The HttpSession and ServletContext are hard to retrieve: Add argument types for @OnOpen, @OnMessage, @OnError, and @OnClose methods

[glassfishrobot]

The HTTP session (HttpSession) and application context (ServletContext) are hard to retrieve within a server endpoint right now. The HTTP session can only be retrieved as described in #218. The ServletContext can only be retrieved if the HTTP session exists and if it is HttpSession, and requires retrieving the HttpSession and calling its getServletContext method.

#217 and #218 describe enhancements to make retrieving the HTTP session and application context easier. However, there's an even easier approach that can be implemented.

@onopen, @OnMessage, @onerror, and @onclose methods can have several different types of arguments that the container automatically supplies, such as the Session and various @PathParam arguments, EndpointConfig for @onopen, CloseReason for @onclose, Throwable for @onerror, and various message objects for @OnMessage. I recommend adding the following valid method parameters for all four annotations:

• The application context for the deployed application (in a Servlet container, this is a javax.servlet.ServletContext parameter), never null.
• The HTTP session object linked to the handshake request for this Session (in a Servlet container, this is a javax.servlet.http.HttpSession parameter), null if no HTTP session existed for the handshake request.

This would make generically retrieving the application context (ServletContext) and HTTP session (HttpSession) much easier.

Affected Versions

[2.0]

[glassfishrobot]

@glassfishrobot Commented
Reported by beamerblvd

[glassfishrobot]

@glassfishrobot Commented
This issue was imported from java.net JIRA WEBSOCKET_SPEC-219

[glassfishrobot]

• Issue Imported From: https://github.com/javaee/websocket-spec/issues/219
• Original Issue Raised By:@glassfishrobot
• Original Issue Assigned To: @pavelbucek

[joakime]

I generally an OK with this proposal, but ONLY for @OnOpen, as HttpSession and ServletContext are not valid once the websocket has been upgraded past the HTTP layer (where both HttpSession and ServletContext reside)

[markt-asf]

See #238