Best practice for redirecting a page when a Session is expired.

[kay lin]

Hi all:
I have an ActionForm class, in it, I have a method that populates the drop down from the Session, and I have a validate() to validate the form of course. And if the user enters something wrong, the jsp be page will be reloaded with the error message

Now, my problem is if the Session is timed out, then when the user click the submit button on the form, the JSP page will be reloaded, with the error message. however, any contents in the drop down will be GONE because the session timed out. So for an end user who is not very technical, he/she cannot figure out exactly what went wrong because the error message displayed on the reloade JSP page is not really descriptive of the problems with the drop down.


idealy, I would like my ActionForm class to redirect to a "timeout.jsp" so to speak when the session is timed out, but I can't exactly do this through the validate() method can I?

how should I redirect my page when the session is timed out in Struts? what is the best practice in Struts?


If anyone can lend me a hand on this, I'd be really greatful.


Many thanks

[Marc Peabody]

There are three options that I know of.
1) Use filters (these are not Struts-specific).
2) Extend RequestProcessor class.
3) Use a superclass action to implement the filtering functionality.

You can search the web for the first two methods. The last one is rather complicated and I don't recommend it for you because you would have to refactor all of your Actions.

The first option is my recommendation because it does not cause you to change any of the already-existing code. A filter would just add another layer.

[Marc Peabody]

Now that I think of it, you should probably look into using Struts tokens, especially if your forms are stored in session scope.

[Nathan Hook]

I perfer to use filters here like Marc first suggested. If the session doesn't exist the forward the user to a session expired page.

Best of Luck,

Nate