RoomSync - Hotel Reservation & Management System

Project Overview

RoomSync is a backend-based Hotel Reservation & Management System developed using Spring Boot and MongoDB. The project focuses on managing hotel rooms, customers, and bookings through REST APIs while demonstrating CRUD operations, entity relationships, business logic, and exception handling.

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Project Structure

com.roomsync

├── controller
│      RoomController
│      CustomerController
│      BookingController
│
├── service
│      RoomService
│      CustomerService
│      BookingService
│
├── repository
│      RoomRepository
│      CustomerRepository
│      BookingRepository
│
├── model
│      Room
│      Customer
│      Booking
│
├── exception
│      ResourceNotFoundException
│      RoomNotAvailableException
│      BookingOperationException
│      GlobalExceptionHandler
│
└── RoomSyncApplication

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Entities Given

Room

• roomNumber
• roomType
• price
• status

Customer

• name
• email
• phone

Booking

Booking
 ├── customerId
 ├── roomId
 ├── checkInDate
 ├── checkOutDate
 └── bookingStatus

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Business Proper Flow

Customer
    ↓
Creates Booking
    ↓
Booking references Room
    ↓
Room becomes BOOKED
    ↓
Customer Check-In
    ↓
Room becomes OCCUPIED
    ↓
Customer Check-Out
    ↓
Room becomes AVAILABLE

---

Room Status Proper Flow

AVAILABLE
    ↓
Create Booking
    ↓
BOOKED
    ↓
Check In
    ↓
OCCUPIED
    ↓
Check Out
    ↓
AVAILABLE

---

Booking Status Proper Flow

CREATE BOOKING
      ↓
CONFIRMED
      ↓
CHECKED_IN
      ↓
CHECKED_OUT

Invalid State Changes

CHECKED_OUT → CANCELLED
CHECKED_OUT → CHECKED_IN
CANCELLED → CHECKED_IN
CONFIRMED → CHECKED_OUT

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Validation Logic I used

If:

Room Status = BOOKED

or

Room Status = OCCUPIED

Then:

Room is not available

This prevents a room from being assigned to multiple active bookings.

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CRUD Operations performed Includes

CRUD Operations

Module	Create	Get All	Get By Id	Update	Delete / Cancel
Room	✅	✅	✅	✅	✅
Customer	✅	✅	✅	✅	✅
Booking	✅	✅	✅	✅	✅

---

Booking Management Features

• Create Booking
• Update Booking
• Cancel Booking
• Check-In
• Check-Out
• Room Status Management
• Date Validation
• Global Exception Handling

Example:

public List<Booking> getAllBookings() {
    return bookingRepository.findAll();
}

This method retrieves all booking records and is useful for hotel administration and booking management.

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Exception Handling (A Major Challenge)

Global exception handling is implemented using @ControllerAdvice.

HTTP Status Codes Used

Status Code	Description
404	Resource not found
409	Room unavailable
400	Invalid booking operation
500	Unexpected server error

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Issues Faced and Fixes

Bug 1

if (!booking.getBookingStatus())

Issue: getBookingStatus() returns a String, not a boolean.

Fix: Compared the booking status using defined constants.

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Bug 2

During Check-In, room status was updated to OCCUPIED but booking status was not updated.

Fix:

Booking Status → CHECKED_IN
Room Status → OCCUPIED

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Bug 3

During Check-Out, room status was updated to AVAILABLE but booking status was not updated.

Fix:

Booking Status → CHECKED_OUT
Room Status → AVAILABLE

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Bug 4

Booking dates were not validated.

Example:

Check-In  : 25 Jun 2026
Check-Out : 20 Jun 2026

Fix:

if (!checkOutDate.isAfter(checkInDate))

This ensures the check-out date is always after the check-in date.

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Bug 5 (Major Logical Bug)

Double Booking Prevention

A room cannot be booked if its status is already:

BOOKED
or
OCCUPIED

This prevents multiple active bookings for the same room.

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Future Enhancements

• Authentication & Authorization
• Payment Integration
• Admin Dashboard
• Room Availability Search
• Booking Reports & Analytics

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Author

Shashank Kumar

RoomSync - Hotel Reservation & Management System