Servlet Second Program by using GenericServlet abstract class(Console based application)

Hey I am a Servlet student I have design this video to improve my skill as well as your!
Please give me any suggestion if any problem in this video
--------------------------------------------------------------------
****Programs
===============
===============
-------------------------------------------------------------------------------------------------------

public class BlueServlet extends GenericServlet
{
public void init(ServletConfig conf){
}

public void service(ServletRequest req, ServletResponse res){
}

public void destroy(){
}
};

=========
=========
(place this file into F:\Tomcat 9.0\webapps\firstEx\WEB-INF folder)
--------------------------------------------------------------------------------------------------------
(web-app)
(servlet)
(servlet-name)obj(/servlet-name)
(servlet-class)BlueServlet(/servlet-class)
(/servlet)

(servlet-mapping)
(servlet-name)obj(/servlet-name)
(url-pattern)/Second(/url-pattern)
(/servlet-mapping)
(/web-app)
======================================================
Cuase I can't use this symbol in description as per youtube rules
======================================================

url
-------
======================================================

Program surely will run

If any problem occurred during executing program please must be comment I try to resolve your problem
======================================================

Thank you :)
-------------------