Library Management System

A Java desktop application demonstrating industry best practices, clean architecture, and modern software design patterns.

🎯 Overview

This project is a complete Library Management System built with:

• Core Java (OOP principles)
• Layered Architecture (Model-Service-Repository pattern)
• Swing GUI with tabs and tables
• CSV & JDBC persistence (CSV by default, MySQL optional)
• Authentication system (Admin/Guest roles)
• Fine calculation for late book returns
• Comprehensive error handling and validation

Perfect for: Portfolio, interview prep, learning Java architecture patterns.

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✨ Key Features

📚 Book Management

• ✅ Add new books (title, author)
• ✅ View all books in table format
• ✅ Search books by ID or title
• ✅ Delete books (admin-only)
• ✅ Track availability status
• ✅ Monitor issue/return dates

👥 User Management

• ✅ Add new users/students
• ✅ View all registered users
• ✅ User lookup by ID/name
• ✅ User role management (future)

📤 Issue & Return System

• ✅ Issue books to users
• ✅ Track issue date (stored)
• ✅ Return books with automatic fine calculation
• ✅ Fine: Rs. 5 per day after 14-day limit
• ✅ Display fine amount on return

🔐 Authentication & Authorization

• ✅ Admin login (admin/admin123)
• ✅ Guest login (guest/guest)
• ✅ Role-based UI (admin-only features hidden for guests)
• ✅ Session management

💾 Data Persistence

• ✅ CSV file storage (default, no database needed)
• ✅ JDBC MySQL support (optional, configurable)
• ✅ Automatic data load on startup
• ✅ Real-time save on all operations

⚙️ Configuration

• ✅ Centralized AppConfig.java
• ✅ Toggle CSV vs JDBC mode
• ✅ Customizable fine policy
• ✅ Database credentials in one place

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File Structure

javProject/
├── AppConfig.java                 # Configuration & constants
├── Book.java                      # Book model with CSV serialization
├── User.java                      # User model with CSV serialization
├── FineCalculator.java            # Fine calculation logic
│
├── LibraryRepository.java         # Repository interface (contract)
├── CsvLibraryRepository.java      # CSV-based persistence
├── JdbcLibraryRepository.java     # MySQL-based persistence
├── RepositoryException.java       # Custom exception
├── NotFoundException.java         # Custom exception
│
├── LibraryService.java            # Core business logic
├── AuthService.java               # Authentication & role management
│
├── LibraryGUI.java                # Swing UI (main view)
├── Main.java                      # Entry point
│
├── DatabaseManager.java           # Utility for DB operations
├── books.csv                      # Auto-generated (CSV mode)
├── users.csv                      # Auto-generated (CSV mode)
└── README.md                      # This file

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🛠️ Technology Stack

Layer	Technology
Language	Java 8+
UI Framework	Swing (javax.swing)
Data Storage	CSV (default) / MySQL 5.7+ (optional)
JDBC	MySQL Connector/J
Design Pattern	MVC / Layered Architecture
Build	javac (no build tool required)

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Compile

javac *.java

All .class files generated in same directory.

Run

java Main

GUI window opens automatically.

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🚀 Quick Start

1. Login

• Username: admin
• Password: admin123

2. Add a Book (Admin only)

• Go to Books tab
• Enter Title: Harry Potter
• Enter Author: J.K. Rowling
• Click Add Book

3. Add a User (Admin only)

• Go to Users tab
• Enter User Name: John Doe
• Click Add User

4. Issue a Book

• Go to Issue/Return tab
• Enter Book ID: 1
• Enter User ID: 1
• Click Issue Book

5. Return a Book

• Go to Issue/Return tab
• Enter Book ID: 1
• Click Return Book
• ✅ Fine calculated automatically

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⚙️ Configuration

Open AppConfig.java:

public class AppConfig {
    // Storage mode
    public static final boolean USE_JDBC = false;  // Set true for MySQL

    // MySQL config (if USE_JDBC=true)
    public static final String JDBC_URL = "jdbc:mysql://localhost:3306/librarydb?useSSL=false&serverTimezone=UTC";
    public static final String JDBC_USER = "root";
    public static final String JDBC_PASSWORD = "password";

    // Fine policy (in Rupees, per day)
    public static final int MAX_BOOK_ISSUE_DAYS = 14;
    public static final int FINE_PER_LATE_DAY = 5;

    // Default credentials
    public static final String ADMIN_USERNAME = "admin";
    public static final String ADMIN_PASSWORD = "admin123";
    public static final String GUEST_USERNAME = "guest";
    public static final String GUEST_PASSWORD = "guest";
}

Switch to MySQL Mode

1. Set USE_JDBC = true in AppConfig.java
2. Create database:

   CREATE DATABASE librarydb;

3. Update JDBC credentials if different
4. Recompile and run:

   javac *.java
   java Main

Tables auto-create on first run.

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🔐 Authentication & Authorization

Role	Access
Admin	Add/delete books, add users, view all
Guest	View books, issue/return, view users (read-only)

Login Credentials

Type	Username	Password
Admin	admin	admin123
Guest	guest	guest

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💰 Fine Calculation System

Policy

• Issue Period: 14 days (default)
• Fine: Rs. 5 per day after limit
• Formula: Fine = (Days Used - 14) × 5 (if Days Used > 14)

Example

• Book issued: 2026-03-26
• Book returned: 2026-04-15 (20 days later)
• Late days: 20 - 14 = 6 days
• Fine: 6 × 5 = Rs. 30

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🗄️ Database Setup (MySQL Mode)

Create Database

CREATE DATABASE librarydb;
USE librarydb;

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❌ Troubleshooting

Issue: java.lang.ClassNotFoundException

Solution: Ensure all .java files compiled:

javac *.java

Issue: NotFoundException: Book not found: 999

Solution: Check book ID exists. Use Search to find valid IDs.

Issue: SQLException when USE_JDBC=true

Solution:

1. Verify MySQL running: mysql -u root -p
2. Database exists: SHOW DATABASES; → check librarydb
3. Update credentials in AppConfig.java
4. Recompile: javac *.java

Issue: FileNotFoundException: books.csv

Solution: First run creates files automatically. If error persists:

rm *.csv
javac *.java
java Main

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👨‍💻 Author

Logic Assisted by AI (ChatGPT, Claude)

Your Name
GitHub: [Mani Singh] (https://github.com/mani1505-star/Library_Management_System.git)