The Session object can be used to:

The Connection State (is it open or not).

if(session.isOpen()) {
  // send message
}

Is the Connection Secure.

if(session.isSecure()) {
  // connection is using 'wss://'
}

What was in the Upgrade Request and Response.

UpgradeRequest req = session.getUpgradeRequest();
String channelName = req.getParameterMap().get("channelName");

UpgradeRespons resp = session.getUpgradeResponse();
String subprotocol = resp.getAcceptedSubProtocol();

What is the Local and Remote Address.

InetSocketAddress remoteAddr = session.getRemoteAddress();

Get and Set the Idle Timeout

session.setIdleTimeout(2000); // 2 second timeout