I was trying to obtain configuration information from the application web.xml file
The steps I followed as follows:-
created directory structure under C: in tomcat folder as-
web.xml This file is kept in my WEB-INF Folder)
The ConfigDemoServlet.java –(This is kept in classes folder under WEB-INF and has been compiled as well)
ALL classes used in servlets MUST be in packages and the class file in the corresponding directory. You got 404 because the container could not find the class file and the servlet never started. The full class name with package must appear in the servlet-class tag.