[WW-1573] Handling of If-Modified-Since header for static content

• Type: Improvement
• Status: Closed
• Priority: Major
• Resolution: Fixed
• Affects Version/s: 2.0.1
• Fix Version/s: 2.0.2
• Component/s: Dispatch Filter
• Flags: Patch
• Assignee: Unassigned
• Reporter: Dariusz Wojtas
• Created: 24/Dec/06 22:40
• Updated: 28/Oct/12 22:08
• Resolved: 28/Dec/06 00:37

Description

The issue described here was first described in WW-1536, but I think it is something more 'standalone' and not only 'tabbed panel' specific.

The problem is that Struts2 currently does not behave correctly on requests of type 'If-Modified-Since' for static content.
I am using firefox 1.5 and 2.0 and when reloading pages with ajax scripts, the browser usually asks for the content again, but it also uses 'If-Modified-Since' header.
Struts dispatcher ignores this header and sends the full content again.
But these are often static scripts/images of size 100kB-500kB in total.

I am trying to 'split' the WW-1536 issue as I was the originator of the problem description on the mailing list.
I am attaching a patch (a bit improved version from the one in WW-1536) which works for me for about 3 weeks perfectly - using trung from struts2.
I have examined the headers/content exchanged between server and browser and it is really worth it.

It only changes single method in the FilterDispatcher, enables If-Modified-Since and fixes 2 other issues:
a) no more thread-unsafe formatter instances (class level formatter)
b) no more playing with GMT and other timezones - there were issues with calculations seen during debug and interaction with the browser

Issue Links

• incorporates: WW-1536 TabbedPanel improvements