Browser back/forward button and Java Servlets

[John]

Hi everybody,
for my web-application (it must currently work only under IE6) I have
a servlet that intercepts user's HTTP GET requests for a typical
search result page, which contains a paging mechanismus for navigating
between the result pages (e.g. << 1 2 3 4 5 ... >).

When the user clicks on this navigation, the JSP send a GET request to
a servlet wich does some buisiness logic - in particular it logs (with
log4j) how many times an user navigates between the several pages and
then sends the response back to the client with the next search
results page. Everything works fine.

BUT if the user hits the browser's back/forward buttons, the servlet
which contains the counter for the log file will be never called from
the JSP, and so the counter will not increase its value for the log-
file.

I must handle this back/forward event (as well as, when the user
clicks the right mouse button to navigate the history - back or
forward).

I have no idea how to catch the event and calling the servlet for
incrementing the counter.... and the business sets me more and more
under pressure :-(

Does anybody has an idea, suggestion, or a link with an example?

Thank you very much for your suggestions :-)
John

[Joshua Cranmer]

John wrote:

Hi everybody,
for my web-application (it must currently work only under IE6) I have
a servlet that intercepts user's HTTP GET requests for a typical
search result page, which contains a paging mechanismus for navigating
between the result pages (e.g. << 1 2 3 4 5 ... >).

When the user clicks on this navigation, the JSP send a GET request to
a servlet wich does some buisiness logic - in particular it logs (with
log4j) how many times an user navigates between the several pages and
then sends the response back to the client with the next search
results page. Everything works fine.

BUT if the user hits the browser's back/forward buttons, the servlet
which contains the counter for the log file will be never called from
the JSP, and so the counter will not increase its value for the log-
file.

I must handle this back/forward event (as well as, when the user
clicks the right mouse button to navigate the history - back or
forward).

I have no idea how to catch the event and calling the servlet for
incrementing the counter.... and the business sets me more and more
under pressure :-(

Does anybody has an idea, suggestion, or a link with an example?

Thank you very much for your suggestions :-)
John

I'm guessing that what's going in is that the browser is loading a
cached back page, so it goes back to the cached page and sends no
request to the servlet. If this is the case, then sending a simple AJAX
request using a window.onload handler to get the servlet to recognize
the back should be sufficient.

[Randy Webb]

Joshua Cranmer said the following on 4/11/2007 10:43 PM:

John wrote:

>Hi everybody,
for my web-application (it must currently work only under IE6) I have
a servlet that intercepts user's HTTP GET requests for a typical
search result page, which contains a paging mechanismus for navigating
between the result pages (e.g. << 1 2 3 4 5 ... >).

When the user clicks on this navigation, the JSP send a GET request to
a servlet wich does some buisiness logic - in particular it logs (with
log4j) how many times an user navigates between the several pages and
then sends the response back to the client with the next search
results page. Everything works fine.

BUT if the user hits the browser's back/forward buttons, the servlet
which contains the counter for the log file will be never called from
the JSP, and so the counter will not increase its value for the log-
file.

I must handle this back/forward event (as well as, when the user
clicks the right mouse button to navigate the history - back or
forward).

I have no idea how to catch the event and calling the servlet for
incrementing the counter.... and the business sets me more and more
under pressure :-(

Does anybody has an idea, suggestion, or a link with an example?

Thank you very much for your suggestions :-)
John

I'm guessing that what's going in is that the browser is loading a
cached back page, so it goes back to the cached page and sends no
request to the servlet. If this is the case, then sending a simple AJAX
request using a window.onload handler to get the servlet to recognize
the back should be sufficient.

That won't work as the onload event isn't always fire when the page is
retrieved from the cache.

--
Randy
Chance Favors The Prepared Mind
comp.lang.javascript FAQ - http://jibbering.com/faq/index.html
Javascript Best Practices - http://www.JavascriptToolbox.com/bestpractices/

[Adam Maass]

"Joshua Cranmer" <Pi*******@epenguin.zzn.comwrote:

John wrote:

>Hi everybody,
for my web-application (it must currently work only under IE6) I have
a servlet that intercepts user's HTTP GET requests for a typical
search result page, which contains a paging mechanismus for navigating
between the result pages (e.g. << 1 2 3 4 5 ... >).

When the user clicks on this navigation, the JSP send a GET request to
a servlet wich does some buisiness logic - in particular it logs (with
log4j) how many times an user navigates between the several pages and
then sends the response back to the client with the next search
results page. Everything works fine.

BUT if the user hits the browser's back/forward buttons, the servlet
which contains the counter for the log file will be never called from
the JSP, and so the counter will not increase its value for the log-
file.

I must handle this back/forward event (as well as, when the user
clicks the right mouse button to navigate the history - back or
forward).

I have no idea how to catch the event and calling the servlet for
incrementing the counter.... and the business sets me more and more
under pressure :-(

Does anybody has an idea, suggestion, or a link with an example?

Thank you very much for your suggestions :-)
John

I'm guessing that what's going in is that the browser is loading a cached
back page, so it goes back to the cached page and sends no request to the
servlet. If this is the case, then sending a simple AJAX request using a
window.onload handler to get the servlet to recognize the back should be
sufficient.

Nocache HTTP response headers. I forget the exact format, but that should do
the trick.

[Sanjay]

Nocache HTTP response headers. I forget the exact format, but that
should do the trick.

If I remember correctly, this won't work in Firefox, as it has some kind
of cache (called back-forward cache?). Firefox caches pages even if you
set no-cache in http headers.