@Service
public class NoteService {
    private final NoteRepository repo;

    public NoteService(NoteRepository repo) {
        this.repo = repo;
    }

    @Transactional
    public Note rename(Long id, String text) {
        Note note = repo.findById(id)
            .orElseThrow(() -> new ResponseStatusException(HttpStatus.NOT_FOUND));
        note.setText(text);
        return note;
    }
}