Expert Spring MVC and Web Flow

Figure 4-4.Sequence for HomeController

Summary

We have built, from the ground up, a Spring MVC application complete with a service layer

and an object model. Nearly all of the configuration work is complete as well, making it quite

easy to add functionality as the application grows.

You have been introduced to many of the core elements of a Spring MVC application,

including the Controller, ModelAndView, ViewResolver, View, and DispatcherServlet. The

Controllers and Views you will build and configure, while the ViewResolverand

DispatcherServlettypically require only configuration.

A Spring MVC application is initialized via the web.xmlfile, the standard configuration file

for a Java web application, but the configuration is performed via the bean definition XML

files such as applicationContext.xmland spring-servlet.xml. Both the DispatcherServlet

and the ContextLoaderListenerare defined in the web.xmlfile, providing the initialization and

bootstrap process for the entire Spring MVC application. Controllers and the ViewResolver

appear in spring-servlet.xml. The service layer and non–web-specific supporting services

appear in applicationContext.xml.

Having built a fully functional application, we will now implement the second use case.

The Search for Flights use case will be much simpler because we’ve completed the initial

configuration of the application. Its implementation will illustrate how Spring MVC handles

XHTML form processing.

64 CHAPTER 4 ■JUMP INTO SPRING MVC

DispatcherServlet HomeController

ModelAndView

Browser FlightService ViewResolver View

Return

an

existing

view

instance

2:handleRequest()

9:Resolve view

11:render()

3:getSpecialDeals()

5:new()

6:addObject( specialDeals )

8:Return ModelAndView

7:setView()

10:Return view

4:Return specialDeals

1:Request home

12:Return render to client