interface Example {
  static Example createInstance() {
    return Feign.builder()
        .encoder(new FormEncoder(new GsonEncoder()))
        .target(Example.class, "https://anything.com");
  }

  @RequestLine("POST")
  @Headers("Content-Type: multipart/form-data")
  void uploadWithDto(@Param("dto") Dto dto, @Param("file") File file);

  record Dto(String word, int number) {}

  public static void main(String[] args) throws URISyntaxException {
    Example api = Example.createInstance();
    File file = new File(Thread.currentThread().getContextClassLoader().getResource("file.txt").toURI());
    api.uploadWithDto(new Dto("hello", 123), file);
  }
}

interface Example {
  static Example createInstance() {
    return Feign.builder()
        .encoder(new FormEncoder(new GsonEncoder()))
        .target(Example.class, "https://anything.com");
  }

  @RequestLine("POST")
  @Headers("Content-Type: multipart/form-data")
  void uploadWithDto(@Param("dto") String dto, @Param("file") File file);

  record Dto(String word, int number) {}

  public static void main(String[] args) throws URISyntaxException {
    Example api = Example.createInstance();
    File file =
        new File(Thread.currentThread().getContextClassLoader().getResource("file.txt").toURI());
    api.uploadWithDto(new Gson().toJson(new Dto("hello", 123)), file);
  }
}