You can use Code Tags around JSP and XML. They're not just for
Java!
I can't really tell for sure, but my suspicion is that you're deploying the webapp to the wrong place.
I'll assume you're using Tomcat, but the principles are the same for the other
JEE servers - you cannot just dump files into the TOMCAT_HOME/webapps directory and expect them to run.
Webapps are defined as WAR files. A WAR is a specific type of JAR (ZIP) archive with a specific structure, including the
/WEB-INF directory and its children. In many webapp servers, you don't actually need a WAR file, as long as you provide something that looks like what you'd get if you unzipped ("exploded") a WAR file.
So far, so good. But the other thing is that
webapp servers support running more than one webapp at a time.
That means that you have to have a mechanism for keeping them separate, since you'd get a real mess if you just jumbled them all together.
Actually, you need
two mechanisms. One for URLs, so you know which webapp to send a URL request to, and one for WARs to keep them distinct.
In the case of the WARs, you do that by filing them under the TOMCAT_HOME/webapps/ directory in a subdirectory with the same name as the WAR. For example:
TOMCAT_HOME/webapps//DemoMVC,
In the case of URLs, you have the webapp
context path. The context path is the part of the URL that indicates which webapp receives the request. It follows the servername/port part of the URL and precedes the webapo's local URL sub-path. By default, it will have the same name as the WAR for that webapp, so if I send a URL request to
http://localhost:8080/DemoMVC/add, the webapp server will look at the
TOMCAT_HOME/webapps/DemoMVC deployment description (originally
/WEB-INF/web.xml, but often now built from annotations).
I think that this is probably where your problem lies.