)

🔹 Objective

A mini library management system built using Java OOP concepts.
Covers Abstraction, Encapsulation, Inheritance, and Polymorphism.

🔹 Classes

• Book – Stores book details and issue status.
• User – Represents library members and tracks issued books.
• Library – Manages books, users, issue & return operations.
• Main – Entry point to test the system.

🔹 Features

✅ Add books and users
✅ Issue and return books
✅ Display all books and users
✅ Encapsulation via private fields + getters/setters
✅ Polymorphism using toString() method

🔹 Example Run