Spring spring webflux Flux<Part>

When I send a multipart request using ApiPost to my Spring WebFlux endpoint, I'm getting an error indicating "Content type 'application/octet-stream' not supported".

Here's the relevant part of my controller:

@PostMapping(value = "upload",consumes = MediaType.MULTIPART_FORM_DATA_VALUE)
    public Mono<String> uploadFile(@RequestPart("metadata") FileDto fileDto,@RequestPart("files") Flux<Part> files) throws IOException {
        long start = System.currentTimeMillis();
        MultiValueMap<String, Object> formData = new LinkedMultiValueMap<>();
        Mono<String> mono = files.flatMap(file -> {
                    formData.add("files", file);
                    return Mono.empty();
                })
                .thenMany(
                        webClient.post()
                                .uri("http://localhost:8081/upload")
                                .contentType(MediaType.MULTIPART_FORM_DATA)
                                .body(BodyInserters.fromMultipartData(formData))
                                .retrieve()
                                .bodyToMono(String.class)
                )
                .last()
                .defaultIfEmpty("Files forwarded successfully.");
        System.out.println(System.currentTimeMillis()-start);
        return mono;
    }

error: 2023-10-24 14:49:05.525 WARN 27364 --- [nio-8082-exec-1] .w.s.m.s.DefaultHandlerExceptionResolver : Resolved [org.springframework.web.HttpMediaTypeNotSupportedException: Content type 'application/octet-stream' not supported]

I expect the endpoint to correctly receive the multipart request, process it, and forward the files to another service.

Comment From: livk-cloud

When I send a multipart request using ApiPost to my Spring WebFlux endpoint, I'm getting an error indicating "Content type 'application/octet-stream' not supported".

Here's the relevant part of my controller:

java @PostMapping(value = "upload",consumes = MediaType.MULTIPART_FORM_DATA_VALUE) public Mono<String> uploadFile(@RequestPart("metadata") FileDto fileDto,@RequestPart("files") Flux<Part> files) throws IOException { long start = System.currentTimeMillis(); MultiValueMap<String, Object> formData = new LinkedMultiValueMap<>(); Mono<String> mono = files.flatMap(file -> { formData.add("files", file); return Mono.empty(); }) .thenMany( webClient.post() .uri("http://localhost:8081/upload") .contentType(MediaType.MULTIPART_FORM_DATA) .body(BodyInserters.fromMultipartData(formData)) .retrieve() .bodyToMono(String.class) ) .last() .defaultIfEmpty("Files forwarded successfully."); System.out.println(System.currentTimeMillis()-start); return mono; }

error: 2023-10-24 14:49:05.525 WARN 27364 --- [nio-8082-exec-1] .w.s.m.s.DefaultHandlerExceptionResolver : Resolved [org.springframework.web.HttpMediaTypeNotSupportedException: Content type 'application/octet-stream' not supported]

I expect the endpoint to correctly receive the multipart request, process it, and forward the files to another service.

"metadata" uses @RequestPart, but the transmitted data is of type TEXT, As far as I know, such data should be used @RequestParam

Comment From: sdeleuze

Please provide a reproducer, either as an attached Maven/Gradle project or by sharing such project via a Git repository.

Comment From: wjzxc123

Please provide a reproducer, either as an attached Maven/Gradle project or by sharing such project via a Git repository.

you can use test.htttp

https://github.com/wjzxc123/web-flux-demo

Comment From: sdeleuze

As far as I can tell, WebFlux server is not used in the module A of the repro because both Spring MVC and Spring WebFlux are in the classpath, if you only put WebFlux in module A classpath, I guess @RequestPart("files") Flux<FilePart> files handling will work as expected (not tried).