Code for the Airline Management System

Write the object-oriented code to implement the design of the airline management system problem.

We'll cover the following

The airline management system classes
Wrapping up

We’ve reviewed different aspects of the airline management system and observed the attributes attached to the problem using various UML diagrams. Let’s explore the more practical side of things, where we will work on implementing the airline management system using multiple languages. This is usually the last step in an object-oriented design interview process.

We have chosen the following languages to write the skeleton code of the different classes present in the airline management system:

Java
C#
Python
C++
JavaScript

The airline management system classes#

In this section, we’ll provide the skeleton code of the classes designed in the class diagram lesson.

Note: For simplicity, we are not defining getter and setter functions. The reader can assume that all class attributes are private and accessed through their respective public getter methods and modified only through their public methods function.

Constants#

The following code provides the definition of the various enums and custom data types being used in the airline management system:

Note: JavaScript does not support enumerations, so we will be using the Object.freeze() method as an alternative that freezes an object and prevents further modifications.

public class Address {
  private int zipCode;
  private String streetAddress;
  private String city;
  private String state;
  private String country;
}
enum AccountStatus {
  ACTIVE,
  DISABLED,
  CLOSED,
  BLOCKED
}
enum SeatStatus {
  AVAILABLE,
  BOOKED,
  CHANCE
}
enum SeatType {
  REGULAR,
  ACCESSIBLE,
  EMERGENCY_EXIT,
  EXTRA_LEG_ROOM
}
enum SeatClass {
  ECONOMY,
  ECONOMY_PLUS,

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Constant definitions

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The Account and Passenger classes

public abstract class Person {
  private String name;
  private Address address;
  private String email;
  private String phone;
  private Account account;
}
public class Admin extends Person {
  public boolean addAircraft(Aircraft aircraft);
  public boolean addFlight(Flight flight);
  public boolean cancelFlight(Flight flight);
  public boolean assignCrew(Flight flight);
  public boolean blockUser(User user);
  public boolean unblockUser(User user);
}
public class Crew extends Person {
  public List<FlightInstance> viewSchedule();
}
public class FrontDeskOfficer extends Person {
  public List<Itinerary> viewItinerary();
  public boolean createItinerary();
  public boolean createReservation();
  public boolean assignSeat();
  public boolean makePayment();
}
public class Customer extends Person {
  private int customerId;

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Person and its derived classes

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The Seat and FlightSeat classes

public class Flight {
  private String flightNo;
  private int durationMin;
  private Airport departure;
  private Airport arrival;
  private List<FlightInstance> instances;
}
public class FlightInstance {
  private Flight flight;
  private Date departureTime;
  private String gate;
  private FlightStatus status;
  private Aircraft aircraft;
  private List<FlightSeat> seats;
}

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The Flight and FlightInstance classes

public class Itinerary {
  private Airport startingAirport;
  private Airport finalAirport;
  private Date creationDate;
  private List<FlightReservation> reservations;
  private List<Passenger> passengers;
  public boolean makeReservation();
  public boolean makePayment();
}
public class FlightReservation {
  private String reservationNumber;
  private FlightInstance flight;
  private HashMap<Passenger, FlightSeat> seatMap;
  private ReservationStatus status;
  private Date creationDate;
  public static FlightReservation fetchReservationDetails(String reservationNumber);
  public List<Passenger> getPassengers();
}

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The Itinerary and FlightReservation classes

public abstract class Payment {
  private int paymentId;
  private double amount;
  private PaymentStatus status;
  private Date timestamp;
  public abstract boolean makePayment();
}
public class Cash extends Payment {
    public boolean makePayment() {
        // functionality
    }
}
public class CreditCard extends Payment {
    private String nameOnCard;
    private String cardNumber;
    public boolean makePayment() {
        // functionality
    }
}

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Payment and its derived classes

public abstract class Notification {
    private int notificationId;
    private Date createdOn;      
    private String content;
    public abstract void sendNotification(Account account);
}
class SmsNotification extends Notification {
    public void sendNotification(Account account) {
        // functionality 
    }
}
class EmailNotification extends Notification {
    public void sendNotification(Account account) {
        // functionality 
    }
}

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Notification and its derived classes

public interface Search {
  // Interface method (does not have a body)
  public List<FlightInstance> searchFlight(Airport source, Airport dest, Date arrival, Date departure);
}
public class SearchCatalog implements Search {
  private HashMap<Quartet<Airport, Airport, Date, Date>, List<FlightInstance>> flights;
  public List<FlightInstance> searchFlight(Airport source, Airport dest, Date arrival, Date departure) {
    // functionality
  }
}

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The Search interface and the SearchCatalog class

public class Airport {
  private String name;
  private String code;
  private Address address;
  private List<Flight> flights;
}
public class Aircraft {
  private String name;
  private String code;
  private String model;
  private int seatCapacity;
  private List<Seat> seats;
}
public class Airline {
  private String name;
  private String code;
  private List<Flight> flights;
  private List<Aircraft> aircrafts;
  private List<Crew> crew;
  
  // The Airline is a singleton class that ensures it will have only one active instance at a time
  private static Airline airline = null;
  
  // Created a static method to access the singleton instance of Airline class
  public static Airline getInstance() {
    if (airline == null) {
      airline = new Airline();
    }
    return airline;

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The Airport, Aircraft, and Airline classes

Activity Diagram for the Airline Management System

Getting Ready: The Cricinfo System