In Spring MVC, the process of mapping an incoming HTTP request to a controller and then to a specific handler method involves several components working together within the Spring MVC framework. Here's a detailed explanation of the steps involved in this process:
DispatcherServlet
The entry point for any incoming HTTP request in a Spring MVC application is the DispatcherServlet. It acts as the front controller, centralizing request handling by delegating requests to other components within the framework. The DispatcherServlet is responsible for orchestrating the overall request processing workflow[2][3].
HandlerMapping
Once the DispatcherServlet receives an HTTP request, it consults one or more HandlerMapping beans to determine which controller should process the request. HandlerMapping is an interface that defines a mapping between requests and handler objects (controllers). Spring provides several implementations of this interface, such as RequestMappingHandlerMapping, which is the default in Spring MVC[2][3][18].
@RequestMapping and Other Annotations
The @RequestMapping annotation is used to map web requests onto specific handler methods within a controller. It can be applied at the class level to indicate a base URI for all methods within the controller, and at the method level to specify the endpoint for that particular method. The annotation can define various criteria such as the HTTP method (GET, POST, etc.), request parameters, headers, and media types to match specific requests[3][7][19].
Binding Request Parameters
When a match is found, the DispatcherServlet sends the request to the chosen controller method. The method may have parameters annotated with @RequestParam, @PathVariable, @RequestBody, or other annotations that allow the binding of request parameters, path variables, request body, etc., to method parameters. Spring automatically converts and binds incoming request data to the appropriate method parameters[2][3].
HandlerAdapter
To execute the chosen handler method, the DispatcherServlet uses a HandlerAdapter. This component adapts the generic DispatcherServlet to the specific controller method. The HandlerAdapter invokes the method and also deals with the return value, which can be a ModelAndView object, a ResponseEntity, or other types of return values[2][3].
View Resolution
If the handler method returns a view name, a ViewResolver will be used to map this logical view name to an actual view, such as a...
