How to upload multiple files using Webflux?

GVArt :

How to upload multiple files using Webflux?

I send request with content type: multipart/form-data and body contains one part which value is a set of files.

To process single file I do it as follow:

Mono<MultiValueMap<String, Part> body = request.body(toMultipartData());
body.flatMap(map -> FilePart part = (FilePart) map.toSingleValueMap().get("file"));

But how to done it for multiple files?

PS. Is there another way to upload a set of files in webflux ?

GVArt :

I already found some solutions. Let's suppose that we send an http POST request with an parameter files which contains our files.

Note responses are arbitrary

1. RestController with RequestPart

   @PostMapping("/upload")
   public Mono<String> process(@RequestPart("files") Flux<FilePart> filePartFlux) {
       return filePartFlux.flatMap(it -> it.transferTo(Paths.get("/tmp/" + it.filename())))
           .then(Mono.just("OK"));
   }
   

2. RestController with ModelAttribute

   @PostMapping("/upload-model")
   public Mono<String> processModel(@ModelAttribute Model model) {
       model.files.forEach(it -> it.transferTo(Paths.get("/tmp/" + it.filename())));
       return Mono.just("OK");
   }
   
   class Model {
       private List<FilePart> files;
       //getters and setters
   }
   

3. Functional way with HandlerFunction

   public Mono<ServerResponse> upload(ServerRequest request) {
       Mono<String> then = request.multipartData().map(it -> it.get("files"))
           .flatMapMany(Flux::fromIterable)
           .cast(FilePart.class)
           .flatMap(it -> it.transferTo(Paths.get("/tmp/" + it.filename())))
           .then(Mono.just("OK"));
   
       return ServerResponse.ok().body(then, String.class);
   }