This week's book giveaway is in the Mac OS forum. We're giving away four copies of a choice of "Take Control of Upgrading to Yosemite" or "Take Control of Automating Your Mac" and have Joe Kissell on-line! See this thread for details.
You can't modify request parameters - what you have to do is make a custom HttpServletRequestWrapper extension. In your custom getParameter() and related methods, provide for catching the name of the parameter you want to "modify" In the filter, replace the original request with the wrapped request. Bill