File Upload Using Feign – multipart/form-data

I’m trying to accomplish a multipart file upload using feign, but I can’t seem to find a good example of it anywhere. I essentially want the HTTP request to turn out similar to this:

...
Content-Type: multipart/form-data; boundary=AaB03x

--AaB03x
Content-Disposition: form-data; name="name"

Larry
--AaB03x
   Content-Disposition: form-data; name="file"; filename="file1.txt"
   Content-Type: text/plain

... contents of file1.txt ...
--AaB03x--

Or even…

------fGsKo01aQ1qXn2C
Content-Disposition: form-data; name="file"; filename="file.doc"
Content-Type: application/octet-stream

... binary data ...

------fGsKo01aQ1qXn2C--

Do I need to manually build the request body, including generating the multipart boundaries? That seems a bit excessive considering everything else this client can do.

Answer

No, you don’t. You just need to define a kind of proxy interface method, specify the content-type as: multipart/form-data and other info such as parameters required by the remote API. Here is an example:

public interface FileUploadResource {

    @RequestLine("POST /upload")
    @Headers("Content-Type: multipart/form-data")
    Response uploadFile(@Param("name") String name, @Param("file") File file);

} 

The completed example can be found here: File Uploading with Open Feign