Understanding DispatcherHandler

DispatcherHandler, a front controller in Spring WebFlux, is what DispatcherServlet is in the Spring MVC framework. DispatcherHandler contains an algorithm that makes use of special components – HandlerMapping (maps requests to the handler), HandlerAdapter (a DispatcherHandler helper to invoke a handler mapped to a request), and HandlerResultHandler (a palindrome of words, for processing the result and forming results) – for processing requests. The DispatcherHandler component is identified by a bean named webHandler.

It processes requests in the following way:

1. A web request is received by DispatcherHandler.
2. DispatcherHandler uses HandlerMapping to find a matching handler for the request and uses the first match.
3. It then uses the respective HandlerAdapter to process the request, which exposes the HandlerResult (return value after processing). The return value could be one of the following – ResponseEntity, ServerResponse...