A URL pattern is a URL with special additions that maps to one or more resources. 
URL patterns are a convenient way to map security constraints to a collection of web resources.
When a URL pattern is used to subject security constraints on a collection of resources, any 
resource request that matches that URL pattern is subject to the security constraint. 
For example, if you define the URL pattern to be /salesinfo/*, all resources contained 
in salesinfo will be subject to the security constraint.