Spring MVC is a request-based framework that uses a front controller servlet to delegate requests to action models based on the URL and parameters. It supports asynchronous requests using CallableController. Synchronous requests can be handled with @RestController. Views are rendered by preparing a model and returning a view path. Validation is done by a ValidateController. Custom exception handling is supported by @RestControllerAdvice and @ExceptionHandler. The configuration can be done in XML or Java code to map paths and add handlers.

1. Spring Web MVC
Hui Xie
Feb 2, 2019

2. Spring MVC
• git clone
git://github.com/SpringSource/spring-mvc-
showcase.git
• The following has been implemented in code.
– Ajax Controller
– Mapping Request
– Obtaining Request Data and Generating Response
– Rendering Views
– Validation
– Exception Handling

3. Spring MVC Overview

4. Framework Model
• Spring MVC is request based framework, which means a single front controller servlet will delegate
to action models based on request URL/params while in component based MVC, a single front
controller will gather, convert and validate request parameters or update the model values before
invoke the business action.
• Asyn request implementation of MVC model defines CallableController where a callable() method
is implemented to return data and throws a checked exception.
– In Asyn request, if it times out,
• Sync request implementation of MVC model can be achieved by defining a SimpleController using
@RestController annotation.
• When response data needs to be rendered, a ViewsController is defined to prepare the Model data
and return a path for viewed jsp. A view rendering will define the following classes for various
approach.
– DefaultRequestToViewNameTranslator convention
– Using path variables in a view template
– Data binding with URI variables
– HTML generated by JSP template

5. MVC Implementation
• In CallableController class, a few methods need to be implemented:
– callableWithException() with request parameters.
– handleException() intercepts ExceptionHandler.
• For controller specific exception handling, define ExceptionController as a type of RestController and
implement handle() method with input of specific exception.
• Custom exception handling can be implemented using @RestControllerAdvise and @ExceptionHandler
and implement handle%SpecificException, for example,
handleNotFoundException(CustomNotFoundException e) with ResponseMsg.
• Based on path patterns, request is mapped and produced in specific mediaType such as XML or JSON.
• Redirecting
– URL redirect allows one web page to be accessed via multiple links. It is needed for example, when a site needs to change its domain name or
two web sites might merge etc.
– The handler method in controller will redirect to a new URL.
• Configuration
– The servlet configuration can be done in xml with spring bean definitions or use java implementation to config path and add resources
handler, resolve views.
– During startup, the servlet container reads the configuration.
• Validation
– Upon the user clicks the viewed page, it triggers ValidateController, where validation method takes the JavaBean object and return the
binding result indicating error or no error.
•

6. References
• https://terasolunaorg.github.io/guideline/1.0.1.RELEASE/en/Overview/SpringMVCOverview.htm
• http://spring-bootstrap.herokuapp.com
• https://spring.io/blog/2013/11/01/exception-handling-in-spring-mvc