Using Struts to achieve asynchronous comms

[Gregory Polimis <gp...@algorithmics.com>]

Hello all. I've been wrestling with an asynchronous comms problem (for
almost a week) and am wondering if implementing struts can help.
I'm developing a web application that'll send a message to a server,
then wait for a response and display that response to a web browser (the
client). The problem is, the server requires an indeterminate
amount of time (from several seconds up to minutes, perhaps even hours
in production) so the servlet must 'wait' somehow until a response is
ready. Implementing blocking calls at the servlet level doean't seem
the way to go and I don't think a producer/consumer pattern will help
either.

Still searching the archives (my connection is unreliable today for some
reason) so my apologies if this has been dealt with already. Please
point me to the right resources if possible.  Thanks in advance for any
and all replies.

Greg

Re: Using Struts to achieve asynchronous comms

[Joe Peer <jo...@wap-force.net>]

hi,

maybe my approch is ridicolous but it would be very simple:

szenario:

1. your client request servlet url.
(your servlet stores the session id of your user (in any way) to remember 
him/her)
2. your servlets starts the process doing the heavy work (i suppose ;=)
3. your servlet sends *immediate* response, containing a html site with a 
meta refresh tag or some other code forcing the users browser to reload the 
site (== contact the servlet url), ie. every minute or so
4. every time the servlet gets contacted it checks if the working process 
is finished for the user. if not ready it sends the same html site again
5. finally if the user contacts the servlet again and if the result is 
available you redirect or forward him/her to the result page

this is how i would do it probable
joe

At 18:08 07.02.01, you wrote:
>Hello all. I've been wrestling with an asynchronous comms problem (for
>almost a week) and am wondering if implementing struts can help.
>I'm developing a web application that'll send a message to a server,
>then wait for a response and display that response to a web browser (the
>client). The problem is, the server requires an indeterminate
>amount of time (from several seconds up to minutes, perhaps even hours
>in production) so the servlet must 'wait' somehow until a response is
>ready. Implementing blocking calls at the servlet level doean't seem
>the way to go and I don't think a producer/consumer pattern will help
>either.
>
>Still searching the archives (my connection is unreliable today for some
>reason) so my apologies if this has been dealt with already. Please
>point me to the right resources if possible.  Thanks in advance for any
>and all replies.
>
>Greg