I don't think that the Tomcat default servlet has a namespace conflict with the webapp. In fact, I'm pretty sure that if a URL routing rule routed to a servlet whose logical name was "default" and there was no local (web.xml) pairing of that name with a class within the webapp's classpath it would result in an error. There's nothing I know of in the
J2EE standard that assures that there will be a servlet named "default" in every J2EE-compliant webapp server.
Tomcat's processing of URLs goes something like this:
First the URL is converted to server-local form so that the "http://hostname:port" part of the URL doesn't get considered as part of the matching process. So the matched path for "https://www.myserver.com/mywebapp/servlet1" would reduce to simply "/mywebapp/servlet1".
This normalized URL is then matched against the list of application contexts for deployed webapps in the server.
Then the URL under scan is further reduced to app-relative form. Meaning that "/mywebapp/servlet1" becomes "/servlet1".
This reduced URL is matched against the list of servlet URL
patterns provided in that webapp's WEB-INF/web.xml.
If the reduced URL matches one of the web.xml patterns, that pattern is used as the key to locate the servlet's logical name, which is in turn used to locate the servlet class instance based on its classname. At that point the URL request is handed over to the matched servlet.
In the event of no match, THEN Tomcat will attempt to find a
JSP whose resource path matches the reduced URL. If it finds one, the JSP will be compiled to create a servlet (or a previously-compiled copy will be located) and the URL request is sent there.
If neither webapp servlet pattern or JSP resource path match, then and only then will Tomcat attempt to process the request itself, using the master web.xml that's part of Tomcat itself (and which almost NEVER should be customized). The master web.xml will direct the unwanted URLs to Tomcat's internal default servlet, which will itself go through a set of attempts to resolve the URL, ending with the infamous "404" page, if nothing better can be done.
