Java Mapping Web Client POST request to different objects without copy the code

Question

I have a post request which I want it to map the response to different objects for 2 api who call it. The request always return BookResponse.

Here I map the response to return the book name:

public Mono<String> getBookName(BookRequest bookRequest) {
  return client
            .post()
            .uri("PATH")
            .contentType(MediaType.APPLICATION_JSON)
            .accept(MediaType.APPLICATION_JSON_UTF8)
            .body(bookRequest))
            .retrieve()
            .bodyToMono(BookResponse.class)
            .doOnNext(this::validateResponseStatus)
            .map(BookResponse::getBookName)
            .doOnError(throwable -> logError(throwable));
 }

and here same call just map the response to other Object which contains the book author + the request object:

 public Mono<BookObject> getBookName(BookRequest bookRequest) {
        return client
            .post()
            .uri("PATH")
            .contentType(MediaType.APPLICATION_JSON)
            .accept(MediaType.APPLICATION_JSON_UTF8)
            .body(requestBody))
            .retrieve()
            .bodyToMono(BookResponse.class)
            .doOnNext(this::validateResponseStatus)
            .map(bookResponse -> new BookObject(bookResponse.getName(), bookRequest)
            .doOnError(throwable -> logError(throwable));

Is there a way to do it without copy the code? Thanks

Answer 1

I would extract the common code into a separate method:

public Something getSomething() {
  client
        .post()
        .uri("PATH")
        .contentType(MediaType.APPLICATION_JSON)
        .accept(MediaType.APPLICATION_JSON_UTF8)
        .body(requestBody))
        .retrieve()
        .bodyToMono(BookResponse.class)
        .doOnNext(this::validateResponseStatus)

}

Then, in your methods you simply need to do something like:

Something something = getSomething();
return something.map(bookResponse -> new BookObject(bookResponse.getName(), bookRequest).doOnError(throwable -> logError(throwable));

or

Something something = getSomething();
return something.map(BookResponse::getBookName).doOnError(throwable -> logError(throwable));