@Api
@Path("/v1/multipart-request")
@Consumes(MediaType.MULTIPART_FORM_DATA)
public void doSomething(@MultiPartForm MyForm){
   ...
}

class MyForm {
  @FormParam("items")
  List<String> items;
}

------WebKitFormBoundary7MA4YWxkTrZu0gW
Content-Disposition: form-data; name="items[0]"

firstItem
------WebKitFormBoundary7MA4YWxkTrZu0gW
Content-Disposition: form-data; name="items[1]"

secondItem
------WebKitFormBoundary7MA4YWxkTrZu0gW