How to return an object from Mono SpringWebFlux more effective?

Question

I am using Spring Webflux, and I need to return the object of Author from Mono<Book>, But I don’t know how to do it more correctly.

The method that should return Author:

private Author getRegistredAuthor(Book bookInput) {
    String fullName = bookInput.getAuthor().getFullName();
    Optional<Author> optionalAuthor = repository.findByFullName(fullName).blockOptional();
    if(optionalAuthor.isPresent()){
        return optionalAuthor.get();
    }else {
        Author author = Author.builder().fullName(fullName).build();
        return repository.insert(author).block();
    }
}

The method that uses Author to create a new entity:

public Mono<BookDto> create(@RequestBody Book book) {
    book.setAuthor(getRegistredAuthor(book));
    return bookRepository.insert(book)
            .map(BookDto::of);
}

As I understand it, if I use block(), I will greatly reduce the effectiveness of reactive.

Will it be more effective if I use so ?

return repository.insert(author).blockOptional().get();

How would it be most efficient to return an object of Author?

Answer 1

As a result, I solved my problem using Mono.zip. Maybe my solution will help someone too:

    @PostMapping("/api/book")
    public Mono<BookDto> create(@RequestBody Book book) {
        return getObjectMono(book).flatMap(b -> bookRepository.insert(book))
                .map(BookDto::of);
    }


    private Mono<Object> getObjectMono(Book book) {
        return Mono.zip(
                getRegistredAuthor(book),
                getRegistredGenre(book)
        ).map(objects -> {
            book.setAuthor(objects.getT1());
            book.setGenre(objects.getT2());
            return book;
        });
    }

    private Mono<Genre> getRegistredGenre(Book bookInput) {
        String genreTitle = bookInput.getGenre().getTitle();
        return genreRepository.findByTitle(genreTitle)
                .switchIfEmpty(
                        genreRepository.insert(Genre.builder().title(genreTitle).build())
                );
    }

    private Mono<Author> getRegistredAuthor(Book bookInput) {
        String fullName = bookInput.getAuthor().getFullName();
        return authorRepository.findByFullName(fullName)
                .switchIfEmpty(
                        authorRepository.insert(Author.builder().fullName(fullName).build())
                );
    }