Spring MVC Dror Bereznitsky Senior Consultant and Architect, AlphaCSP It’s Time

Agenda Introduction Background Features Review Configuration View technology Page flow Table sorting Search results pagination Validation AJAX Error handling I18n Documentation Summary

Introduction

Background

Features Review

Configuration

View technology

Page flow

Table sorting

Search results pagination

Validation

AJAX

Error handling

I18n

Documentation

Summary

Introduction Spring’s web framework Optional Spring framework component Integrated with the Spring IoC container Web MVC framework Request-driven action framework Designed around a central servlet Easy for Struts users to adopt

Spring’s web framework

Optional Spring framework component

Integrated with the Spring IoC container

Web MVC framework

Request-driven action framework

Designed around a central servlet

Easy for Struts users to adopt

Introduction:: Key Features Simple model Easy to get going - fast learning curve Designed for extension Smart extension points put you in control Strong integration Integrates popular view technologies A part of the Spring framework All artifacts are testable and benefit from dependency injection

Simple model

Easy to get going - fast learning curve

Designed for extension

Smart extension points put you in control

Strong integration

Integrates popular view technologies

A part of the Spring framework

All artifacts are testable and benefit from dependency injection

Introduction:: More Key Features Strong REST foundations Data Binding Framework Validation Framework Internationalization Support Tag Library

Strong REST foundations

Data Binding Framework

Validation Framework

Internationalization Support

Tag Library

Introduction:: Full Stack Framework? Spring MVC is not a full-stack web framework, but provide the foundations for such Spring MVC is not opinionated You use the pieces you need You adopt the pieces in piece-meal fashion

Spring MVC is not a full-stack web framework, but provide the foundations for such

Spring MVC is not opinionated

You use the pieces you need

You adopt the pieces in piece-meal fashion

Introduction:: Spring 2.5 Released November 2007 Simplified, annotation based model for developing Spring MVC applications Less XML than previous versions Focuses on ease of use smart defaults simplified programming model

Released November 2007

Simplified, annotation based model for developing Spring MVC applications

Less XML than previous versions

Focuses on

ease of use

smart defaults

simplified programming model

Agenda Introduction Background Features Review Configuration View technology Page flow Table sorting Search results pagination Validation AJAX Error handling I18n Documentation Summary

Introduction

Background

Features Review

Configuration

View technology

Page flow

Table sorting

Search results pagination

Validation

AJAX

Error handling

I18n

Documentation

Summary

Background:: Dispatcher Servlet Dispatcher Servlet - front controller that coordinates the processing of all requests Dispatches requests to handlers Issues appropriate responses to clients Analogous to a Struts Action Servlet Define one per logical web application

Dispatcher Servlet - front controller that coordinates the processing of all requests

Dispatches requests to handlers

Issues appropriate responses to clients

Analogous to a Struts Action Servlet

Define one per logical web application

Background:: Request Handlers Incoming requests are dispatched to handlers There are potentially many handlers per Dispatcher Servlet Controllers are request handlers

Incoming requests are dispatched to handlers

There are potentially many handlers per Dispatcher Servlet

Controllers are request handlers

Background:: ModelAndView Controllers return a result object called a ModelAndView Selects the view to render the response Contains the data needed for rendering Model = contract between the Controller and the View The same Controller often returns different ModelAndView objects To render different types of responses

Controllers return a result object called a ModelAndView

Selects the view to render the response

Contains the data needed for rendering

Model = contract between the Controller and the View

The same Controller often returns different ModelAndView objects

To render different types of responses

Background:: Request Lifecycle Copyright 2006, www.springframework.org Handler

Features Review Introduction Background Features Review Configuration View technology Page flow Table sorting Search results pagination Validation AJAX Error handling I18n Documentation Summary

Introduction

Background

Features Review

Configuration

View technology

Page flow

Table sorting

Search results pagination

Validation

AJAX

Error handling

I18n

Documentation

Summary

Features:: Configuration Old school Spring beans XML configuration Annotation based configuration for Controllers (v2.5) XML configuration is still required for more advanced features: interceptors, view resolver, etc. Not mandatory, everything can still be done with XML

Old school Spring beans XML configuration

Annotation based configuration for Controllers (v2.5)

XML configuration is still required for more advanced features: interceptors, view resolver, etc.

Not mandatory, everything can still be done with XML

Deploy a DispatcherServlet Minimal web deployment descriptor web.xml <servlet> <servlet-name> spring-mvc-demo </servlet-name> <servlet-class> org.springframework.web.servlet.DispatcherServlet </servlet-class> <init-param> <param-name> contextConfigLocation </param-name> <param-value> /WEB-INF/spring-mvc-demo-servlet.xml </param-value> </init-param> </servlet> Dispatcher servlet configuration

Minimal web deployment descriptor

Annotated Controllers Simple POJO – no need to extend any controller base class ! @Controller public class PhoneBookController { @RequestMapping ( value = &quot;/phoneBook&quot; , method = RequestMethod. GET ) protected ModelAndView setupForm() throws Exception { ModelAndView mv = new ModelAndView(); … return mv; } PhoneBookController.java

Simple POJO – no need to extend any controller base class !

Dispatcher Servlet Configuration /WEB-INF/spring-mvc-demo.xml Setting up the dispatcher for annotation support Actually done by default for DispatcherServlet Auto detection for @Controller annotated beans <bean class= &quot;org.springframework.web.servlet.mvc.annotation.DefaultAnnotationHandlerMapping&quot; /> <bean class= &quot;org.springframework.web.servlet.mvc.annotation.AnnotationMethodHandlerAdapter&quot; /> <context:component-scan base-package= &quot;com.alphacsp.webFrameworksPlayoff &quot; />

/WEB-INF/spring-mvc-demo.xml

Setting up the dispatcher for annotation support

Actually done by default for DispatcherServlet

Auto detection for @Controller annotated beans

Supported out of the box: JSP / JSTL XML / XSLT Apache Velocity Freemarker Adobe PDF Microsoft Excel Jasper Reports Features:: View Technology

Supported out of the box:

JSP / JSTL

XML / XSLT

Apache Velocity

Freemarker

Adobe PDF

Microsoft Excel

Jasper Reports

Configure the view technology View Resolvers Renders the model Decoupling the view technology JSTL view JSP + JSTL –native choice for Spring MVC Spring tag libraries <bean class = &quot;org.springframework.web.servlet.view.InternalResourceViewResolver&quot; > <property name = &quot;viewClass&quot; value = &quot;org.springframework.web.servlet.view. JstlView “ /> <property name = &quot;prefix&quot; value = &quot;/WEB-INF/views&quot; /> <property name = &quot;suffix&quot; value = &quot; . jsp&quot; /> </bean>

View Resolvers

Renders the model

Decoupling the view technology

JSTL view

JSP + JSTL –native choice for Spring MVC

Spring tag libraries

Features:: Page Flow mv.setView( new RedirectView( &quot;../phoneBook“ , true ));

Features:: Page Flow – Step 1 Mapping URLs to handler methods Method level annotations Can restrict to specific request method URL strings can be error prone ! @RequestMapping ( value = &quot;/phoneBook&quot; , method = RequestMethod. GET ) protected ModelAndView setupForm() throws Exception { ModelAndView mv = new ModelAndView(); mv.addObject( &quot;contacts&quot; , Collections.<Contact>emptyList()); mv.addObject( &quot;contact&quot; , new Contact()); … } PhoneBookController.java

Mapping URLs to handler methods

Method level annotations

Can restrict to specific request method

URL strings can be error prone !

Page Flow – Step 1 Contd. DispatcherServlet PhoneBookController Handle GET /demo/phoneBook 1 InternalResource ViewResolver 2 phoneBook /WEB-INF/views/phoneBook.jsp phoneBook

Page Flow – Step 2 Choosing the view to be rendered Set the ModelAndView view name Or just return a view name String PhoneBookController.java @RequestMapping ( value = &quot;/phoneBook&quot; , method = RequestMethod. GET ) protected ModelAndView setupForm() throws Exception { ModelAndView mv = new ModelAndView(); mv.setViewName( &quot;phoneBook&quot; ); return mv; @RequestMapping ( value = &quot;/phoneBook&quot; , method = RequestMethod. GET ) protected ModelAndView setupForm() throws Exception { return &quot; phoneBook &quot; ; }

Choosing the view to be rendered

Set the ModelAndView view name

Or just return a view name String

@RequestMapping ( value = &quot;/phoneBook&quot; , method = RequestMethod. GET )

protected ModelAndView setupForm() throws Exception {

ModelAndView mv = new ModelAndView();

mv.setViewName( &quot;phoneBook&quot; );

return mv;

Page Flow – Step 2 Contd. DispatcherServlet PhoneBookController Handle GET /demo/phoneBook 1 InternalResource ViewResolver 2 phoneBook /WEB-INF/views/phoneBook.jsp phoneBook

Features:: Sorting & Pagination Search results pagination Sorting by column

Features:: Table Sorting Used the display tag library Handles column display, sorting, paging, cropping, grouping, exporting, and more Supports internal and external sorting Sort only visible records or the entire list <%@ taglib uri = &quot; http://displaytag.sf.net &quot; prefix = &quot; display &quot; %> <display:table name = &quot;contacts&quot; class = &quot;grid&quot; id = &quot;contacts&quot; sort = &quot;list&quot; pagesize = &quot;5&quot; requestURI = &quot;/demo/phoneBook/list&quot; > <display:column property =&quot; fullName&quot; title = &quot;Name&quot; class = &quot;grid&quot; headerClass = &quot;grid&quot; sortable = &quot;true&quot; /> … </display:table> phoneBook.jsp

Used the display tag library

Handles column display, sorting, paging, cropping, grouping, exporting, and more

Supports internal and external sorting

Sort only visible records or the entire list

Features:: Search Results Pagination Used the display tag pagination support for the demo Supports internal and external pagination Adds pagination parameter to request Limited to HTTP GET

Used the display tag pagination support for the demo

Supports internal and external pagination

Adds pagination parameter to request

Limited to HTTP GET

Features:: Form Binding @ModelAttribute annotations Spring’s form tag library EL expressions for binding path <td class = &quot;searchLabel&quot; ><b><label for = &quot;email&quot; > Email </label></b></td> <td class = &quot;search&quot; > <form:input id = &quot;email“ path = &quot;email&quot; tabindex = &quot;2&quot; /> </td> @RequestMapping ( value = &quot;/phoneBook/list&quot; ) protected ModelAndView onSubmit( @ModelAttribute ( &quot;contact&quot; ) Contact contact, BindingResult result)

@ModelAttribute annotations

Spring’s form tag library

EL expressions for binding path

Features:: Validations Used Spring Modules bean validation framework for server side validation Clear separation of concerns Declarative validation as in commons-validation Supports Valang - extensible expression language for validation rules

Used Spring Modules bean validation framework for server side validation

Clear separation of concerns

Declarative validation as in commons-validation

Supports Valang - extensible expression language for validation rules

Bean Validation Configuration Load validation XML configuration file [1] Create a bean validator [2] <bean id = &quot;configurationLoader&quot; class = &quot;DefaultXmlBeanValidationConfigurationLoader&quot; > <property name = &quot;resource&quot; value = &quot;WEB-INF/validation.xml&quot; /> </bean> <bean id = &quot;beanValidator&quot; class = &quot;org.springmodules.validation.bean.BeanValidator&quot; > <property name = &quot;configurationLoader&quot; ref = &quot;configurationLoader&quot; /> </bean> 1 2

Load validation XML configuration file [1]

Create a bean validator [2]

Bean Validation Configuration Contact email validation Bound to the domain model and not to a specific form Validation.xml <validation> <class name = &quot;com.alphacsp.webFrameworksPlayoff . Contact &quot; > <property name = &quot;email&quot; > <email message = &quot;Please enter a valid email address&quot; apply-if = &quot;email IS NOT BLANK&quot; /> </property> </class> </validation> Domain Model

Contact email validation

Bound to the domain model and not to a specific form

Server Side Validations Validator is injected to the controller Reusing the binding errors object PhoneBookController.java @Autowired Validator validator; @RequestMapping ( value = &quot;/phoneBook/list&quot; ) protected ModelAndView onSubmit( @ModelAttribute ( &quot;contact&quot; ) Contact contact, BindingResult result) throws Exception { … validator.validate(contact, result); …

Validator is injected to the controller

Reusing the binding errors object

Client Side Validation Valang validator validation is defined in valang expression language <bean id = &quot;clientSideValidator&quot; class = &quot;org.springmodules.validation.valang.ValangValidator&quot; > <property name = &quot;valang&quot; > <value> <![CDATA[ { firstName : ? IS NOT BLANK OR department IS NOT BLANK OR email IS NOT BLANK : 'At least one field is required'} ]]> </value> </property> </bean>

Valang validator

validation is defined in valang expression language

Client Side Validation Contd. Use Valang tag library to apply the valang validator at client side Validation expression is translated to JavaScript <script type = &quot;text/javascript&quot; id = &quot;contactValangValidator&quot; > new ValangValidator( 'contact' , true,new Array( new ValangValidator.Rule(' firstName' , 'not implemented' , 'At least one field is required' , function () { return ((! this.isBlank((this.getPropertyValue( 'firstName' )), ( null ))) || (! this.isBlank((this.getPropertyValue( 'department' )), ( null )))) || (! this.isBlank((this.getPropertyValue( 'email' )), ( null )))}))) </script> phoneBook.jsp <%@ taglib uri = &quot;http://www.springmodules.org/tags/valang&quot; prefix = &quot;valang&quot; %> <script type = &quot;text/javascript&quot; src = &quot;/scripts/valang_codebase.js&quot; ></script> <form:form method = &quot;POST&quot; action = &quot;/demo/phoneBook/list&quot; id = &quot;contact&quot; name = &quot;contact&quot; commandName = &quot;contact&quot; > <valang:validate commandName = &quot;contact&quot; />

Use Valang tag library to apply the valang validator at client side

Validation expression is translated to JavaScript

Features:: AJAX No built in AJAX support DWR is unofficially recommended by Spring Used DWR to expose the department service to JavaScript Requires dealing for low-level AJAX DWR has simple integration with Spring Used script.aculo.us autocomplete component with DWR

No built in AJAX support

DWR is unofficially recommended by Spring

Used DWR to expose the department service to JavaScript

Requires dealing for low-level AJAX

DWR has simple integration with Spring

Used script.aculo.us autocomplete component with DWR

AJAX:: Configuration The department service Spring bean <dwr> <allow> <create creator = &quot;spring&quot; javascript = &quot;DepartmentServiceFacade&quot; > <param name = &quot;beanName&quot; value = &quot;departmentServiceFacade&quot; /> </create> </allow> </dwr> <bean id =&quot;departmentServiceFacade&quot; class = &quot;com.alphacsp.webFrameworksPlayoff.service.impl. MockRemoteDepartmentServiceImpl“ /> Exposing it to JavaScript using DWR DWR.xml

The department service Spring bean

Exposing it to JavaScript using DWR

AJAX:: Autocomplete Component <script type = &quot;text/javascript&quot; src = &quot;/scripts/prototype/prototype.js&quot; ></script> <script type = &quot;text/javascript&quot; src = &quot;/scripts/script.aculo.us/controls.js&quot; ></script> <script type = &quot;text/javascript&quot; src = &quot;/scripts/autocomplete.js&quot; ></script> <td class=&quot;search&quot;> <form:input id = &quot;department&quot; path = &quot;department&quot; tabindex = &quot;3&quot; cssClass = &quot;searchField&quot; /> <div id = &quot;departmentList&quot; class = &quot;auto_complete&quot; ></div> <script type = &quot;text/javascript&quot; > new Autocompleter.DWR( 'department' , 'departmentList' , updateList, {valueSelector: nameValueSelector, partialChars: 0 }); </script> </td> phoneBook.jsp

Features:: Error Handling HandlerExceptionResolvers - handle unexpected exceptions Programmatic exception handling Information about what handler was executing when the exception was thrown SimpleMappingExceptionResolver – map exception classes to views

HandlerExceptionResolvers - handle unexpected exceptions

Programmatic exception handling

Information about what handler was executing when the exception was thrown

SimpleMappingExceptionResolver – map exception classes to views

Features:: I18n LocaleResolver automatically resolve messages using the client's locale AcceptHeaderLocaleResolver CookieLocaleResolver SessionLocaleResolver LocaleChangeInterceptor change the locale in specific cases Reloadable resource bundles

LocaleResolver

automatically resolve messages using the client's locale

AcceptHeaderLocaleResolver

CookieLocaleResolver

SessionLocaleResolver

LocaleChangeInterceptor

change the locale in specific cases

Reloadable resource bundles

Features:: Documentation Excellent reference documentation ! Books – mostly on the entire framework Code samples Many AppFuse QuickStart applications

Excellent reference documentation !

Books – mostly on the entire framework

Code samples

Many AppFuse QuickStart applications

Summary Introduction Background Features Review Configuration View technology Page flow Table sorting Search results pagination Validation AJAX Error handling I18n Documentation Summary

Introduction

Background

Features Review

Configuration

View technology

Page flow

Table sorting

Search results pagination

Validation

AJAX

Error handling

I18n

Documentation

Summary

Summary:: Pros Pros: Highly flexible Strong REST foundations A wide choice of view technologies New annotation configuration, less XML, more defaults Integrates with many common web solutions Easy adoption for Struts 1 users

Pros:

Highly flexible

Strong REST foundations

A wide choice of view technologies

New annotation configuration, less XML, more defaults

Integrates with many common web solutions

Easy adoption for Struts 1 users

Summary:: Cons Cons: Model2 MVC forces you to build your application around request/response principles as dictated by HTTP This was done by design in Spring MVC Requires a lot of work in the presentation layer: JSP, Javascript, etc. No AJAX support out of the box No components support

Cons:

Model2 MVC forces you to build your application around request/response principles as dictated by HTTP

This was done by design in Spring MVC

Requires a lot of work in the presentation layer: JSP, Javascript, etc.

No AJAX support out of the box

No components support

Summary:: Roadmap Spring 3.0 – August/September 2008 Unification in the programming model between Spring Web Flow and Spring MVC SpringFaces - JSF Integration Spring JavaScript - abstraction over common JavaScript toolkits AJAX support Conversational state

Spring 3.0 – August/September 2008

Unification in the programming model between Spring Web Flow and Spring MVC

SpringFaces - JSF Integration

Spring JavaScript - abstraction over common JavaScript toolkits

AJAX support

Conversational state

Summary:: References http://springframework.org/ Spring Source Spring Modules Spring IDE Appfuse light - spring MVC quickstarts Matt Raible - Spring MVC Expert Spring MVC and Web Flow

http://springframework.org/

Spring Source

Spring Modules

Spring IDE

Appfuse light - spring MVC quickstarts

Matt Raible - Spring MVC

Expert Spring MVC and Web Flow

Thank You !

Thank

You !