A Java-based console application for managing library resources — including books, magazines, and users (students and professors). Built using core Object-Oriented Programming principles: Inheritance, Polymorphism, Abstraction, and Interfaces.
- Features
- Project Structure
- Class Overview
- How to Run
- Usage Guide
- OOP Concepts Used
- Known Limitations
- 📖 Add and remove Books and Magazines
- 👤 Register and manage Students and Professors
- 🔄 Borrow and return library items
- 🔍 View all items or user details by ID
- 🧱 Clean, menu-driven console interface
- 🌱 Pre-loaded demo data on startup
LibraryManagementSystem/
│
├── mainLibraryManagement.java # Entry point — main menu & program flow
│
├── Models/
│ ├── Library_Item.java # Base class for all library items
│ ├── Book.java # Extends Library_Item
│ ├── Magazine.java # Extends Library_Item
│ └── Author.java # Represents a book's author
│
├── Users/
│ ├── User.java # Base class for all users
│ ├── Student.java # Extends User (books only)
│ └── Professor.java # Extends User (books & magazines)
│
├── Library/
│ └── Library.java # Manages the collection of items
│
├── Managers/
│ └── userManager.java # Handles all user registration & lookup
│
└── Interfaces/
├── itemOperations.java # Interface for item operations
├── UserOperations.java # Interface for user operations
├── BooksOperation.java # Interface for book operations (reserved)
└── MagazineOperations.java # Interface for magazine operations (reserved)
The parent class for all items in the library.
| Field | Type | Description |
|---|---|---|
itemId |
String |
Unique identifier |
Tittle |
String |
Title of the item |
isAvailable |
Boolean |
Whether the item can be borrowed |
Key Methods:
borrowItem()— Marks item as borrowedreturnItem()— Marks item as returneddisplayDetails()— Prints item info
Represents a book with an associated Author.
Represents a magazine with an issueNumber.
Stores author details: name, biography, and total books published.
The parent class for library users. Each user can borrow one item at a time.
| Field | Type | Description |
|---|---|---|
userId |
String |
Unique user ID |
name |
String |
User's name |
maxBorrowLimit |
short |
Max items allowed (default: 1) |
Key Methods:
borrow(Library_Item)— Borrows an itemreturnItem()— Returns the currently borrowed itemshowBorrowedItems()— Displays what the user has borrowed
- Can only borrow Books (not magazines)
- Can borrow both Books and Magazines
Maintains an array of up to 10 library items.
| Method | Description |
|---|---|
addItem(item) |
Adds a new item |
removeItem(itemId) |
Removes item by ID |
displayItems() |
Lists all items |
Manages up to 20 users.
| Method | Description |
|---|---|
registerStudent(id, name) |
Registers a new student |
registerProfessor(id, name) |
Registers a new professor |
removeUser(id) |
Removes a user by ID |
displayAllUsers() |
Lists all users |
displayUserById(id) |
Shows details for one user |
findUser(id) |
Returns a User object by ID |
- Java JDK 11 or higher installed
- A terminal or IDE (IntelliJ, Eclipse, VS Code)
1. Clone or download all .java files into one folder.
2. Compile all files:
javac *.java3. Run the main class:
java mainLibraryManagement💡 The system loads 2 demo books and 1 demo magazine automatically on startup.
Once running, you'll see the main menu:
╔══════════════════════════════════════╗
║ LIBRARY MANAGEMENT SYSTEM ║
╠══════════════════════════════════════╣
║ 1. User Management ║
║ 2. Book Management ║
║ 3. Magazine Management ║
║ 4. Borrow / Return ║
║ 0. Exit ║
╚══════════════════════════════════════╝
- Register a new Student or Professor with an ID and name
- Remove a user by their ID
- View all registered users or look up one by ID
- Add a new book by entering ID, title, and author details
- Remove a book by its ID
- View all items in the library
- Add a new magazine with an ID, title, and issue number
- Remove a magazine by ID
- View all items
- Enter your User ID
- A list of available items is shown
- Pick an item number to borrow
- To return, enter your User ID and your item is returned automatically
⚠️ Students can only borrow Books. Professors can borrow both Books and Magazines.
| Concept | Where Applied |
|---|---|
| Inheritance | Book, Magazine extend Library_Item; Student, Professor extend User |
| Polymorphism | displayDetails() overridden in Book and Magazine; borrow() overridden in Student |
| Abstraction | Library_Item and User act as abstract base classes |
| Interfaces | itemOperations, UserOperations define contracts for Library and userManager |
| Encapsulation | Private fields with controlled access via methods across all classes |
- The library can hold a maximum of 10 items and 20 users (fixed array size)
- Each user can only borrow one item at a time
- Data is not persisted — everything resets when the program exits
- The
BooksOperationandMagazineOperationsinterfaces are defined but not yet fully implemented - The
removeItem()method inLibrary.javahas a minor bug where "Item not found" prints for every non-matching entry during a loop (not just when the item is truly absent)
- Add file or database persistence (save/load data)
- Increase borrow limit per user type
- Add search functionality by title or author
- Implement due dates and late fee tracking
- Build a GUI using Java Swing or JavaFX
Built as a Java OOP learning project demonstrating real-world class design, interface-driven development, and clean menu-based console interaction.