JSP model 2 architecture question

[Kit Mendelson]

The project I am working on has implemented the JSP model 2 architecture
and we are now grappling with a vexing issue related to it.
We use a central "controller" servlet to handle all incoming
requests and route them to the appropriate JSP (using
RequestDispatcher.forward()) based on the session context and the form
data submitted with each request. (We are running on WebLogic Server 5.1
and using the WLS plug-in on the iPlanet Web Server)

However, this means that from the web server's (and browser's) point of
view, every page of our application has the same URI (e.g. "/XYZ").
The problem is that our web server log is used to generate
usage reports, but there's no page-level usage being recorded for the app.
since all entries in the log simply point to /XYZ.

We've looked at "URL re-writing" but that doesn't help since it relies
on embedding the re-written URL in the links in the page body and we
don't know the final destination of any given link until it's been
processed by the controller servlet. We need a way for a given JSP to
somehow "set" it's URI (e.g. "/XYZ?pageID=x.jsp") as part of the *response*
that's sent to the browser so that it can be tracked (if that's even
possible) at the web server. We haven't been able to find a solution
running general searches on the Web and were wondering if anybody here has
run into this issue, and if so what, if anything, you figured out to do
about it.

TIA
-Kit

[Ruchi Dhar]

Since forward is internal to the servlet engine the client doesn't know what
happened after the request. The webserver log doesn't tell you anything
regarding the forwards. The only way is before forwarding to any page log
into the logfile. Its again difficult to write into the same log where IIS
is wring the log because of the locks. You have to maintain your own logFile
for all the requests and even for the servlets etc and in this case before
forwarding to the jsp you can write log to the logFile.

"Kit Mendelson" <christopher_mendelson@fanniemae.com> wrote:
>
>The project I am working on has implemented the JSP model 2 architecture
>and we are now grappling with a vexing issue related to it.
>We use a central "controller" servlet to handle all incoming
>requests and route them to the appropriate JSP (using
>RequestDispatcher.forward()) based on the session context and the form
>data submitted with each request. (We are running on WebLogic Server 5.1
>and using the WLS plug-in on the iPlanet Web Server)
>
>However, this means that from the web server's (and browser's) point of
>view, every page of our application has the same URI (e.g. "/XYZ").
>The problem is that our web server log is used to generate
>usage reports, but there's no page-level usage being recorded for the app.
>since all entries in the log simply point to /XYZ.
>
>We've looked at "URL re-writing" but that doesn't help since it relies
>on embedding the re-written URL in the links in the page body and we
>don't know the final destination of any given link until it's been
>processed by the controller servlet. We need a way for a given JSP to
>somehow "set" it's URI (e.g. "/XYZ?pageID=x.jsp") as part of the *response*
>that's sent to the browser so that it can be tracked (if that's even
>possible) at the web server. We haven't been able to find a solution
>running general searches on the Web and were wondering if anybody here has
>run into this issue, and if so what, if anything, you figured out to do

>about it.
>
>TIA
>-Kit

[Erik Pearson]

I'd suggest embedding information about intended target _context_ instead
of the actual destination page. After all, the destination is dynamic based
on incoming data, but the action taking place on the server to arrive at
the destination page is predictable as the action takes place. This context
informatoin could follow a similar paradigm as the Action or Command design
pattern in the famed GOF book. One would argue that this is more valid information
to capture than the resulting jsps anyways.

This information could easily be passed as path info so as to be indiscernable
from any web server logging requests before passing off to the application
server.

Examples:
/controller/changePrefs as opposed to /controller?pg=userPrefs.jsp
/controller/logout as opposed to /controller?pg=login.jsp
/controller/submitQuery as opposed to /controller?pg=queryResults.jsp

$0.02 -- Erik


"Kit Mendelson" <christopher_mendelson@fanniemae.com> wrote:
>
>The project I am working on has implemented the JSP model 2 architecture
>and we are now grappling with a vexing issue related to it.
>We use a central "controller" servlet to handle all incoming
>requests and route them to the appropriate JSP (using
>RequestDispatcher.forward()) based on the session context and the form
>data submitted with each request. (We are running on WebLogic Server 5.1
>and using the WLS plug-in on the iPlanet Web Server)
>
>However, this means that from the web server's (and browser's) point of
>view, every page of our application has the same URI (e.g. "/XYZ").
>The problem is that our web server log is used to generate
>usage reports, but there's no page-level usage being recorded for the app.
>since all entries in the log simply point to /XYZ.
>
>We've looked at "URL re-writing" but that doesn't help since it relies
>on embedding the re-written URL in the links in the page body and we
>don't know the final destination of any given link until it's been
>processed by the controller servlet. We need a way for a given JSP to
>somehow "set" it's URI (e.g. "/XYZ?pageID=x.jsp") as part of the *response*
>that's sent to the browser so that it can be tracked (if that's even
>possible) at the web server. We haven't been able to find a solution
>running general searches on the Web and were wondering if anybody here has
>run into this issue, and if so what, if anything, you figured out to do

>about it.
>
>TIA
>-Kit