Book service with caching

bookServiceCache.java

@Service
@Slf4j
public class BookService extends BaseService<Book> {

    private BookRepository repository;

    @Autowired
    public BookService(BookRepository repository) {
        this.repository = repository;
    }


    @Override
    public Mono<Book> findById(String bookId) {
        log.info("Requesting BOOK with id {}", bookId);
        List<String> cacheKeys = Collections.singletonList(bookId);

        return findCacheValue("OUR_CACHE", cacheKeys, repository.findFirstByBookId(bookId));


    }

 
    public Mono<Book> save(Book book) {
      return  Mono.just(book)
                    .flatMap(b -> repository.save(b))
                    .doOnNext(b -> writeCacheValue("OUR_CACHE", Collections.singletonList(b.getId()),b));
    }

    @Override
    public Mono<Book> update(String bookId, Book book) {
        return findById(bookId)
                .flatMap(b -> save(book));
    }

    @Override
    public Mono<Void> delete(String bookId) {
        return findById(bookId)
                .doOnNext(b -> evictValue("OUR_CACHE", Collections.singletonList(b.getId())))
                .flatMap(b -> {repository.delete(b); return Mono.empty();});
    }

}