RE: About the Session ObjectRepository

Hi Ming,

First the brief answer...You will never need to call
setupSessionRepository...that happens behind the scenes for you already. So
all you have to do is check to see if the value exists in the session...if
it comes back null, that means it doesn't (ie. they are not logged on). So
as soon as they have sucessfully logged on, all you have to do is place the
value in their session (using the Session ObjectRepository), and then the
next time they request something, that value will be there.

Now some additional detail...The session repository is actually pretty
smart. You don't want to create a session for every single request that
comes in, otherwise someone could quickly run your webapp out of memory
simply by making a whole bunch of requests from different servers. So
really, we only want to create the session after we have verified that we
are dealing with a valid user. At the same time, we won't know if we're
dealing with a valid user until we check the session. Now, this sounds kind
of like a catch-22 situation, but its actually not. The session repository
effectively wraps the real http session, so that the real session does not
actually get created until we actually try and put something into it. In
other words, simply checking to see if the session holds a value will always
return false if the session does not yet exist. This keeps the overhead
minimal for bogus requests. The session only gets created when you actually
put a value into it (ie. because the user sucessfully logged on).

That make sense? Holler if you need further explanation!

Christian
----------------------------------------------
Christian Cryder
Internet Architect, ATMReports.com
Project Chair, BarracudaMVC - http://barracudamvc.org
----------------------------------------------
"Coffee? I could quit anytime, just not today"

  -----Original Message-----
  From: [email protected]
[mailto:[email protected]]On Behalf Of Ming Peng
  Sent: Friday, June 27, 2003 1:42 AM
  To: [email protected]
  Subject: [Barracuda] About the Session ObjectRepository


  Dear Sir
    I have a question on the "ObjectRepository".Sometimes,I want to check
whether the user ,who just made the request, has login in by the
HttpSession.If not,when I call the
"ObjectRepository.getSessionRepository()",what will I get?A "null"?And if I
want to setup a new session for a user,I must call the
"ObjectRepository.setupSessionRepository(HttpServletRequest req)"---is that
right?
    Sorry for my poor English.And thanks for your answer or any hints.