The dispatcher servlet
In the first chapter, we were introduced to the dispatcher servlet and saw how to define a dispatcher servlet in web.xml. We learned that every web request first comes to the dispatcher servlet. The dispatcher servlet is the one that decides the controller method that it should dispatch the web request to. In the previous chapter, we created a welcome page that will be shown whenever we enter the URL http://localhost:8080/webstore/ on the browser. Mapping a URL to the appropriate controller method is the primary duty of a dispatcher servlet.
So the dispatcher servlet reads the web request URL and finds the appropriate controller method that can serve that web request and invokes it. This process of mapping a web request to a specific controller method is called request mapping, and the dispatcher servlet is able to do this with the help of the @RequestMapping annotation (org.springframework.web.bind.annotation.RequestMapping).
