Airline reservation systemAirline reservation system

Airline reservation systemAirline reservation system

Java Code

import java.io.File;
import java.io.FileWriter;
import java.io.IOException;
import java.util.Scanner;
import javax.xml.parsers.DocumentBuilder;
import javax.xml.parsers.DocumentBuilderFactory;
import javax.xml.parsers.ParserConfigurationException;
import org.w3c.dom.Document;
import org.w3c.dom.Element;
import org.w3c.dom.Node;
import org.w3c.dom.NodeList;
import org.xml.sax.SAXException;
 
public class AirlineReservationSystem {
    private static final String DATABASE_FILE = "database.xml";
    private static final Scanner scanner = new Scanner(System.in);
 
    public static void main(String[] args) {
        try {
            loadDatabase();
 
            while (true) {
                System.out.println("Airline Reservation System");
                System.out.println("1. Make a reservation");
                System.out.println("2. Cancel a reservation");
                System.out.println("3. Display reservations");
                System.out.println("4. Exit");
                System.out.print("Enter your choice: ");
                int choice = scanner.nextInt();
                scanner.nextLine(); // Consume newline
 
                switch (choice) {
                    case 1:
                        makeReservation();
                        break;
                    case 2:
                        cancelReservation();
                        break;
                    case 3:
                        displayReservations();
                        break;
                    case 4:
                        saveDatabase();
                        System.exit(0);
                        break;
                    default:
                        System.out.println("Invalid choice. Please try again.");
                }
            }
        } catch (ParserConfigurationException | SAXException | IOException e) {
            e.printStackTrace();
        }
    }
 
    private static void makeReservation() throws IOException {
        System.out.print("Enter passenger name: ");
        String passengerName = scanner.nextLine();
 
        System.out.print("Enter flight number: ");
        String flightNumber = scanner.nextLine();
 
        System.out.print("Enter date of travel: ");
        String dateOfTravel = scanner.nextLine();
 
        System.out.print("Enter seat number: ");
        String seatNumber = scanner.nextLine();
 
        Element reservation = createReservationElement(passengerName, flightNumber, dateOfTravel, seatNumber);
        appendReservationToDatabase(reservation);
 
        System.out.println("Reservation created successfully.");
    }
 
    private static Element createReservationElement(String passengerName, String flightNumber,
                                                    String dateOfTravel, String seatNumber) {
        Document doc = getDocument();
        Element reservation = doc.createElement("Reservation");
 
        Element passengerNameElement = doc.createElement("PassengerName");
        passengerNameElement.appendChild(doc.createTextNode(passengerName));
        reservation.appendChild(passengerNameElement);
 
        Element flightNumberElement = doc.createElement("FlightNumber");
        flightNumberElement.appendChild(doc.createTextNode(flightNumber));
        reservation.appendChild(flightNumberElement);
 
        Element dateOfTravelElement = doc.createElement("DateOfTravel");
        dateOfTravelElement.appendChild(doc.createTextNode(dateOfTravel));
        reservation.appendChild(dateOfTravelElement);
 
        Element seatNumberElement = doc.createElement("SeatNumber");
        seatNumberElement.appendChild(doc.createTextNode(seatNumber));
        reservation.appendChild(seatNumberElement);
 
        return reservation;
    }
 
    private static void appendReservationToDatabase(Element reservation) throws IOException {
        Document doc = getDocument();
        Node root = doc.getDocumentElement();
        root.appendChild(reservation);
        saveDatabase();
    }
 
    private static void cancelReservation() throws IOException {
        System.out.print("Enter flight number: ");
        String flightNumber = scanner.nextLine();
 
        System.out.print("Enter seat number: ");
        String seatNumber = scanner.nextLine();
 
        boolean reservationCancelled = removeReservationFromDatabase(flightNumber, seatNumber);
 
        if (reservationCancelled) {
            System.out.println("Reservation cancelled successfully.");
        } else {
            System.out.println("No matching reservation found.");
        }
    }
 
    private static boolean removeReservationFromDatabase(String flightNumber, String seatNumber) throws IOException {
        Document doc = getDocument();
        Node root = doc.getDocumentElement();
        NodeList reservationList = root.getChildNodes();
 
        for (int i = 0; i < reservationList.getLength(); i++) {
            Node reservationNode = reservationList.item(i);
 
            if (reservationNode.getNodeType() == Node.ELEMENT_NODE) {
                Element reservation = (Element) reservationNode;
 
                String savedFlightNumber = reservation.getElementsByTagName("FlightNumber").item(0).getTextContent();
                String savedSeatNumber = reservation.getElementsByTagName("SeatNumber").item(0).getTextContent();
 
                if (savedFlightNumber.equals(flightNumber) && savedSeatNumber.equals(seatNumber)) {
                    root.removeChild(reservation);
                    saveDatabase();
                    return true;
                }
            }
        }
 
        return false;
    }
 
    private static void displayReservations() throws IOException {
        Document doc = getDocument();
        Node root = doc.getDocumentElement();
        NodeList reservationList = root.getChildNodes();
 
        System.out.println("Reservations:");
        for (int i = 0; i < reservationList.getLength(); i++) {
            Node reservationNode = reservationList.item(i);
 
            if (reservationNode.getNodeType() == Node.ELEMENT_NODE) {
                Element reservation = (Element) reservationNode;
 
                String passengerName = reservation.getElementsByTagName("PassengerName").item(0).getTextContent();
                String flightNumber = reservation.getElementsByTagName("FlightNumber").item(0).getTextContent();
                String dateOfTravel = reservation.getElementsByTagName("DateOfTravel").item(0).getTextContent();
                String seatNumber = reservation.getElementsByTagName("SeatNumber").item(0).getTextContent();
 
                System.out.println("Passenger: " + passengerName);
                System.out.println("Flight: " + flightNumber);
                System.out.println("Date of Travel: " + dateOfTravel);
                System.out.println("Seat Number: " + seatNumber);
                System.out.println("---------------------");
            }
        }
    }
 
    private static Document getDocument() throws ParserConfigurationException {
        DocumentBuilderFactory factory = DocumentBuilderFactory.newInstance();
        DocumentBuilder builder = factory.newDocumentBuilder();
        Document doc = builder.newDocument();
 
        try {
            doc = builder.parse(DATABASE_FILE);
            doc.getDocumentElement().normalize();
        } catch (SAXException | IOException e) {
            // Database file does not exist, create a new document with root element
            Element rootElement = doc.createElement("Reservations");
            doc.appendChild(rootElement);
        }
 
        return doc;
    }
 
    private static void loadDatabase() throws ParserConfigurationException, SAXException, IOException {
        File file = new File(DATABASE_FILE);
 
        if (!file.exists()) {
            // Database file does not exist, create a new document with root element
            DocumentBuilderFactory factory = DocumentBuilderFactory.newInstance();
            DocumentBuilder builder = factory.newDocumentBuilder();
            Document doc = builder.newDocument();
            Element rootElement = doc.createElement("Reservations");
            doc.appendChild(rootElement);
            saveDatabase();
        }
    }
 
    private static void saveDatabase() throws IOException {
        Document doc = getDocument();
        FileWriter writer = new FileWriter(DATABASE_FILE);
        XmlUtils.writeDocument(doc, writer);
        writer.close();
    }
}
 

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