[Spring Java] identify transactional business services boundaries
作者:互联网
If one request failed, we want to keep database untouched as if the request never happen.
Spring makes it easy to add:
@Transactional
To the method or Class:
For example:
@Service @Transactional public class TourRatingService { private TourRatingRepository tourRatingRepository; private TourRepository tourRepository; /** * Construct TourRatingService * * @param tourRatingRepository Tour Rating Repository * @param tourRepository Tour Repository */ @Autowired public TourRatingService(TourRatingRepository tourRatingRepository, TourRepository tourRepository) { this.tourRatingRepository = tourRatingRepository; this.tourRepository = tourRepository; } /** * Create a new Tour Rating in the database * * @param tourId tour identifier * @param customerId customer identifier * @param score score of the tour rating * @param comment additional comment * @throws NoSuchElementException if no Tour found. */ public void createNew(int tourId, Integer customerId, Integer score, String comment) throws NoSuchElementException { tourRatingRepository.save(new TourRating(verifyTour(tourId), customerId, score, comment)); } /** * Get a page of tour ratings for a tour. * * @param tourId tour identifier * @param pageable page parameters to determine which elements to fetch * @return Page of TourRatings * @throws NoSuchElementException if no Tour found. */ public Page<TourRating> lookupRatings(int tourId, Pageable pageable) throws NoSuchElementException { return tourRatingRepository.findByTourId(verifyTour(tourId).getId(), pageable); } /** * Update some of the elements of a Tour Rating. * * @param tourId tour identifier * @param score score of the tour rating * @param comment additional comment * @return Tour Rating Domain Object * @throws NoSuchElementException if no Tour found. */ public TourRating update(int tourId, Integer customerId, Integer score, String comment) throws NoSuchElementException { TourRating rating = verifyTourRating(tourId, customerId); rating.setScore(score); rating.setComment(comment); return tourRatingRepository.save(rating); } /** * Update all of the elements of a Tour Rating. * * @param tourId tour identifier * @param customerId customer identifier * @param score score of the tour rating * @param comment additional comment * @return Tour Rating Domain Object * @throws NoSuchElementException if no Tour found. */ public TourRating updateSome(int tourId, Integer customerId, Integer score, String comment) throws NoSuchElementException { TourRating rating = verifyTourRating(tourId, customerId); if (score != null) { rating.setScore(score); } if (comment!= null) { rating.setComment(comment); } return tourRatingRepository.save(rating); } /** * Delete a Tour Rating. * * @param tourId tour identifier * @param customerId customer identifier * @throws NoSuchElementException if no Tour found. */ public void delete(int tourId, Integer customerId) throws NoSuchElementException { TourRating rating = verifyTourRating(tourId, customerId); tourRatingRepository.delete(rating); } /** * Get the average score of a tour. * * @param tourId tour identifier * @return average score as a Double. * @throws NoSuchElementException */ public Double getAverageScore(int tourId) throws NoSuchElementException { List<TourRating> ratings = tourRatingRepository.findByTourId(verifyTour(tourId).getId()); OptionalDouble average = ratings.stream().mapToInt((rating) -> rating.getScore()).average(); return average.isPresent() ? average.getAsDouble():null; } /** * Service for many customers to give the same score for a service * @param tourId * @param score * @param customers */ public void rateMany(int tourId, int score, Integer [] customers) { tourRepository.findById(tourId).ifPresent(tour -> { for (Integer c : customers) { tourRatingRepository.save(new TourRating(tour, c, score)); } }); } /** * Verify and return the Tour given a tourId. * * @param tourId * @return the found Tour * @throws NoSuchElementException if no Tour found. */ private Tour verifyTour(int tourId) throws NoSuchElementException { return tourRepository.findById(tourId).orElseThrow(() -> new NoSuchElementException("Tour does not exist " + tourId) ); } /** * Verify and return the TourRating for a particular tourId and Customer * @param tourId * @param customerId * @return the found TourRating * @throws NoSuchElementException if no TourRating found */ private TourRating verifyTourRating(int tourId, int customerId) throws NoSuchElementException { return tourRatingRepository.findByTourIdAndCustomerId(tourId, customerId).orElseThrow(() -> new NoSuchElementException("Tour-Rating pair for request(" + tourId + " for customer" + customerId)); } }
标签:tourId,Java,business,Spring,NoSuchElementException,param,Tour,score,throws 来源: https://www.cnblogs.com/Answer1215/p/14176503.html