@has
The listFile processor does not accept an inbound connection. If you know the filename of the file being created and the path where that file is created, all you need is the FetchFile processor.
handleHTTPRequest ---> <flow to execute jar> --> updateAttribute (set path and filename attributes) --> FetchFile --> handleHttpRequest --> <rest of dataflow>
The handleHttpRequest processor does not return content. It simply returns a response code back to for the original request which has not yet been responded to. The only thing you have control over in the response is the status code sent and sending custom headers in the response.
Hope this helps,
Matt