On using servlet filters

Hi This query is in addition to a query I had posted some time before. When a document [of a particular type - which follows a particular template] is edited and submitted, or newly created, I want to log the IP address of the user plus some of the values of certain fields in that form. One reply I got was to use servlet filters? I tried using servlet filters and I found that it is possible. My doubts are : Is Servlet filters the preferred way for doing what I require in XWiki? Is there any other ways to do the same in xwiki? If Servlet filter is the way, then is there any preferred way to use in xwiki? (What I did was to place the servlets in WEB_INF/classes folder and added the entry in web.xml.) Regards Roopesh