Spring MVC provides a lightweight framework for building web applications. It separates concerns into modules with distinct roles like controllers, models and views. This makes applications highly configurable, reusable and easy to test. The framework uses annotations and inversion of control for configuration which promotes loose coupling and rapid development. Core components include the DispatcherServlet, controllers, models and view resolvers.

2. Advantage
• Separate roles - The Spring MVC separates each role, where the model object, controller, command object,
view resolver, DispatcherServlet, validator, etc. can be fulfilled by a specialized object.
• Light-weight - It uses light-weight servlet container to develop and deploy your application.
• Powerful Configuration - It provides a robust configuration for both framework and application classes
that includes easy referencing across contexts, such as from web controllers to business objects and
validators.
• Rapid development - The Spring MVC facilitates fast and parallel development.
• Reusable business code - Instead of creating new objects, it allows us to use the existing business objects.
• Easy to test - In Spring, generally we create JavaBeans classes that enable you to inject test data using the
setter methods.
• Flexible Mapping - It provides the specific annotations that easily redirect the page.

3. Advantage(Components)
• Inversion Of Control (IOC): In Spring Framework, loose coupling is achieved using Inversion of Control.
The objects give their own dependencies instead of creating or looking for dependent objects.
• Aspect Oriented Programming (AOP): By separating application business logic from system services,
Spring Framework supports Aspect Oriented Programming and enables cohesive development.
• Container: Spring Framework creates and manages the life cycle and configuration of application objects.
• Transaction Management: For transaction management, Spring framework provides a generic abstraction
layer. It is not tied to J2EE environments and it can be used in container-less environments.
• JDBC Exception Handling: The JDBC abstraction layer of the Spring Framework offers an exception
hierarchy, which simplifies the error handling strategy.
• MVC Framework: Spring Framework is a MVC web application framework. This framework is configurable
via interfaces and accommodates multiple view technologies.

7. Spring MVC Taxonomy
 DispatcherServlet
 Spring provided front controller
 Controls request routing
 Controllers
 User created POJO
 Standard Spring beans
 View
 Responsible for rendering a response

8. Core MVC components
 ModelAndView
 stores model data
 associates a view to the request
 can be a view implementation or a logical name
 ViewResolver
 Used to map logical view names to view implementations
 HandlerMapping
 Used by DispatcherServlet to map requests to controllers

9. Dispatcher Servlet
• Used to handle all incoming requests and route them through Spring
• Uses customizable logic to determine which controllers should handle which
requests
• Forwards all responses to through view handlers to determine the correct
views to route responses
• Exposes all beans defined in Spring to controllers for dependency injection

10. Model
• A Model is used in Spring MVC to pass objects from the controller tier up
into the view
• A Model is really just a java.util.Map
• You can add attributes to a Model and they will be put on the request as
attributes and available in the applications PageContext .
• In Spring you can simply pass back a Map orone of two Spring specific
classes; ModelMap or Model

11. Spring Views
 Extensive Support
 JSP, Velocity, FreeMarker, JasperReporters
 PDF, Excel
 Views are mapped by ViewResolvers

12. Spring MVC Annotations
 @Controller
 Stereotype used to “Controller” of MVC
 Scanned for RequestMappings
 Convention over configuration
 @RequestMapping
 Annotates a handler method for a request
 Very flexible
 @RequestParam
 Annotates that a method parameter should be bound to a web request parameter
 @SessionAttributes
 Marks session attributes that a handler uses

13. Spring MVC Parameters
 Parameters can be
 Request / response / session
 WebRequest
 InputStream
 OutputStream
 @RequestParam etc..

14. Spring MVC Return Types
 Return types
 ModelAndView Object
 Model Object
 Map for exposing model
 View Object
 String which is a view name
 Void… if method wrote the response content directly

15. Handler Mappings
 DefaultAnnotationHandlerMapping
 annotation based - @Controller
 SimpleUrlHandlerMapping
 configuration based
 still works with annotations
 ControllerClassNameHandlerMapping
 UrlFileNameViewController
 views without a controller