Java Web Application CMS

I am a beginer of Java Web using Servlet and JSP. I want to build a newspapers website, there is one functions that I have no idea. The function is user give comment to a article, when they press button "submit", the comment will appear with user's name along with it. I read many documents and they said that I should use CMS to handle this but CMS is too abstract. Can show me where to begin with this function, give some link or tutorial about this function ?
Can I use Server/JSP to build this problems. Anyways, thank you very much