On Jun 18, 2009, at 9:51 AM, Adrian Crum wrote:
I created a simple WebDAV server to enable writable calendars in the
iCalendar integration. I'm finishing up the code and I have a few
outstanding issues to take care of.
I'm a little fuzzy on application servers and servlets, so I could
use some advice and guidance.
From what I understand, the container takes care of transactions, so
I shouldn't have to worry about transactions in my servlet code. Is
that correct?
Do you mean the Servlet container? If so no, the servlet stuff in
general doesn't know anything about or do anything with transactions
(unless there is some fancy new thing I'm not aware of). The OFBiz
framework does this at various points, which is probably what you're
used to. The main 2 places that OFBiz manages transactions are with
screen widget rendering, and with service engine calls. Even request
events in OFBiz don't automatically have transaction management, so if
you want transactions there (and you aren't calling a service) then
you have to write tx demarcation code (with the proper try/finally
stuff, etc... and OFTEN this is done incorrectly when it is done
manually like this).
WebDAV does not recognize sessions - no information is persisted
across requests. If that's the case, what would be a good strategy
for user log in/log out? To be more specific, a user updates their
calendar. A WebDAV request is made, the user is logged into OFBiz,
the work effort updates are made, and then...? If the user is logged
out afterwards, then that would also log them out of any browser
sessions they have going.
By "does not recognize sessions" do you mean that it doesn't/can't
pass around the jsessionid? In that case all it means is that each
request gets a new session, and that session is used only for that
request. The session will time out as normal, and will (hopefully!)
remain dormant as long as it is valid.
If there is no session passed and the requests run in their own
sessions, then it won't have an effect on other sessions even from the
same client. About the logout, if the user is explicitly logged out
then it will set the logged out flag in the database and that will
cause requests to existing sessions from that user to log them out. If
there is no explicit logout you don't have to worry about it. The
session will eventually expire and then the user is no longer "logged
in" as the session doesn't exist. If you are writing code to do this
manually, just remove the userLogin attribute from the session, or
even invalidate the session.
-David
