3rd version of ReservationService - with null check and addition of ReservationNotFoundException

ReservationService3.java

@Service
public class ReservationService {
	private ReservationRepository reservationRepository;
	
	public ReservationService(ReservationRepository reservationRepository) {
		this.reservationRepository = reservationRepository;
	}

	public Reservation getReservationDetails(String name) {
		System.out.println("Entering and leaving ReservationService : getReservationDetails "
				+ "after calling reservationRepository.findByFirstName");
		Reservation aReservation = reservationRepository.findByFirstName(name);
		if (aReservation == null) {
			throw new ReservationNotFoundException();
		}
		return aReservation;
	}
}