The document describes the Model-View-Controller (MVC) architecture pattern for web applications. It consists of three components: the Model manages and represents the application's data, the View displays the data to the user, and the Controller handles interactions between the Model and View. Many frameworks like Spring and Ruby on Rails have adopted MVC concepts. The document then provides a specific example of using the Spring MVC framework to build a web application with the MVC pattern.

1. MVC Architecture
Emily Bauman

2. Overview
MVC structure is a design pattern for web
applications, with three components:
● Model
● View
● Controller

3. Overview

4. Model
● Responsible for maintaining data
● Represents knowledge - can be a single
object or a structure of objects

5. View
● Responsible for displaying data to user
● Representation of the model
○ presentation filter
○ shows only chosen data to the user

6. Controller
● Controls interactions between model & view
● Link between user and system
● The “brains” of the application
● Controls data flow into the model and
updates the view when data changes

7. Simple Example
Model View Controller
HTML CSS Web Browser
● Bare text
● The content, knowledge
of a web page
● Styling
● The display of a web
page
● Brings it all together
● Displays the view with
the knowledge of the
model, allowing
interaction for the user

8. Why is it used?
● Isolates the business logic from the user
interface
● Allows the application to be skinnable
○ same data with changeable views

9. Frameworks
Many programming frameworks have adopted
MVC concepts, including:
● Spring
● Django
● Ruby on Rails
● Struts
● ASP.NET

10. Our project
● Spring Web MVC framework
○ DispatcherServlet
○ ModelAndView object
○ Annotations

11. DispatcherServlet
● Dispatches requests to controllers
● Integrated with Spring IoC container

12. Spring MVC

13. Our Structure
● Model: ModelAndView object
● View: JSP pages
● Controller: Spring MVC controller

14. Model: ModelAndView
● Used ModelAndView object as our model
● Spring MVC object: represents a model and
view returned by a handler
● Model is a map with <K,V>

15. View: JSP
● Used JSP pages as the view
● Calls in attributes of the model

16. Controller: Spring MVC
● Defined with @Controller annotation
● @RequestMapping annotation to map URLs
to particular handler methods

17. Spring MVC Example
@RequestMapping(value = "/approvetask", method = RequestMethod.POST)
public ModelAndView approveTask() {
ModelAndView model = new ModelAndView();
model.addObject("msg", "You have approved an employee task.");
model.setViewName("mytasks");
return model;
}

18. Spring MVC Example
<c:if test="${not empty msg}">
<div class="msg">${msg}</div>
</c:if>

19. Spring MVC Example
<bean class="org.springframework.web.servlet.view.InternalResourceViewResolver">
<property name="prefix">
<value>/WEB-INF/pages/</value>
</property>
<property name="suffix">
<value>.jsp</value>
</property>
</bean>

20. Resources
http://docs.spring.io/spring/docs/current/spring-framework-reference/html/mvc.html
http://docs.spring.io/spring/docs/current/javadoc-api/org/springframework/web/servlet/ModelAndView.html
https://spring.io/guides/gs/rest-service/