Question

I have a Grails application that uses ThreadLocal.

Currently ThreadLocal populating and clearing is handled by a filter (before: populates, after: clears).

The problem is that the filter’s after-call is run before template is rendered so my needful variables are all nulls prematurely. Is there some simple way to trigger the clearing of ThreadLocals after the response is fully written?

One approach would be to clear the ThreadLocal before populating it, thus leaving all the work for filter’s before-call. But I don’t like the idea of leaving the ThreadLocal “carrying” the vars after they’re no longer used for anything so something else is needed.

Answer 1

after is called after the controller action finishes – you want the cleanup to be in afterView which is called after the view is rendered.