![Bean Validation Configuration Load validation XML configuration file [1] Create a bean validator [2] <bean id = "configurationLoader" class = "DefaultXmlBeanValidationConfigurationLoader" > <property name = "resource" value = "WEB-INF/validation.xml" /> </bean> <bean id = "beanValidator" class = "org.springmodules.validation.bean.BeanValidator" > <property name = "configurationLoader" ref = "configurationLoader" /> </bean> 1 2](https://image.slidesharecdn.com/springmvc-1216326324027094-8/85/Spring-MVC-31-320.jpg)
![Client Side Validation Valang validator validation is defined in valang expression language <bean id = "clientSideValidator" class = "org.springmodules.validation.valang.ValangValidator" > <property name = "valang" > <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>](https://image.slidesharecdn.com/springmvc-1216326324027094-8/85/Spring-MVC-34-320.jpg)
Spring MVC
- 2. Spring MVC Dror Bereznitsky Senior Consultant and Architect, AlphaCSP It’s Time
- 3. Agenda Introduction Background Features Review Configuration View technology Page flow Table sorting Search results pagination Validation AJAX Error handling I18n Documentation Summary
- 4. 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
- 5. 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
- 6. Introduction:: More Key Features Strong REST foundations Data Binding Framework Validation Framework Internationalization Support Tag Library
- 7. 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
- 8. 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
- 9. Agenda Introduction Background Features Review Configuration View technology Page flow Table sorting Search results pagination Validation AJAX Error handling I18n Documentation Summary
- 10. 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
- 11. Background:: Request Handlers Incoming requests are dispatched to handlers There are potentially many handlers per Dispatcher Servlet Controllers are request handlers
- 12. 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
- 13. Background:: Request Lifecycle Copyright 2006, www.springframework.org Handler
- 14. Features Review Introduction Background Features Review Configuration View technology Page flow Table sorting Search results pagination Validation AJAX Error handling I18n Documentation Summary
- 15. 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
- 16. 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
- 17. Annotated Controllers Simple POJO – no need to extend any controller base class ! @Controller public class PhoneBookController { @RequestMapping ( value = "/phoneBook" , method = RequestMethod. GET ) protected ModelAndView setupForm() throws Exception { ModelAndView mv = new ModelAndView(); … return mv; } PhoneBookController.java
- 18. 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= "org.springframework.web.servlet.mvc.annotation.DefaultAnnotationHandlerMapping" /> <bean class= "org.springframework.web.servlet.mvc.annotation.AnnotationMethodHandlerAdapter" /> <context:component-scan base-package= "com.alphacsp.webFrameworksPlayoff " />
- 19. Supported out of the box: JSP / JSTL XML / XSLT Apache Velocity Freemarker Adobe PDF Microsoft Excel Jasper Reports Features:: View Technology
- 20. 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 = "org.springframework.web.servlet.view.InternalResourceViewResolver" > <property name = "viewClass" value = "org.springframework.web.servlet.view. JstlView “ /> <property name = "prefix" value = "/WEB-INF/views" /> <property name = "suffix" value = " . jsp" /> </bean>
- 21. Features:: Page Flow mv.setView( new RedirectView( "../phoneBook“ , true ));
- 22. 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 = "/phoneBook" , method = RequestMethod. GET ) protected ModelAndView setupForm() throws Exception { ModelAndView mv = new ModelAndView(); mv.addObject( "contacts" , Collections.<Contact>emptyList()); mv.addObject( "contact" , new Contact()); … } PhoneBookController.java
- 23. Page Flow – Step 1 Contd. DispatcherServlet PhoneBookController Handle GET /demo/phoneBook 1 InternalResource ViewResolver 2 phoneBook /WEB-INF/views/phoneBook.jsp phoneBook
- 24. 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 = "/phoneBook" , method = RequestMethod. GET ) protected ModelAndView setupForm() throws Exception { ModelAndView mv = new ModelAndView(); mv.setViewName( "phoneBook" ); return mv; @RequestMapping ( value = "/phoneBook" , method = RequestMethod. GET ) protected ModelAndView setupForm() throws Exception { return " phoneBook " ; }
- 25. Page Flow – Step 2 Contd. DispatcherServlet PhoneBookController Handle GET /demo/phoneBook 1 InternalResource ViewResolver 2 phoneBook /WEB-INF/views/phoneBook.jsp phoneBook
- 26. Features:: Sorting & Pagination Search results pagination Sorting by column
- 27. 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 = " http://displaytag.sf.net " prefix = " display " %> <display:table name = "contacts" class = "grid" id = "contacts" sort = "list" pagesize = "5" requestURI = "/demo/phoneBook/list" > <display:column property =" fullName" title = "Name" class = "grid" headerClass = "grid" sortable = "true" /> … </display:table> phoneBook.jsp
- 28. 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
- 29. Features:: Form Binding @ModelAttribute annotations Spring’s form tag library EL expressions for binding path <td class = "searchLabel" ><b><label for = "email" > Email </label></b></td> <td class = "search" > <form:input id = "email“ path = "email" tabindex = "2" /> </td> @RequestMapping ( value = "/phoneBook/list" ) protected ModelAndView onSubmit( @ModelAttribute ( "contact" ) Contact contact, BindingResult result)
- 30. 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
- 31. Bean Validation Configuration Load validation XML configuration file [1] Create a bean validator [2] <bean id = "configurationLoader" class = "DefaultXmlBeanValidationConfigurationLoader" > <property name = "resource" value = "WEB-INF/validation.xml" /> </bean> <bean id = "beanValidator" class = "org.springmodules.validation.bean.BeanValidator" > <property name = "configurationLoader" ref = "configurationLoader" /> </bean> 1 2
- 32. Bean Validation Configuration Contact email validation Bound to the domain model and not to a specific form Validation.xml <validation> <class name = "com.alphacsp.webFrameworksPlayoff . Contact " > <property name = "email" > <email message = "Please enter a valid email address" apply-if = "email IS NOT BLANK" /> </property> </class> </validation> Domain Model
- 33. Server Side Validations Validator is injected to the controller Reusing the binding errors object PhoneBookController.java @Autowired Validator validator; @RequestMapping ( value = "/phoneBook/list" ) protected ModelAndView onSubmit( @ModelAttribute ( "contact" ) Contact contact, BindingResult result) throws Exception { … validator.validate(contact, result); …
- 34. Client Side Validation Valang validator validation is defined in valang expression language <bean id = "clientSideValidator" class = "org.springmodules.validation.valang.ValangValidator" > <property name = "valang" > <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>
- 35. Client Side Validation Contd. Use Valang tag library to apply the valang validator at client side Validation expression is translated to JavaScript <script type = "text/javascript" id = "contactValangValidator" > 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 = "http://www.springmodules.org/tags/valang" prefix = "valang" %> <script type = "text/javascript" src = "/scripts/valang_codebase.js" ></script> <form:form method = "POST" action = "/demo/phoneBook/list" id = "contact" name = "contact" commandName = "contact" > <valang:validate commandName = "contact" />
- 36. 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
- 37. AJAX:: Configuration The department service Spring bean <dwr> <allow> <create creator = "spring" javascript = "DepartmentServiceFacade" > <param name = "beanName" value = "departmentServiceFacade" /> </create> </allow> </dwr> <bean id ="departmentServiceFacade" class = "com.alphacsp.webFrameworksPlayoff.service.impl. MockRemoteDepartmentServiceImpl“ /> Exposing it to JavaScript using DWR DWR.xml
- 38. AJAX:: Autocomplete Component <script type = "text/javascript" src = "/scripts/prototype/prototype.js" ></script> <script type = "text/javascript" src = "/scripts/script.aculo.us/controls.js" ></script> <script type = "text/javascript" src = "/scripts/autocomplete.js" ></script> <td class="search"> <form:input id = "department" path = "department" tabindex = "3" cssClass = "searchField" /> <div id = "departmentList" class = "auto_complete" ></div> <script type = "text/javascript" > new Autocompleter.DWR( 'department' , 'departmentList' , updateList, {valueSelector: nameValueSelector, partialChars: 0 }); </script> </td> phoneBook.jsp
- 39. 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
- 40. Features:: I18n LocaleResolver automatically resolve messages using the client's locale AcceptHeaderLocaleResolver CookieLocaleResolver SessionLocaleResolver LocaleChangeInterceptor change the locale in specific cases Reloadable resource bundles
- 41. Features:: Documentation Excellent reference documentation ! Books – mostly on the entire framework Code samples Many AppFuse QuickStart applications
- 42. Summary Introduction Background Features Review Configuration View technology Page flow Table sorting Search results pagination Validation AJAX Error handling I18n Documentation Summary
- 43. 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
- 44. 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
- 45. 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
- 46. 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
- 47. Thank You !