If HTTP request has content-type of "application/x-www-form-urlencoded" but with specified encoding (like "application/x-www-form-urlencoded; charset=UTF-8" then the POST parameters are not accessible using ServletRequest.getParameterNames/getParameter/etc. In other words, POST requests cannot be used in standard way in such a situation.

The bug is caused by implementation of ch.qos.logback.access.servlet.Util.isFormUrlEncoded. I attach a patch that solves the problem.