How Spring MVC Works
How Spring MVC Works?
In this we will see the request flow for the spring framework. We
will also show you the request flow diagram illustrating the working of
Spring MVC module.
The Spring MVC modules comes with the Spring Framework distribution.
The Spring MVC modules of the Spring Framework well integrates with rest
of the framework. This modules is also very extensible.
Spring MVC is based on the MVC design pattern. Here is the list of
key classes of Spring MVC.
The DispatcherServlet is configured in the web.xml
file and required URL patterns are mapped to this
Servlet. It works as the front controller and handle all
the request from the user.
This class works as the holder for both Model and View
in the Spring MVC.
The SimpleFormController is the Concrete FormController
implementation. It provides the configurable form and
success views, and an onSubmit chain for convenient
overriding. Automatically resubmits to the form view in
case of validation errors, and renders the success view
in case of a valid submission.
Simplified Spring MVC architecture diagram
Following diagram shows the simplified architecture of Spring MVC:
Let's understand the sequences of the events happens when a request is received
by the Spring MVC. Following events happens when DispatcherServlet receives are
- The DispatcherServlet configured in web.xml
file receives the request.
- The DispatcherServlet finds the appropriate
Controller with the help of HandlerMapping and then
invokes associated Controller.
- Then the Controller executes the logic business
logic (if written by the programmer) and then returns
ModeAndView object to the DispatcherServlet.
- The DispatcherServlet determines the view from the
- Then the DispatcherServlet passes the model object
to the View.
- The View is rendered and the Dispatcher
Servlet sends the output to the Servlet container.
Finally Servlet Container sends the result back to the
Request flow in Spring MVC
Spring MVC is request driven and DispatcherServlet handles the
request from client and then dispatches the request to controllers. It
tightly integrates with the Spring IoC container and allows the
developers to use every features of Spring framework.
The following diagram illustrates the request flow in Spring MVC.
Request handling steps in Spring MVC
- Client access some URL on the server.
- The Spring Front Controller (DispatcherServlet)
intercepts the Request. After receiving the request it
finds the appropriate Handler Mappings.
- The Handle Mappings maps the client request to
appropriate Controller. In this process framework reads
the configuration information from the configuration
file or from the annotated controller list.
Then DispatcherServlet dispatch the request to the
appropriate Controller. The Handler Adapters involves in
- Then the Controller processes the Client Request, it
executes the logic defined in the Controller method and
finally returns the ModelAndView object back to the
- Based on the values in the ModelAndView Controller
resolves the actual view, which can be JSP, Velocity,
FreeMaker, Jasper or any other configured view resolver.
- Then the selected view is rendered and output is
generated in the form of HttpServletResponse. Finally
Controller sends the response to the Servlet container,
which sends the output to the user.
In the next section we will see the controller stack in Spring MVC