null Strings are converted to the empty string "".FilterDefinition instance represents a web.xml <filter> entry.FilterMappingDefinition represents the common portions of a web.xml <filter-mapping> entry.Set of dispatcher types for which the mapped filter
is enabled per the <dispatcher> elements in the definition's
configuration.FilterConfig
Concurrent SemanticsServletConfig
Concurrent SemanticsServletNameFilterMappingDefinition represents a web.xml <filter-mapping> entry,
which contains a <servlet-name element, and therefore maps the referenced filter to a particular
servlet.UrlPatternFilterMappingDefinition represents a web.xml <filter-mapping> entry
which contains a <url-pattern element, and therefore maps the referenced filter to a particular
URL pattern.