Problem in displaying value from session object

[Yogendra Butola]

I working on attachment functionality on JSP page
Here are the steps I follow

1) On the jsp page I selects the file clicks the "Attach" link.
2) The request goes to a servlet which uploads the file to a directory.
3) The servlet shows the messgae "Your file has been uploaded", and a close button below that.
In the servlet I've set the filename in the session object.


4) When I click the "CLOSE" button, the servlet takes me back to the JSP page.
On the "CLOSE" button, I'm using "history.go(-1)", which will take me to the previous page

5) On the JSP page I'm displaying the name of the file, by retrieving from the HttpSession object.

However the file name dosen't get displayed.

When I click the browser's refresh button, the file name gets displayed

Please let me know why the JSP is not able to retrive the value from the session object.

Is it because I haven't submitted a new request.

[Ben Souther]

It sounds like you're seeing a cached version of the previous page when you click the back button.

Search this forum (and Google) with keywords 'pragma' and 'cache' for tips on preventing your browser from caching pages (browsers are not all compatible in this regard so you may need to suggest it in more than one way to achieve consistent results).

A better approach would be to use the post-redirect-get pattern to eliminate the need to duplicate the back button with Javascript.
After your upload, use response.sendRedirect to redirect the browser to your page. This will force a new request on the client side.