Internal helper class for some class management.
||A filter that does absolutely nothing.
||A reentrant mutual exclusion with the same basic
behavior and semantics as the implicit monitor lock accessed using
synchronized methods and statements.
||Provides the ability to test the url of a servlet-request against a set of criteria to determine
whether to "accept" the url or not.
||Compose two filter objects together, as if filter2 is nested within filter1.