Spring MVC

1
Spring MVC

• The Perfect Wheel?

2
What Is The Spring Framework?

• Spring is a non-invasive application development
  framework that aims to make the life easier for
  Java/J2EE developers, by
• Providing a DI (or IoC) container.
• Providing an AOP framework that delivers services
  such as declarative transaction management.
• Providing abstraction for more complicated (J2EE)
  services and APIs, which removes lot of
  boilerplate code.
• DI AOP Service Abstraction Power to the POJO

3
Modules Of The Spring Framework
4
Spring MVC At A Glance

• Springs own implementation of Web MVC (Model2)
• Integrates nicely with the middle-tier via DI
• The components of the web framework is loosely
  coupled
• Supports several view technologies
• JSP/Tiles, Velocity, FreeMarker
• Support integration with other MVC frameworks
• Struts, Tapestry, JavaServerFaces, WebWork
• Provides a JSP Tag Library

5
A Typical Life Of A Request
6
Creating A Spring MVC Application

• Add the Spring dispatcher servlet to the web.xml
• Configure additional bean definition files in
  web.xml
• Write Controller classes and configure them in a
  bean definition file, typically
  META-INF/ltapplgt-servlet.xml
• Configure view resolvers that map view names to
  to views (JSP, Velocity etc.)
• Write the JSPs or other views to render the UI.

7
The Spring MVC Example The Buzzword Application

• Keep track of a list of buzzwords
• The user may
• List all buzzwords,
• View details of a specific buzzword,
• Add a new buzzword, or
• Delete a buzzword
• A buzzword consists of
• A name/acronym
• A description

8
The DispatcherServlet

• In META-INF/web.xml
• ltservletgt
• ltservlet-namegtbuzzwordslt/servlet-namegt
• ltservlet-classgt
• org.springframework.web.servlet.DispatcherSe
  rvlet
• lt/servlet-classgt
• ltload-on-startupgt1lt/load-on-startupgt
• lt/servletgt
• ltlistenergt
• ltlistener-classgt
• org.springframework.web.context.ContextLoade
  rListener
• lt/listener-classgt
• lt/listenergt
• ltcontext-paramgt
• ltparam-namegtcontextConfigLocationlt/param-namegt
  
• ltparam-valuegt/WEB-INF/buzzwords-service.xmllt/p
  aram-valuegt
• lt/context-paramgt

9
The BuzzwordController Class

• public class BuzzwordsController implements
  Controller
• private BuzzwordService facade
• public void setFacade(BuzzwordService facade)
  
• this.facade facade
• public ModelAndView handleRequest(HttpServletReq
  uest request,
• 
  HttpServletResponse response)
• throws Exception
• return new ModelAndView("buzzwords",
  "buzzwordService", facade)

10
The BuzzwordController Config

• In META-INF/buzzwords-servlet.xml
• ltbean id"buzzwordsController
• class"BuzzwordsController"gt
• ltproperty name"facade"gt
• ltref bean"buzzwordService"/gt
• lt/propertygt
• lt/beangt

11
The SimpleUrlHandlerMapping

• In META-INF/buzzwords-servlet.xml
• ltbean id"urlMapping" class"SimpleUrlHandlerMappi
  ng"gt
• ltproperty name"mappings"gt
• ltpropsgt
• ltprop key"/buzzwords.htm"gt
• buzzwordsControllerlt/propgt
• ltprop key"/editBuzzword.htm"gt
• editBuzzwordControllerlt/propgt
• ltprop key"/newBuzzword.htm"gt
• editBuzzwordControllerlt/propgt
• ltprop key"/submitBuzzword.htm"gt
• submitBuzzwordFormControllerlt/propgt
• ltprop key"/deleteBuzzword.htm"gt
• deleteBuzzwordFormControllerlt/propgt
• lt/propsgt
• lt/propertygt
• lt/beangt

12
The InternalResourceViewResolver

• In META-INF/buzzwords-servlet.xml
• ltbean id"viewResolver"
• class"org.springframework...InternalResourceVie
  wResolver"gt
• ltproperty name"viewClass"gt
• ltvaluegtorg.springframework...JstlViewlt/valuegt
• lt/propertygt
• ltproperty name"prefix"gtltvaluegt/WEB-INF/jsp/lt/va
  luegtlt/propertygt
• ltproperty name"suffix"gtltvaluegt.jsplt/valuegtlt/pro
  pertygt
• lt/beangt

13
The buzzwords.jsp

• lthtmlgtltheadgtlttitlegtltcout value"Buzzwords"/gtlt/tit
  legtlt/headgt
• ltbodygt
• lth1gtltcout value"Buzzwords"/gtlt/h1gt
• ltcforEach items"buzzwordService.buzzwo
  rds" var"buzzword"gt
• lta href"editBuzzword.htm?buzzwordNameltc
  out value"buzzword.name"/gt"/gtltcout
  value"buzzword.name"/gt
• lta href"deleteBuzzword.htm?buzzwordNamelt
  cout value"buzzword.name"/gt"/gtltcout value"
  delete"/gt
• ltbr/gt
• lt/cforEachgt
• ltbr/gt
• lta href"newBuzzword.htm"gtAdd a new
  buzzwordlt/agt
• lt/bodygt
• lt/htmlgt

14
The Buzzword Application

• Demo Time!

15
Testing Your Web Application

• All parts of the web application can be tested in
  isolation without any container
• The Controller
• The Validator
• Any in-house developed HandlerMapping class
• Any in-house developed ViewResolver class

16
Errors Is Not An Option, It Comes With The
Software

• ltbean id"exceptionResolver" class..SimpleMappin
  gExceptionResolver"gt
• ltproperty name"exceptionMappings"gt
• ltpropsgt
• ltprop key"java.lang.RuntimeException"gtindex
  lt/propgt
• lt/propsgt
• lt/propertygt
• lt/beangt

17
So, What Do You Think About Spring MVC?