Thanks ok I read the reference for Spring MVC.
So if I do not misunderstand the reference it means
1. you can suit in some way the workflow of the DispatcherServlet
namely when declaring some special beans used by that dispatcher
(showed in table 13.1.)
2. that you can nearly extend and suit everything in Spring MVC
from high till low level parts of Spring MVC because it is based
on interfaces what is very flexible and you can change the standard
implementation by referencing to your own implementation of that
interfaces (in the WebApplicationContext and ApplicationContext
or the web.xml).
Is it correct?