The above is the working principle diagram of springMVC:
1. The client sends an http request to the web server , and the web server parses the http request. If it matches the request mapping path of DispatcherServlet (specified in web.xml), the web container forwards the request to DispatcherServlet .
2. After DipatcherServlet receives the request, it will find the handler ( Handler ) to process the request according to the requested information (including URL, Http method, request header and request parameter Cookie, etc.) and the configuration of HandlerMapping .
3-4. The DispatcherServlet finds the corresponding Handler according to HandlerMapping , and gives the processing right to the Handler (the Handler encapsulates the specific processing), and then the specific HandlerAdapter makes a specific call to the Handler .
5. Handler will return a ModelAndView() object to DispatcherServlet after data processing is completed .
6. The ModelAndView () returned by Handler is just a logical view and not a formal view. DispatcherSevlet converts the logical view into a real view through ViewResolver .
7. The Dispatcher parses the parameters in ModelAndView() through the model and finally displays the complete view and returns