The method getParameterLogMap on com.opensymphony.xwork2.interceptor.ParametersInterceptor is declared as private. As a consequence it is not possible to override it.
The idea of overriding it is to be able to use log level DEBUG for that interceptor(and see the parameters on the log) while allowing some massaging of the log that will be shown. For example, I would like to show the value of any parameter, except for the one called password. As it is today, that is not possible.
The proposed solution is trivial: just change the method to be protected, so any user can override that method.