I have no doubt that when it comes time to make this webapp a full-fledged Internet capable application running on a production server that your superiors will be comforted by the fact that it runs in NetBeans.
No, I don't think they will. Just because something "works" doesn't mean it really works. That's why there's a published standard for JEE. I can name a number of things that "work" in Tomcat, but I'd fire people for doing them. Because they not only work despite being non-compliant with the standard, they also carry severe support costs.
If that is the sum total of your web.xml file, then I suspect you have annotated the servlet java code itself, thus causing 2 servlet definitions to be constructed, one for the web.xml and one based on the servlet annotations. Without seeing the servlet source, I can only suspect certain things, but at a minimum, it appears that you are in violation of package naming standards, as only the classname should carry an initial uppercase character. Package name components should begin with lower-case letters. I.e., refer.servlet.ResumeUpload.