spring - How test rest file upload service? -

i created simple rest service upload file (in spring web application), method looks below:

    @post     @path("/job/upload")     @consumes(mediatype.multipart_form_data)     @produces({ "application/json; charset=utf-8" })     public response upload(list<attachment> attachments) {          log.info("upload new picture to!");         // unimportant code  } 

i try test restclient - firefox plugin. when call rest service see : status code: 415 unsupported media type.

how can test it? can add sample file in restclient , how can it?