Explanation regarding Spring MVC flow
is asked during interview most of time to experience as well as fresher .so
here is the complete Spring MVC flow by which you can easily crack the
interview.
Spring MVC Flow
1. Browser gives request to Spring
MVC Web Application.
2. Dispatcher Servlet (sometimes called
Front controller ) takes and traps the request & applies the Common System
Services like Security, Logging, and Auditing.
3. Dispatcher Servlet delegates the
request to Handler Mapping.
4. Once handler mapping gets the request
maps the request with Handler Class/Controller class and returns the Handler Class Bean Id. Now dispatcher servlet
receives the bean id and somehow gets the handler class object and calls method
of that object so that control goes to handler class.
5. Handler class/Controller class
creates command class object and perform request wrapping .i.e. receives the
form data and stores (also called request wrapping) into Command Class object.
Actually command class is java bean whose object holds received the form data.( if there is form data).
6. Now handler class executes its own
business logic or talks with Service or DAO class get the output by
processing the request.
7. Now handler class returns Logical View
Name to dispatcher servlet.
8. Now dispatcher servlet take the
Logical view name and returns View Interface Implementation Class Object
having Physical View .it means dispatcher servlet uses View Resolver
to get View Object having view layer technology and resource.
9. Dispatcher servlet calls Render ()
method on that object.
10. Now Render () method ,
transfer the control to View Resource for getting physical view like
JSP, html etc.
11. JSP contains the presentation logic and format
the result and send formatted result to browser as response.
