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ActionContextCleanUp
Under the framework's architecture, the standard filter-chain optionally starts with the ActionContextCleanUp
filter, followed by other desired filters. Lastly, the FilterDispatcher
handles the request, usually passing it on to the ActionMapper. The primary purpose of the ActionContextCleanUp is to provide SiteMesh integration. The clean-up filter tells the dispatcher filter exactly when to remove obsolete objects from the request. Otherwise, the ActionContext may be removed before the decorator attempts to access it.
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