Sending multipart from Quarkus to Spring boot application

[jaakkouu]

Hey,

I opened up a question in Stackoverflow where brought into light how I do not understand the construction part of MultipartForm

@Data
@NoArgsConstructor
public class MyRequest {
  @FormParam("name")
  @PartType(MediaType.TEXT_PLAIN)
  public String name;

  @FormParam("mimeType")
  @PartType(MediaType.TEXT_PLAIN)
  public String mimeType;

  @FormParam("content")
  @PartType(MediaType.APPLICATION_OCTET_STREAM)
  public byte[] content;
}

After initiating the request org.jbo.res.rea.cli.log.DefaultClientLogger logs such message:
POST http://api.service:8080/create Headers[Accept=application/json Trace-Id=traceId Authorization=Bearer Token Content-Type=multipart/form-data; boundary=595a37631607c32 transfer-encoding=chunked User-Agent=Resteasy Reactive Client], Body omitted

Here is one of the the Resteasy Reactive client interface that I use to contact api.service:

@POST
  @Path("/create")
  @Produces(MediaType.APPLICATION_JSON)
  @Consumes(MediaType.MULTIPART_FORM_DATA)
  Uni<MyResponse> createTask(
          @HeaderParam("Trace-Id") String tradeId,
          @MultipartForm MyRequest content
  );

Endpoint at http://api.service:8080/create expects @RequestParam("content") List<MultipartFile> content. POST request above completes successfully and I am able to download the file back using different endpoint. When I request the file back from api.service the headers include Content-Disposition header with value attachment;filename=content;preview-type=application/octet-stream which might indicate /create is only grabbing the @FormParam("content") and ditching the rest.

Spring boot application expects RequestParam("content") List<MultipartFile> content. How do I model my MyRequest in Quarkus so that Spring Boot understands it?

• Using Quarkus 2.9.2.final
• Resteasy Reactive Client

[jaakkouu]

If I add @PartFilename("partFilename.jpg") on top of the public byte[] content file is saved as partFilename.jpg with type of "application/octet-stream"

[jaakkouu]

It appears to be completely impossible to do it by just annotations. It is solely impossible due to the way MultipartForm handling is done in RestEasy Reactive. I found out that I have create web client using vertx. So I basically ditched the whole idea of using @MultipartForm and RestEasy Client in this particular context. I still use it in other places in my application.

I created new "client" by using import io.vertx.ext.web.client.WebClient WebClient.create(vertx) and using that client to define and shoot http request.

newClient.postAbs("/create")
 .as(BodyCodec.json(MyResponse.class))
 .putHeader(HttpHeaders.CONTENT_TYPE, MediaType.MULTIPART_FORM_DATA)
 .putHeaders(myHeaders)
 .sendMultipartForm(form)

This way I can actually defined each part in my form to be exactly what I want them to be. Here is the form that I pass to that function:

MultipartForm.create().binaryFileUpload("content", name, Buffer.buffer(stream.readAllBytes()), mime)

Now multipart form actually has correct information: attachment;filename=image.jpg;preview-type=image/jpg

[boekkooi-lengoo]

So for people who don't want to use vertx directly, there is a way to use a jakarta.ws.rs.client.ClientRequestFilter with HeaderParam and some reflection to resolve the issue.

In my case I solved using the following setup.

@RegisterRestClient()
@RegisterProvider(HackyHTTPServiceFilter.class)
public interface MyHTTPService {
    @POST
    @Path("/binary")
    String LaunchTransaction(@Nonnull @RestForm("Files") byte[] file,
                             @Nonnull @HeaderParam("FilesName") String fileName,
                             @Nonnull @HeaderParam("FilesMediaType") String mediaType);
}

import jakarta.ws.rs.client.ClientRequestContext;
import jakarta.ws.rs.client.ClientRequestFilter;
import jakarta.ws.rs.ext.Provider;
import org.jboss.resteasy.reactive.client.impl.multipart.QuarkusMultipartForm;
import org.jboss.resteasy.reactive.client.impl.multipart.QuarkusMultipartFormDataPart;

import java.lang.reflect.Field;

@Provider
public class AbbyHTTPServiceFilter implements ClientRequestFilter {
    private static final Field mediaTypeField;
    private static final Field filenameField;

    static {
        try {
            mediaTypeField = QuarkusMultipartFormDataPart.class.getDeclaredField("mediaType");
            mediaTypeField.setAccessible(true);
            filenameField = QuarkusMultipartFormDataPart.class.getDeclaredField("filename");
            filenameField.setAccessible(true);
        } catch (NoSuchFieldException e) {
            throw new RuntimeException(e);
        }
    }

    @Override
    public void filter(ClientRequestContext requestContext) {
        if (!(requestContext.getEntity() instanceof QuarkusMultipartForm form)) {
            return;
        }
        var headers = requestContext.getHeaders();

        for (QuarkusMultipartFormDataPart f : form) {
            String mediaTypeHeader = f.name() + "MediaType";
            if (headers.getFirst(mediaTypeHeader) instanceof String mediaType) {
                // Set mediaType
                try {
                    mediaTypeField.set(f, mediaType);
                } catch (IllegalAccessException e) {
                    throw new RuntimeException(e);
                }
                // Remove temp header
                headers.remove(mediaTypeHeader);
            }

            String filenameHeader = f.name() + "Name";
            if (headers.getFirst(filenameHeader) instanceof String filename) {
                // Set name
                try {
                    filenameField.set(f, filename);
                } catch (IllegalAccessException e) {
                    throw new RuntimeException(e);
                }
                // Remove temp header
                headers.remove(filenameHeader);
            }
        }
    }
}

It's not pretty but it seems to work.

[danilopiazza]

Another solution is to use Quarkus REST Client, programmatically building your multipart form with ClientMultipartForm.

Rest Client Interface

@POST
@Path("/create")
@Produces(MediaType.APPLICATION_JSON)
@Consumes(MediaType.MULTIPART_FORM_DATA)
Uni<MyResponse> createTask(
        @HeaderParam("Trace-Id") String tradeId,
        ClientMultipartForm form
);

Multipart Form Creation

ClientMultipartForm.create()
        .binaryFileUpload(
                "content", // part name
                "partFilename.jpg", // file name
                Buffer.buffer(new byte[] { -1, -40, -1, -32 }), // file content as a byte array
                "image/jpeg" // MIME type
        )
        .binaryFileUpload(
                "content",
                "anotherFilename.gif",
                Buffer.buffer("GIF89a".getBytes()),
                "image/gif"
        );

This should allow you to upload two files, along with their names and MIME types, to a Spring Boot application expecting a request body representable as @RequestParam("content") List<MultipartFile> content.

Form Data Encoding

Finally, to prevent Quarkus from encoding content as a nested form part with multipart/mixed MIME type, make sure to set the form data encoding mode property (see also #39751):

quarkus.rest-client.multipart-post-encoder-mode=HTML5