Upgrade from an existing http(s) connection

[neoedmund]

Describe what you would like to know or do

I used this library a long time, by binding ws/wss server to a specified port.
But it takes another port, besides my own http(s) server.
Can I use in another usecase? Say in the normal http server, If I found 'Upgrade: websocket' in the http header, I can let this library to take over the following work?
If this library cannot , do anyone knows which other java websocket library can do this?
Thanks.

Describe the solution you'd considered

Additional context