StayEase

🏨 Hotel Booking Aggregator – Backend Service

A secure, role-based backend service built using Spring Boot and Gradle with MySQL to manage hotel listings and room bookings for a hotel management aggregator platform. The application exposes RESTful APIs secured with JWT-based authentication and enforces strict role-based authorization and business rules to prevent overbooking and ensure data integrity.

This project follows a clean layered architecture and incorporates production-ready practices such as validation, centralized error handling, logging, and unit testing.

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📌 1. Problem Statement

The goal of this project is to design and implement a backend service for a simplified hotel room booking system that:

• Allows users to register and authenticate securely
• Enables customers to browse hotels and book rooms
• Allows hotel managers to update hotel details and cancel bookings
• Restricts hotel creation and deletion to administrators
• Prevents overbooking by tracking available rooms
• Enforces booking date validation rules
• Secures APIs using JWT and role-based access control

The system assumes:

• Only one type of room
• All bookings are for two guests
• Check-in and check-out handling is managed by another service

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🧰 2. Technology Stack & Rationale

Technology	Purpose
Java 17	Backend programming language
Spring Boot (3.3.3)	Framework for building RESTful APIs
Spring Security	Authentication & authorization
JWT (io.jsonwebtoken:0.11.5)	Stateless authentication
MySQL	Relational database for persistent storage
Spring Data JPA	ORM and database abstraction
BCrypt	Secure password hashing
Gradle	Build and dependency management
JUnit 5 & Mockito	Unit and integration testing
SLF4J / Logback	Logging

Why Gradle? Gradle provides efficient build automation, dependency management, and incremental compilation for faster builds, especially in Spring Boot projects.

Why MySQL? MySQL provides strong transactional guarantees and relational integrity, making it suitable for booking systems where consistency and accuracy are critical.

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🧭 3. High-Level Design (HLD)

Client (Postman / Frontend)
        ↓
Controller Layer
        ↓
Service Layer
        ↓
Repository Layer
        ↓
MySQL Database

Layer Responsibilities

• Controller Layer Handles HTTP requests, request validation, and response mapping

• Service Layer Contains core business logic such as booking rules, room availability checks, and date validation

• Repository Layer Manages database operations using Spring Data JPA

• Security Layer Implements JWT authentication and role-based access control

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👥 4. User Roles & Authorization

Role	Description
USER	Can browse hotels and create bookings
HOTEL_MANAGER	Can update hotel details and cancel bookings
ADMIN	Can create and delete hotels

Access Control Summary

Action	USER	HOTEL_MANAGER	ADMIN
Register / Login	✅	✅	✅
Browse Hotels	✅	✅	✅
Create Hotel	❌	❌	✅
Update Hotel	❌	✅	❌
Delete Hotel	❌	❌	✅
Create Booking	✅	❌	❌
Cancel Booking	❌	✅	❌

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🌟 5. Key Features

🔐 User Management

• User registration and login
• Passwords securely hashed using BCrypt
• JWT token generation on successful authentication
• Default role assignment to USER

🏨 Hotel Management

• Public access to browse available hotels
• Admin-only hotel creation and deletion
• Hotel manager-only updates
• Tracks total and available rooms

📅 Booking Management

• Customers can book one room per request
• Prevents overbooking using available room count
• Only managers can cancel bookings

• Date validation:

  • Check-in must be a future date
  • Check-out must be after check-in
  • Date format: YYYY-MM-DD

🛡️ Security

• Stateless JWT-based authentication
• Role-based endpoint protection
• Separation of public and private endpoints

⚠️ Validation & Error Handling

• Centralized exception handling
• Meaningful HTTP status codes (400, 401, 403, 404)
• Graceful error messages

🧪 Testing

• Unit tests using JUnit and Mockito
• Controller tests using MockMvc
• Coverage for authentication, booking logic, and authorization rules

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📡 6. API Documentation

Base URL

http://localhost:8081

Authentication APIs

Method	Endpoint
POST	/api/users/register
POST	/api/users/login

Hotel APIs

Method	Endpoint	Access
GET	/api/hotels	Public
POST	/api/hotels	ADMIN
PUT	/api/hotels/{hotelId}	HOTEL_MANAGER
DELETE	/api/hotels/{hotelId}	ADMIN

Booking APIs

Method	Endpoint	Access
POST	/api/bookings/{hotelId}	USER
GET	/api/bookings/{bookingId}	Authenticated
DELETE	/api/bookings/{bookingId}	HOTEL_MANAGER

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💻 7. Local Setup & Running the Application

📦 Prerequisites

• Java 17+
• MySQL running locally
• Gradle installed

🔧 Setup Steps

# Clone the repository
git clone <your-github-repo-url>
cd hotel-booking-aggregator

# Configure database
# Update application.properties or application.yml with MySQL credentials

# Build the project
./gradlew clean build

# Run the application
./gradlew bootRun

🌐 Access

http://localhost:8081

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📝 8. Logging & Monitoring

• Uses SLF4J with Logback
• Logs request flow, business operations, and errors
• Helpful for debugging and production monitoring

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🚀 9. Future Enhancements

• Multiple room types per hotel
• Pricing and payment integration
• Booking history for users
• Pagination and filtering for hotels
• Swagger / OpenAPI documentation
• Dockerization and CI/CD pipeline
• Cloud deployment (AWS / GCP)

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📬 10. Contributions & Support

Contributions, issues, and feature requests are welcome. Feel free to open an issue or submit a pull request.

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Maintained by: Shushant Rishav