Vinaya Tirikkovalluru schrieb: > > Hi, > > > > We have upgraded from Tomahawk 1.1.6 to Tomahawk 1.1.8 > > After this, we have been getting a lot of > javax.faces.application.ViewExpiredExceptions > > I was under the impression that > javax.faces.application.ViewExpiredException is caused only when the > session expires. > > Anybody else had this problem earlier? > > Could any one please tell me what are the other scenarios where this > is caused? > Firstly, note that this applies only when "server-side-state-saving" is enabled. A ViewExpiredException will never occur with "client-side-state-saving".
Myfaces keeps a cache of previous views in the session. At the start of each render phase, a new "view key" is allocated, and written into a hidden field in the html form. At the end of the render phase, the current view is stored into the cache using that key. On postback, if the "view key" specified by the posted form data does not match any entry in the cache, then a ViewExpiredException is reported. The cache has a fixed size, so that a user session does not grow continuously; when a view is stored into a full cache, the oldest entry is discarded. This allows a fixed-size number of "back button" clicks to work (the submitted form will contain an old "view key"). The actual number is configurable. Unfortunately this approach does not work too well if an application has multiple windows open; there is still just one cache, so if one window is used repeatedly then it will eventually push the saved view for other open windows out of the cache; then submitting the other window will cause a ViewExpiredException. Unfotunately http provides no way to know which window is which, so it is not possible to have a per-window cache. But all this view-cache-management is done by the jsf core implementation, *not* tomahawk. So I cannot think why upgrading Tomahawk is causing problems for you. Hopefully the above info will help you figure out what the actual problem is.. Regards, Simon -- -- Emails in "mixed" posting style will be ignored -- (http://en.wikipedia.org/wiki/Posting_style)
