I am developing an OCCP -J 1.5/1.6/2.0 server. I played arround with different libs like Javalin, web container based websocket implementations - but I faced tons of problems due dependency problems in context with a Tomcat environment.

I found this libraray - but my first tries with an OCPP connections failed. Looking at the trace - the server communication failed because the OCPP protocol header were unkown for server - and no fallback was available.

Adding an own Draft to server solves this problem. But I would prefere that important detail is mentioned in the docu, Not everyone is using websockets for only HTTP relateted messages.