WTFIGO consists of a ServletFilter which adds diagnostic
information to the footer of each page as the
application runs. The Filter intercepts log messages,
redirects, and exceptions to provide more information.
WTFIGO also includes a Dashboard to view information
about components of the web application and a suite of
JSP tags that help diagnose runtime issues.
WTFIGO is installed as a Filter and a Servlet in your web application. The Filter intercepts every request to the server and can decorate the reponse page with diagnostic information. The Servlet provides an interface to control WTFIGO and view broader information.
WTFIGO will also use any trick in the book to get at diagnostic information. Depending on the configuration of your container and the libraries you have installed, WTFIGO may register itself as a log writer or other event listener.
WTFIGO can also be accessed through JSP tags or directly as a library of useful diagnostic logic.