How to handle session variable when session times out

Hello all,

I am developing a web application where if the user's session times out, the next time he clicks on a link, he is redirected to the login page. After he logs in again, he is then taken to the page he was trying to access. The trouble is, I am storing some information in the session scope. For example, the user can view all the items he has created in the application. I store this list in the session. Now, suppose the user tries to view one of those items, but his session has timed out. So, he logs in again, but now his old session variables are gone, so when the login page forwards him to the page that should display the item details, the list is null, and I end up with a stack trace on the screen. What is the best way to handle this situation? Thank you for your help.

For more durable storage people commonly use a database - personally I like to have a custom object representing the user's current state and serialize that to a disk file.

Bill

Hi Bill,

Thanks for your reply. If you store session data in the database, don't you need a way to clear it out when the user's session ends? Would you run a job daily to clear out everything older than 24 hours, or something like that?

Treat the session like a cache. If the data is there, use it. If it isn't there, go and re-fetch it.

Thanks Bear!

I think stored this session in Cookies if the data no sensitive

You can also have some hidden field or cookie in your page which will contain the serialized & encrypted list or Object.
Otherwise if you are forced to keep that content on server, have a file (or database record) associated with the session, remove the file (or database record) when session is removed from server, have a mechanism to handle that file/record when you see an expired session, but this mechanism is having an issue... if the user wakes up too late when the session is removed, he wont be able to see that list.

One more suggestion is that you can keep last few records (or may be all the records as per your need) in database always associated with the user directly.