Streaming Data Using Netflix Feign

At work, we use the Netflix Feign Client to help with cross-service requests. However, I'm confused by my apparent inability to transfer data, especially given Netflix's famous business model for streaming video. I am clearly missing something.

To explain, let's say Service A

a Feign client is requesting Service B

for a data stream and Service B

sending a stream in response. At this point, the method execute()

in the front client is called:

@Override public Response execute(Request request, Options options) throws IOException {
  HttpURLConnection connection = convertAndSend(request, options);
  return convertResponse(connection);
}

HttpURLConnection convertAndSend(Request request, Options options) throws IOException {
  final HttpURLConnection connection = (HttpURLConnection) new URL(request.url()).openConnection();

  /** SNIP **/

  if (request.body() != null) {
    if (contentLength != null) {
      connection.setFixedLengthStreamingMode(contentLength);
    } else {
      connection.setChunkedStreamingMode(8196);
    }
    connection.setDoOutput(true);
    OutputStream out = connection.getOutputStream();
    if (gzipEncodedRequest) {
      out = new GZIPOutputStream(out);
    }
    try {
      out.write(request.body()); // PROBLEM
    } finally {
      try {
        out.close();
      } catch (IOException suppressed) {
      }
    }
  }
  return connection;
}

      

        
        
        
      

    

The line marked PROBLEM

confuses me.

• The object request
  
  doesn't even have any kind of stream to read, just byte[] body
  
  .
• At the original end, the entire body is written in at OutputStream
  
  once. Shouldn't this be the data instead?

for example

// pseudocode
try {
  location = 0
  bufferSize = 2048
  buffer = request.body().read(location, bufferSize)
  while(out.readyToRead() && buffer.length > 0) {
    out.write(buffer)
    location += bufferSize
    buffer = request.body().read(location, bufferSize)
  }
}

      

        
        
        
      

    

If there was a thread in the request, not just one byte[] body

, you could improve that even further to send data as it comes in.

I am very new to this area of ​​service architecture. What am I missing?