Proposal: tiny optional SSE client for HttpClient 5.6

[Arturo Bernal]

Hi all

Id like to propose adding a small, optional module that provides
Server-Sent Events (SSE) client support on top of CloseableHttpAsyncClient.
The goal is to keep core lean while offering a spec-compliant,
zero-dependency SSE layer that fits the HttpClient culture (tiny public
API, pluggable policies, strong tests, and clear docs).

What it is (very small API):


   -

   EventSource (start/cancel, headers, lastEventId, isConnected)
   -

   EventSourceListener (onEvent/onOpen/onClosed/onFailure)
   -

   EventSourceConfig with pluggable BackoffStrategy (we provide
   exponential-jitter, fixed, none)
   -

   SseExecutor (opens sources; uses existing client and works over HTTP/1.1
   or H2)


Feedback are welcome.


Thanks for considering!



Arturo