java.lang.IllegalArgumentException: The servlets named [X] and [Y] are both mapped to the url-pattern [/url] which is not permitted

Question

I tried to add this servlet

package com.classmgt.servlet;

@WebServlet(\"/ControllerServlet\")
public class ControllerServlet extends HttpServlet {}
         


        

Answer 1

Caused by: java.lang.IllegalArgumentException: The servlets named [ControllerServlet] and [com.classmgt.servlet.ControllerServlet] are both mapped to the url-pattern [/ControllerServlet] which is not permitted

It seems that you have mixed @WebServlet annotation based and web.xml based configuration.

I doubt that you created a Servlet using the "Create Servlet" wizard which creates web.xml entry with url-pattern and then , added a @WebServlet annotation which duplicates anything you may put in the web.xml.

You should use the one or the other, not both. Remove the mapping from web.xml and go ahead with using only the @WebServlet annotation.

Read more: Servlet 3.0 Annotations and our Servlets wiki page.