How does spring boot initialise repository

Question

@Repository
public interface RoomRepository extends CrudRepository<Room, Long>{
    Room findByNumber(String number);
}

I have the RoomRepository above

@Service
public class ReservationService {
    private RoomRepository roomRepository;
    private GuestRepository guestRepository;
    private ReservationRepository reservationRepository;

    @Autowired
    public ReservationService(RoomRepository roomRepository, GuestRepository guestRepository, ReservationRepository reservationRepository) {
        this.roomRepository = roomRepository;
        this.guestRepository = guestRepository;
        this.reservationRepository = reservationRepository;
    }

My service class is shown above. Why can spring initialize an interface? Thank you

Probably you can find answer here http://stackoverflow.com/questions/33999879/spring-data-autowire-the-repository-interfaces-directly — Vijendra Kumar Kulhade, Apr 09 '17 at 03:23
Possible duplicate of [How are Spring Data repositories actually implemented?](http://stackoverflow.com/questions/38509882/how-are-spring-data-repositories-actually-implemented) — dunni, Apr 09 '17 at 08:58

score 0 · Answer 1 · edited May 23 '17 at 11:46

0

Spring is creating a proxy for the interface, the proxy delegates all calls to an already existing implementation. This post contains an excellent explanation

edited May 23 '17 at 11:46

Community

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answered Apr 09 '17 at 08:05

Stefan Isele - prefabware.com

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How does spring boot initialise repository

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