yes the Streaming socket is ´the right one for you.
You need a listener class like.
listenerSocket.createListener( 9090, String::empty);
StreamingSocket * newConnection = listenerSocket.waitForNextConnection();
The problem here.‘waitForNextConnection’ is blocking, so the best way is running in a worker thread.
and a new connection is signalled with callback, interfaces etc.
For the new connection you need a new class that handle all stuff for this new HTTP connection.
Here the same, create a thread and start the read function from the streaming socket. This is a blocking
call and for each successfully read, call a signal function for the incomming data to your HTTP server instance.
You write "the server on the ends is not a Juce App "., so I assume you need an DLL interface for the Juce stuff.