How to up/download huge files with Feign?

I have to up/download huge files, bigger then fits into memory.
For the download I could use the Response object as it gives me the
(hopefully) unbuffered input stream. But how could I send big data
within a request.

I would like to avoid multipart files or similar. I would like to push the
binary data direct behind the request object.

Ideally, I would like to be able to stream data from a response object to a request object without
the need to write it into the file system.

Currently, I got stuck with the upload part. The encoder expects that I write the data either as string or byte[]
into the RequestTemplate. Is there no way to attach there an output stream?

Thanks,
Dieter

Start by tracing how RequestTemplate and the encoder currently accept String or byte[]; compare that with the Response object's input-stream path. Done means the requested upload and response-to-request streaming behavior works without buffering the data in memory or writing it to the filesystem.