FlightTracker

A comprehensive REST API for simulating airline flight operations. Features dynamic pricing, real-time seat management, booking system, and intelligent check-in algorithms.

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🎯 Project Overview

FlightTracker is a backend REST API that simulates real-world airline operations including:

• Flight scheduling and management
• Dynamic pricing algorithms
• Real-time seat inventory
• Passenger booking & cancellation
• Check-in process automation
• Layover/connection management

Built with Spring Boot 3 and Java 17, demonstrating enterprise patterns and clean architecture principles.

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✨ Core Features

Flight Management

• ✅ Create and schedule flights
• ✅ Define routes with layovers
• ✅ Aircraft assignment with seat configurations
• ✅ Flight status tracking
• ✅ Cancellation & rescheduling

Pricing Engine

• ✅ Base fare calculation
• ✅ Dynamic pricing based on:
  • Demand (seat availability)
  • Booking time (early bird discounts)
  • Seat class (economy, business, first)
  • Seasonal multipliers
• ✅ Price history tracking

Booking System

• ✅ Search flights by route & date
• ✅ Reserve seats (with validation)
• ✅ Modify bookings
• ✅ Cancel with refund calculation
• ✅ Booking confirmation & ticket generation

Seat Management

• ✅ Real-time seat availability
• ✅ Seat class distribution
• ✅ Accessible seat tracking
• ✅ Seat hold (temporary reservation)
• ✅ Seat release on cancellation

Check-in Process

• ✅ Online check-in (24hrs before)
• ✅ Baggage assignment
• ✅ Seat confirmation
• ✅ Boarding group assignment
• ✅ Check-in validation

Passenger Management

• ✅ Passenger profile
• ✅ Frequent flyer tracking
• ✅ Special requests (wheelchair, meal)
• ✅ Travel document validation
• ✅ Loyalty points

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🏗️ Architecture

Layered Architecture

┌─────────────────────────────┐
│      REST Controllers       │  API Endpoints
├─────────────────────────────┤
│      Service Layer          │  Business Logic
├─────────────────────────────┤
│      Repository Layer       │  Data Access
├─────────────────────────────┤
│     Database (JPA)          │  PostgreSQL
└─────────────────────────────┘

Key Components

com.flighttracker/
├── api/
│   ├── controller/
│   │   ├── FlightController.java
│   │   ├── BookingController.java
│   │   ├── CheckInController.java
│   │   └── PassengerController.java
│   ├── dto/
│   │   ├── FlightDTO.java
│   │   ├── BookingRequest.java
│   │   └── PriceDTO.java
│   └── exception/
│       └── GlobalExceptionHandler.java
├── service/
│   ├── FlightService.java
│   ├── PricingService.java
│   ├── BookingService.java
│   ├── CheckInService.java
│   └── SeatAvailabilityService.java
├── repository/
│   ├── FlightRepository.java
│   ├── BookingRepository.java
│   ├── PassengerRepository.java
│   └── SeatRepository.java
├── entity/
│   ├── Flight.java
│   ├── Booking.java
│   ├── Passenger.java
│   ├── Seat.java
│   └── CheckIn.java
└── config/
    └── AppConfig.java

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🗄️ Database Schema

Core Tables

-- Airlines & Aircraft
CREATE TABLE airlines (
    id UUID PRIMARY KEY,
    code VARCHAR(3),
    name VARCHAR(100)
);

CREATE TABLE aircraft (
    id UUID PRIMARY KEY,
    airline_id UUID REFERENCES airlines(id),
    model VARCHAR(50),
    registration VARCHAR(10),
    economy_seats INT,
    business_seats INT,
    first_class_seats INT
);

-- Routes & Flights
CREATE TABLE airports (
    id UUID PRIMARY KEY,
    code VARCHAR(3) UNIQUE,
    name VARCHAR(100),
    city VARCHAR(50)
);

CREATE TABLE routes (
    id UUID PRIMARY KEY,
    origin_id UUID REFERENCES airports(id),
    destination_id UUID REFERENCES airports(id),
    distance_km INT
);

CREATE TABLE flights (
    id UUID PRIMARY KEY,
    route_id UUID REFERENCES routes(id),
    aircraft_id UUID REFERENCES aircraft(id),
    departure_time TIMESTAMP,
    arrival_time TIMESTAMP,
    status VARCHAR(50),  -- SCHEDULED, BOARDING, DEPARTED, LANDED
    base_fare DECIMAL(10,2)
);

-- Seats & Availability
CREATE TABLE seats (
    id UUID PRIMARY KEY,
    aircraft_id UUID REFERENCES aircraft(id),
    seat_number VARCHAR(10),
    seat_class VARCHAR(50),  -- ECONOMY, BUSINESS, FIRST
    is_accessible BOOLEAN,
    UNIQUE(aircraft_id, seat_number)
);

CREATE TABLE seat_inventory (
    id UUID PRIMARY KEY,
    flight_id UUID REFERENCES flights(id),
    seat_id UUID REFERENCES seats(id),
    status VARCHAR(50),  -- AVAILABLE, BOOKED, HELD
    held_until TIMESTAMP,
    UNIQUE(flight_id, seat_id)
);

-- Pricing
CREATE TABLE flight_prices (
    id UUID PRIMARY KEY,
    flight_id UUID REFERENCES flights(id),
    seat_class VARCHAR(50),
    base_price DECIMAL(10,2),
    current_price DECIMAL(10,2),
    demand_multiplier DECIMAL(3,2),
    updated_at TIMESTAMP
);

-- Passengers & Bookings
CREATE TABLE passengers (
    id UUID PRIMARY KEY,
    first_name VARCHAR(100),
    last_name VARCHAR(100),
    email VARCHAR(255),
    phone VARCHAR(20),
    passport_number VARCHAR(50),
    frequent_flyer_number VARCHAR(50)
);

CREATE TABLE bookings (
    id UUID PRIMARY KEY,
    flight_id UUID REFERENCES flights(id),
    booking_reference VARCHAR(10) UNIQUE,
    passenger_id UUID REFERENCES passengers(id),
    seat_id UUID REFERENCES seats(id),
    booking_date TIMESTAMP,
    status VARCHAR(50),  -- CONFIRMED, CANCELLED
    price_paid DECIMAL(10,2)
);

-- Check-in
CREATE TABLE check_ins (
    id UUID PRIMARY KEY,
    booking_id UUID REFERENCES bookings(id),
    check_in_time TIMESTAMP,
    gate_number VARCHAR(10),
    boarding_group VARCHAR(5),
    baggage_tags TEXT[]
);

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📚 API Endpoints

Flights

POST /api/v1/flights
Content-Type: application/json

{
  "routeId": "uuid",
  "aircraftId": "uuid",
  "departureTime": "2024-01-15T10:00:00Z",
  "arrivalTime": "2024-01-15T14:30:00Z",
  "baseFare": 250.00
}

GET /api/v1/flights
GET /api/v1/flights/{flightId}

GET /api/v1/flights/search?origin=JFK&destination=LAX&date=2024-01-15

Pricing

GET /api/v1/flights/{flightId}/prices

GET /api/v1/flights/{flightId}/prices/{seatClass}

Response:
{
  "baseFare": 250.00,
  "currentPrice": 320.50,
  "demandMultiplier": 1.28,
  "availableSeats": 25,
  "lastUpdated": "2024-01-10T14:22:00Z"
}

Booking

POST /api/v1/bookings
{
  "flightId": "uuid",
  "passengerId": "uuid",
  "seatId": "uuid",
  "pricePaid": 320.50
}

Response: 201
{
  "bookingId": "uuid",
  "bookingReference": "AB12CD",
  "status": "CONFIRMED",
  "seat": "12A",
  "passenger": { ... }
}

PUT /api/v1/bookings/{bookingId}
DELETE /api/v1/bookings/{bookingId}

Check-in

POST /api/v1/check-in
{
  "bookingReference": "AB12CD",
  "passportNumber": "XX123456"
}

Response:
{
  "boardingPass": {
    "flightNumber": "AA100",
    "seat": "12A",
    "boardingGroup": "B",
    "gate": "A12",
    "boardingTime": "2024-01-15T09:15:00Z"
  }
}

GET /api/v1/check-in/{bookingReference}

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💰 Pricing Algorithm

public class PricingEngine {
    
    // Dynamic price = Base fare × Demand multiplier × Time multiplier
    public BigDecimal calculatePrice(Flight flight, String seatClass) {
        BigDecimal baseFare = flight.getBaseFare();
        
        // Demand multiplier (0.7 to 2.0)
        // High demand = fewer seats available = higher price
        double demandMultiplier = calculateDemandMultiplier(flight);
        
        // Time multiplier (early booking discount)
        // More days until flight = lower price
        double timeMultiplier = calculateTimeMultiplier(flight);
        
        // Seat class surcharge
        double classMultiplier = getSeatClassMultiplier(seatClass);
        
        return baseFare
            .multiply(new BigDecimal(demandMultiplier))
            .multiply(new BigDecimal(timeMultiplier))
            .multiply(new BigDecimal(classMultiplier));
    }
}

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✈️ Check-in Algorithm

1. Validate booking & passenger
2. Check 24-hour rule (< 24hrs to departure)
3. Assign boarding group based on:
   - Frequent flyer status
   - Seat class
   - Check-in order
4. Assign gate (depends on destination distance)
5. Generate baggage tags
6. Issue boarding pass
7. Return to passenger

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🧪 Testing

# Unit tests
mvn test

# Integration tests
mvn test -Dtest=*IntegrationTest

# Test coverage
mvn jacoco:report

# Load testing (if included)
mvn jmeter:gui

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🚀 Running

mvn clean install
mvn spring-boot:run

# API: http://localhost:8080
# Swagger: http://localhost:8080/swagger-ui.html

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📊 Performance

• Optimized queries with proper indexing
• Seat availability cached in-memory
• Price calculations memoized
• Connection pooling with HikariCP

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🔮 Future Enhancements

• Multi-leg journey bookings
• Ancillary services (meals, bags)
• Crew management
• Overbooking simulation
• Revenue optimization
• Mobile boarding pass
• Payment gateway integration

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