I see that you have a @HandlerChain annotation in your code - didn't handlers turn out to be a viable alternative. Handers is the first solution I would try.
Second, if handlers failed, I would consider a servlet filter for the servlet that receives the web service calls. Note that such a servlet filter would have to be configured to ONLY filter calls to the servlet receiving the web service calls and not the other servlet(s).
I'm THIS CLOSE to ruling the world! Right after reading this tiny ad: