1. HandlerMapping processor mapping:
Through the processor mapping, the web request can be mapped to the correct processing controller. When the request is received, the dispatcherServlet will pass the request to the HandlerMapping processor mapping, let it check the request and find a suitable HandlerExecutionChain, this HandlerExecutionChain contains a processing The processor Controller of the request, and then the dispatcherServlet executes the processor Controller in the HandlerExecutionChain.
Spring has built-in many processor mapping strategies, such as SimpleUrlHandlermapping or BeanNameUrlHandlerMapping.
2. Controller processor:
Spring provides many powerful Controller implementations, which can inherit a suitable Controller to simplify the code.
3. ViewResolver view resolver:
Spring provides a view parser to be used in the browser to display the data model without being restricted to specific view technologies. Spring has built-in technologies such as jsp, Velocity, FreeMarker templates and XSLT views.