@Post("/multipartObject")
    public HttpResponse multipartObject(Multipart multipart) throws IOException {
        return HttpResponse.of(
                multipart.aggregate()
                         .thenApply(AggregatedMultipart::bodyParts)
                         .thenApply(aggregatedBodyParts ->
                                            aggregatedBodyParts.stream()
                                                               .map(AggregatedHttpObject::contentUtf8)
                                                               .collect(Collectors.toList()))
                         .thenApply(HttpResponse::ofJson)
        );
    }
Examples how to use {@link Param} with {@link File}.
examples/annotated-http-service/src/main/java/example/armeria/server/annotated/FileUploadService.java