public static Set<String> getServletUrlPatterns( Document webXml, String servletName )
    {
        return getUrlPatterns( "servlet", webXml, servletName );
    }
Retrieves all URL patterns that apply to a specific servlet.

@param webXml web.xml document, parsed as XML (cannot be null)
@param servletName The name of the servlet (cannot be null or empty).
@return A collection (possibly empty, but never null).
xmppserver/src/main/java/org/jivesoftware/util/WebXmlUtils.java