Thank you Greg for confirmation.
If you are able to find a reference to where this decision had been made
that would be very helpful!
Thanks,
Jozef
On 12/16/2014 03:56 PM, Greg Wilkins wrote:
>
> On 16 December 2014 at 10:19, Jozef Hartinger
> <jozefhartinger_at_gmail.com <mailto:jozefhartinger_at_gmail.com>> wrote:
>
> the behavior of *javax.servlet.ServletRequestListener* seems to be
> underspecified in Servlet 3.1 especially in case of asynchronous
> requests. I am seeking clarification for the case that follows.
>
>
> Jozef,
>
> A good summary of the issue. I'll have to search the archives but
> I do recall this being discussed before and it was decided that
> despite the names of the listener methods, they should be invoked as
> per your first example - specifically each time the servlet dispatches
> a thread to the context these listeners should be called.
>
> The reasoning for this comes from the ability to do cross context
> dispatches, both with synchronous and asynchronous APIs. Remember
> that the RequestListener is a artefact of each context. Consider a
> setup with 3 contexts, A, B & C and the following events take place:
>
> 1. request dispatched to context A
> 2. A RequestDispatcher.forward is used to invoke context B
> 3. startAsync is called on the request
> 4. the thread returns to the container.
> 5. an asynchronous thread calls AsyncContext.dispatch(ContextC,path)
> 6. the thread is dispatched to context C
> 7. the response is generated
> 8. the thread returns to the container.
>
> In this example, if each context has a request listener installed then
> calling order should be:
>
> * A.requestInitialized
> * B.requestInitialized
> * B.requestDestroyed
> * A.requestDestroyed
> * C.requestInitialized
> * C.requestDestroyed
>
> Again, we'll have to lookup the archives to see when/where this was
> decided, but I'm 99% sure that was the decision made. Obviously we
> have not documented that well enough, however I do note the javadoc on
> the listener:
>
> /**
> * Receives notification that a ServletRequest is
> * about to go out
> * of scope of the web application.
> *
> * @param sre the ServletRequestEvent containing
> * the ServletRequest
> * and the ServletContext representing the
> * web application
> */
> public void requestDestroyed(ServletRequestEvent sre);
>
> /**
> * Receives notification that a ServletRequest is
> * about to come
> * into scope of the web application.
> *
> * @param sre the ServletRequestEvent containing
> * the ServletRequest
> * and the ServletContext representing the web
> * application
> */
> public void requestInitialized(ServletRequestEvent sre);
>
> So note that it talks about entering and exiting the scope of the
> webapplication and not the initialization/destruction of the request
> objects.
>
> cheers
>
>
>
>
> --
> Greg Wilkins <gregw_at_intalio.com <mailto:gregw_at_intalio.com>> @ Webtide
> - /an Intalio subsidiary/
> http://eclipse.org/jetty HTTP, SPDY, Websocket server and client that
> scales
> http://www.webtide.com advice and support for jetty and cometd.