📚 Library Management System (Java Console Application)

A feature-rich Library Management System built in Java using the console. This project is designed to manage library operations such as book borrowing, returning, fine tracking, and transaction logging — all with persistent storage using serialization.

---

✅ Features

• 📖 Book Management
  • Add, Delete, Search, List books
• 👤 User Registration & Login
  • Each user has their own borrowing history
• 🔄 Borrow & Return Books
  • Books can only be borrowed if they are available
• ⏰ Due Date Tracking
  • Books must be returned within 7 days
• 💰 Fine System
  • ₹10/day fine after due date
  • Borrowing is blocked if outstanding fine > ₹50
  • Users can pay partial or full fine via "Pay Fine" menu
• 📂 Data Persistence
  • All user and book data is stored using .ser files
• 🧾 Transaction Logging
  • All borrow and return operations are logged to a text file
• 📈 Admin Dashboard
  • View total fines collected across all users
• 📑 Export to CSV
  • Export current book list to books.csv
• 🔒 Admin Mode
  • Protected with password (admin123 by default)

---

🧪 Sample Data

The repository includes a sample books.csv file under data/ so you can test the system immediately after cloning. Other files like .ser and logs are generated after first run and are excluded from GitHub using .gitignore.

---

🛠️ Technologies Used

• Language: Java (Object-Oriented Programming, Collections)
• Persistence: Java Serialization (.ser files)
• Logging: Text-based logging via transaction_log.txt
• I/O: Reading/writing CSV, file-based storage

---

📁 Project Structure

LibraryManagementSystem/
│
├── data/ # Stores persistent and runtime data
│ ├── books.csv # Sample book data (versioned)
│ ├── users_data.ser # Saved user objects (ignored in Git)
│ ├── library_data.ser # Saved book objects (ignored in Git)
│ └── transaction_log.txt # Log of all transactions (ignored in Git)
│
├── src/ # Java source code
│ ├── Main.java # Entry point
│ ├── models/
│ │ ├── Book.java
│ │ └── User.java
│ ├── services/
│ │ ├── LibraryService.java
│ │ └── FileHandler.java
│ └── utils/
│ └── TransactionLogger.java
│
├── README.md # This file
└── .gitignore # Git ignore rules

🚀 How to Run

1. Clone the repository

   git clone https://github.com/dinesh38555/Library-Management-System.git
   cd Library-Management-System

2. Compile the Java code

   javac -d bin src/**/*.java

3. Run the application

   java -cp bin Main

4. Use the Console Menu

   Choose between User or Admin access. Register/Login → Borrow books → Return books → Pay fines.

🔐 Admin Login

Default Password: admin123

(Can be changed in LibraryService.java's adminPassword field)

Admin options include:

• View all transaction logs
• View total fines collected
• Export books list to CSV

💵 Fine System Logic

• Every borrowed book has a 7-day deadline.
• After 7 days, a fine of ₹10/day is applied.
• Borrowing is blocked until the total outstanding fine is ₹50 or less.
• Users can pay partial or full fines using the menu.
• Admin can track total fines collected across all users.

📊 Demo Tips

To effectively test the fine system without waiting:

• Simulate a late return:
  1. Borrow a book as a user.
  2. Temporarily modify the borrowedDate in your code (e.g., in LibraryService.java, you can set book.setBorrowedDate(LocalDate.now().minusDays(10));). Remember to remove this line after testing.
  3. Return the book to observe the fine calculation.
• Pay the fine: Use the "Pay the pending fines" option from the user menu.
• Verify as Admin: Switch to admin mode to view transaction logs and total collected fines.

📝 Notes

• Runtime data (*.ser, transaction_log.txt) is not pushed to GitHub.
• Only books.csv is tracked for demo/testing.
• The entire application runs in the console — no GUI required. You can easily extend this to a JavaFX/Swing GUI.

---

📣 Contributions

Want to improve this system? Feel free to fork the repository and raise a pull request! Ideas for features include:

• GUI (JavaFX or Swing)
• Role-based access
• Search filters
• REST API backend
• SQLite or MySQL integration

---

📄 License

This project is licensed under the MIT License.