Hi Musky,

Jean-Francois Arcand (Grizzly / Comet project lead) and myself have demo'ed a chat server application with Derby at ApacheCon US and JavaPolis.

We are working on a more generic framework that we intend to make available as part of some open source project (sub-project of Grizzly very likely). In the meantime, I'm going to post the source code and necessary archives on my blog. You can also find additional resources at:


You can check the slides we presented for more info, especially about Comet, if you're not familiar with it yet.

The idea behind this demo is to show the multi-tier aspect of Apache Derby. In this particular context, Derby is installed automatically and run (embedded) within the web browser as a Java plug-in extension. On this RIA client, Derby is used to store 'chat' conversation messages for any (signed-on) user that would use the chat application in that client. Messages are made persistent so that they can be re-read / re-accessed offline and you only get to see the messages for a particular user (obviously) - Messages could also be created offline so that the next time you're online, they get sent to the chat server. Derby runs embedded in the server to handle overflow of incoming and asynchronous messages, dispatched by Comet. Derby basically acts as an efficient and persistent cache to store data asynchronously, in this case, flux of incoming and outgoing network messages, handled by Comet.

I'll post back here when archives are available for download.



On Feb 13, 2008 7:05 AM, musky <muskvar@gmail.com> wrote:

i want to use derby as a chat server,
my idea is to insert whatever a user types into a table in the database.This
table can have two fields UserID and the message(VARCHAR).how do i convey
the inserted message to the other party??

please help.


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