使用 Jersey 客户端发送多部分/混合请求

Question

I want to dialogue with this API service programmatically using Jersey ( https://eclipse-ee4j.github.io/jersey/ )

here's the Rest Controller implementation in Spring:

@PostMapping(
      value = "/api/my-endpoint",
      consumes = MediaType.MULTIPART_MIXED_VALUE)
  public void enrichInvoice(@RequestPart("metadata") Map<String, Object> request,
      @RequestPart("human") MultipartFile humanFile) {
    log.info(String.format("received request:%n%s", request));
  }

my client implementation would be like this

...
     final Client client = ClientBuilder.newClient(new ClientConfig()
          .register(MultiPartFeature.class)
          .register(JacksonFeature.class)
      );

      final FileDataBodyPart filePart = new FileDataBodyPart("human",myFile()));

      final BodyPart metadata = new BodyPart().entity(voBuilder.generateMetadata());

      final MultiPart multiPartEntity = new MultiPart();
      multiPartEntity.bodyPart(metadata, MediaType.APPLICATION_JSON_TYPE);
      multiPartEntity.bodyPart(filePart);

      final WebTarget target = client
          .target("http://localhost:8080/api/my-endpoint");
      final Entity<MultiPart> entity = Entity
          .entity(multiPartEntity, multiPartEntity.getMediaType());
      log.info(entity.toString());
      final Response response = target
          .request()
          .post(entity);
      log.info(String.format("%s", response.readEntity(String.class)));
      response.close();
...

But i keep getting this error:

Resolved [org.springframework.web.multipart.support.MissingServletRequestPartException: Required request part 'metadata' is not present]

which is because the metadata part has to be named "metadata". and I cannot find a way to name it using BodyPart. I also tried using FormDataBodyPart to build the metadata

FormDataBodyPart metadataBodyPart = new FormDataBodyPart("metadata", metadata,
          MediaType.APPLICATION_JSON_TYPE);

but with the same result.

Can you help me figure out what am I missing in the bodyPart definition?

Thanks

---

EDIT: here's the http request sent from my client implementation

Content-Type: multipart/mixed;boundary=Boundary_1_1972899462_1597045386454
User-Agent: Jersey/2.29 (HttpUrlConnection 11.0.8)
MIME-Version: 1.0
Host: localhost:8080
Accept: text/html, image/gif, image/jpeg, *; q=.2, */*; q=.2
Connection: keep-alive
Content-Length: 765

--Boundary_1_1972899462_1597045386454
Content-Type: application/json

{"value":"key"}
--Boundary_1_1972899462_1597045386454
Content-Type: application/octet-stream
Content-Disposition: form-data; filename="file.zip"; modification-date="Wed, 05 Aug 2020 16:52:52 GMT"; size=0; name="human"


--Boundary_1_1972899462_1597045386454--
]

Answer 1

The solution, even if not optimal, was to treat the metadata as a text file

final Path tempFile = Files.createTempFile("prefix", "suffix");
File fileMetadata = Files.write(tempFile.toAbsolutePath(), JsonUtils.toString(metadata).getBytes());

final FileDataBodyPart metadataBodyPart = new FileDataBodyPart(
          "metadata",
          fileMetadata,
          MediaType.APPLICATION_JSON_TYPE);

final FileDataBodyPart human = new FileDataBodyPart("human", new File(humanReadableFile.getFileKey()));

try (final MultiPart multiPartEntity = new MultiPart()) {
        multiPartEntity.bodyPart(metadataBodyPart);
        multiPartEntity.bodyPart(human);

    final Response response = client
        .target("http://localhost:8080/api/my-endpoint")
        .request()
        .post(Entity.entity(multiPartEntity, multiPartEntity.getMediaType()));
    log.debug(String.valueOf(response.getStatus()));
    log.debug(response.readEntity(String.class));
}

In this way the request body has to parts named "metadata" and "human" as requested by the controller implementation and still maintain the multipart/mixed content-type.