You have learned that DispatcherServlet is the thing that dispatches the request to the handler methods based on the request mapping, but in order to interpret the mappings defined in a request mapping, DispatcherServlet needs a HandlerMapping (org.springframework.web.servlet.HandlerMapping) implementation. DispatcherServlet consults with one or more HandlerMapping implementations to know which handler can handle the request. So HandlerMapping determines which Controller to call.

HandlerMapping interface provides the abstraction for mapping requests to handlers. The HandlerMapping implementations are able to inspect the request and come up with an appropriate Controller. Spring MVC provides many HandlerMapping implementations, and the one we are using to detect and interpret mappings from the @RequestMapping annotation is the RequestMappingHandlerMapping (org.springframework.web.servlet.mvc.method.annotation. RequestMappingHandlerMapping) class. To start using RequestMappingHandlerMapping, we have to add the @EnableWebMvc annotation in our web application context configuration file, so that Spring MVC can create and register a bean for RequestMappingHandlerMapping in our web application context. If you remember, we already configured the @EnableWebMvc annotation in Chapter 2, Spring MVC Architecture – Architecting Your Web Store under the Understanding web application context configuration section.