Online Library Management System

A full-stack web application for managing a library of books with user authentication.

Features

• User authentication with JWT tokens
• Add, edit, delete, and view books
• Secure password hashing with bcryptjs
• RESTful API with Express.js
• MongoDB for data persistence
• Responsive web interface

Prerequisites

• Node.js (v14 or higher)
• MongoDB (local or cloud instance)
• npm (comes with Node.js)

Installation

1. Clone the repository

   git clone https://github.com/PavaniP03/Online-Library-Management-system.git
   cd Online-Library-Management-system

2. Install dependencies

   npm install

3. Set up environment variables

   cp .env.example .env

   Edit .env and configure:

   MONGODB_URI=mongodb://localhost:27017/online-library
   JWT_SECRET=your_super_secret_key_change_this_in_production
   PORT=3000
   NODE_ENV=development
   

4. Create a test user (optional)

   Edit createUser.js with desired credentials and run:

   node createUser.js

   Or create through the API after starting the server.

5. Add sample books (optional)

   Run to populate database with sample books:

   node insertBooks.js

Running the Application

Development

npm start

The application will be available at http://localhost:3000

Default Credentials (if using createUser.js)

• Username: yourusername
• Password: yourpassword

Project Structure

.
├── server.js              # Express server and API routes
├── public/
│   ├── index.html        # Frontend HTML
│   ├── scripts.js        # Frontend JavaScript
│   └── styles.css        # Frontend CSS
├── createUser.js         # Utility to create test users
├── insertBooks.js        # Utility to insert sample books
├── package.json          # Dependencies
├── .env.example          # Environment variables template
├── .gitignore            # Git ignore rules
└── README.md             # This file

API Endpoints

Authentication

• POST /api/login - Login with username and password
  • Body: { "username": "user", "password": "pass" }
  • Returns: { "username": "user", "token": "jwt_token" }

Books (requires authentication)

All book endpoints require the Authorization: Bearer <token> header.

• GET /api/books - Get all books
• POST /api/books - Add a new book
  • Body: { "title": "Book Title", "author": "Author Name" }
• PUT /api/books/:id - Update a book
  • Body: { "title": "New Title", "author": "New Author" }
• DELETE /api/books/:id - Delete a book

Deployment

Heroku

1. Create a Heroku app: heroku create your-app-name
2. Add MongoDB Atlas URI: heroku config:set MONGODB_URI="your_atlas_uri"
3. Set JWT secret: heroku config:set JWT_SECRET="your_secret_key"
4. Deploy: git push heroku main

Other Platforms

• Set environment variables on the hosting platform
• Ensure MongoDB is accessible
• Run npm install && npm start

Production Checklist

• Change JWT_SECRET to a strong, unique key
• Use MongoDB Atlas or another cloud database service
• Set NODE_ENV=production
• Enable HTTPS
• Set FRONTEND_URL environment variable for CORS
• Add input validation and sanitization
• Implement rate limiting
• Add database backups
• Monitor application logs

Security Notes

• JWT tokens expire after 24 hours
• Passwords are hashed using bcryptjs
• CORS is configured for security
• Environment variables should never be committed

Troubleshooting

MongoDB Connection Error

• Ensure MongoDB is running locally or provide a valid MongoDB URI
• Check MONGODB_URI in .env

JWT Token Issues

• Clear browser localStorage: localStorage.clear()
• Restart the server
• Verify JWT_SECRET matches between frontend and backend

Port Already in Use

• Change PORT in .env
• Or kill process using the port

License

ISC

Author

PavaniP03

Support

For issues or questions, please open a GitHub issue.