Java

What is the difference between map and flatMap operations?

What access modifiers do fields and methods have in default interfaces?

What requirements are imposed on a class for proper work with Hibernate?

Read the code and highlight errors. /** * A client with a purchased ticket can choose a specific seat for an additional fee. * The base price of seats is determined by tariffs (external service). * For clients with certain tariffs (PREMIUM, ULTRA), a discount is applied at payment. * When booking, an invoice is issued to the client for payment. Payment management is handled by a third-party service. */ @Service public class SeatBookingService { @Autowired private SeatBookingRepository seatBookingRepository; @Autowired private TicketRepository ticketRepository; @Autowired private TariffClient tariffClient; @Autowired private CustomerClient customerClient; @Autowired private PaymentClient paymentClient; /** * Booking. * @param seatCode seat code (e.g., 19A) * @param ticketId ticket ID */ @Transactional public void bookSeat(String seatCode, UUID ticketId) { var ticket = ticketRepository.findById(ticketId); //book var seatBooking = new SeatBooking(seatCode, ticket.get().getFlightId(), ticketId, BookingStatus.BOOKED); seatBookingRepository.save(seatBooking); //find base tariff for the selected seat on the plane var basePrice = tariffClient.getBasePrice(ticket.get().getPlaneModel(), seatCode); //find customer data Long userId = (Long) SecurityContextHolder.getContext().getAuthentication().getPrincipal(); var userData = customerClient.getCustomer(userId); System.out.println("User found " + userData.getFio() + " document number " + userData.getDocument()); var price = basePrice; if (userData.getTariff() == "PREMIUM") { //50% discount price = basePrice * 0.5d; } if (userData.getTariff() == "ULTRA") { //20% discount price = basePrice * 0.8d; } var invoice = new Invoice(price, ticketId, userId); //issue invoice paymentClient.sendInvoice(invoice); System.out.println("Invoice issued"); } @Data @Table("seat_booking") public class SeatBooking { @Column private String seatCode; @Column private UUID flightId; @Column private UUID ticketId; @Column private BookingStatus status; } public enum BookingStatus { BOOKED, PAID; }

Senior

Т-Банк

Can you list the types of classes that exist in Kotlin?

Junior — Middle

Aston

What is the difference between the dependency and dependencyManagement sections in a Maven configuration file?

Junior — Middle

IT One

Why are ArrayList and array the fundamental data structures in Java?

What types of table joins have you used in your SQL queries?

In which cases is the Round Robin algorithm optimal?

How can you obtain a stream of elements from a collection as a Map using the Stream API?

How do loops in Java differ?

Have you participated in setting up or working with the stage environment for testing or deployment?

Describe the general practical principles of working with JavaServer Pages (JSP).

How do you use dependency injection in your projects?

How is automatic resource closing implemented using the try-with-resources construct?

What happens when an exception is thrown in a thread?

What is an XSD schema?

Which method within an object do you think is the most important and frequently used?

Can the use of a component be replaced with a service in Spring, and which of these alternatives is more preferable?

Какое отличие между модификаторами доступа protected и package-private (default) в языке Java?