Introduction and Workflow of Spring MVC

Introduction to Spring MVC

Spring provides Model-View-Controller (MVC) architecture, and components that can be used to develop flexible and loosely coupled web applications. It uses the features of Spring core features like IoC and DI.

• The Model encapsulates the application data and in general they will consist of POJOs.

• The View is responsible for rendering the model data and in general it generates HTML output that the client’s browser can interpret.

• The Controller is responsible for processing user requests and building an appropriate model and passes it to the view for rendering.

---

Spring MVC Workflow

The Spring Web MVC framework is designed around the DispatcherServlet.

Java Servlet are programs that act as a middle layer between a request coming from a Web browser or HTTP client, and applications on the HTTP server.

What happens behind the scene when an HTTP request is sent to the server

• The DispatcherServlet handles all the HTTP requests and responses.

• After receiving an HTTP request, the DispatcherServlet consults the HandlerMapping to call the appropriate Controller.

• The Controller takes the request, calls the appropriate method, and builds the model and returns the view page name to the DispatcherServlet.

• The DispatcherServlet will then take help from the ViewResolver to pick up the defined view page for the request.

• Once the view is finalized, the DispatcherServlet passes the model data to the view, which is finally rendered on the browser.

All the above-mentioned components (i.e. HandlerMapping, Controller, and ViewResolver) are parts of WebApplicationContext, which is an extension of the ApplicationContext with some extra features necessary for web applications.