groovy_web_workflow

Spring Web Flow是Spring家族中的一位成员，他能简化Web应用的开发。在Grails0.6中就集成了Spring Web Flow这一Web应用开发利器。下面通过一个实例向大家展示一下在Grails中如何方便的使用Spring Web Flow。

　　1，“grails create-app WebFlowDemo”，输出如下：

　　D:_DEVgrails_apps>grails create-app WebFlowDemo　　Welcome to Grails 0.6 - http://grails.org/　　Licensed under Apache Standard License 2.0　　Grails home is set to: D:DMY_DEVgrails0.6　　Base Directory: D:_DEVgrails_apps　　Environment set to development　　Note: No plugin scripts found　　Running script D:DMY_DEVgrails0.6scriptsCreateApp.groovy　　Overriding previous definition of reference to groovyJarSet　　[mkdir] Created dir:　　D:_DEVgrails_appsWebFlowDemosrc　　[mkdir] Created dir:　　D:_DEVgrails_appsWebFl　　owDemosrcjava　　[mkdir] Created dir:　　D:_DEVgrails_appsWebFlowDemosrcgroovy　　[mkdir] Created dir:　　D:_DEVgrails_appsWebFlowDemograils-app　　[mkdir] Created dir:　　D:_DEVgrails_appsWebFlowDemograils-appcontrollers　　[mkdir] Created dir:　　D:_DEVgrails_appsWebFlowDemograils-appservices　　[mkdir] Created dir:　　D:_DEVgrails_appsWebFlowDemograils-appdomain　　[mkdir] Created dir:　　D:_DEVgrails_appsWebFlowDemograils-app　　aglib　　[mkdir] Created dir:　　D:_DEVgrails_appsWebFlowDemograils-apputils　　[mkdir] Created dir:　　D:_DEVgrails_appsWebFlowDemograils-appviews　　[mkdir] Created dir:　　D:_DEVgrails_appsWebFlowDemograils-appviewslayouts　　[mkdir] Created dir:　　D:_DEVgrails_appsWebFlowDemograils-appi18n　　[mkdir] Created dir:　　D:_DEVgrails_appsWebFlowDemograils-appconf　　[mkdir] Created dir:　　D:_DEVgrails_appsWebFlowDemo　　est　　[mkdir] Created dir:　　D:_DEVgrails_appsWebFlowDemo　　estunit　　[mkdir] Created dir:　　D:_DEVgrails_appsWebFlowDemo　　estintegration　　[mkdir] Created dir:　　D:_DEVgrails_appsWebFlowDemoscripts　　[mkdir] Created dir:　　D:_DEVgrails_appsWebFlowDemoweb-app　　[mkdir] Created dir:　　D:_DEVgrails_appsWebFlowDemoweb-appjs　　[mkdir] Created dir:　　D:_DEVgrails_appsWebFlowDemoweb-appcss　　[mkdir] Created dir:　　D:_DEVgrails_appsWebFlowDemoweb-appimages　　[mkdir] Created dir:　　D:_DEVgrails_appsWebFlowDemoweb-appWEB-INFclasses　　[mkdir] Created dir:　　D:_DEVgrails_appsWebFlowDemoweb-appMETA-INF　　[mkdir] Created dir:　　D:_DEVgrails_appsWebFlowDemolib　　[mkdir] Created dir:　　D:_DEVgrails_appsWebFlowDemograils-appconfspring　　[mkdir] Created dir:　　D:_DEVgrails_appsWebFlowDemograils-appconfhibernate　　[propertyfile] Creating new property file:　　D:_DEVgrails_appsWebFlowDemoapplication.properties　　[copy] Copying 2 files to　　D:_DEVgrails_appsWebFlowDemo　　[copy] Copying 2 files to　　D:_DEVgrails_appsWebFlowDemoweb-appWEB-INF　　[copy] Copying 5 files to　　D:_DEVgrails_appsWebFlowDemoweb-appWEB-INF　　ld　　[copy] Copying 131 files to　　D:_DEVgrails_appsWebFlowDemoweb-app　　[copy] Copying 1 file to　　D:_DEVgrails_appsWebFlowDemograils-appconf　　[copy] Copying 13 files to　　D:_DEVgrails_appsWebFlowDemograils-app　　[copy] Copying 1 file to　　D:_DEVgrails_appsWebFlowDemograils-appconfspring　　[copy] Copying 1 file to　　D:_DEVgrails_appsWebFlowDemo　　[copy] Copying 1 file to　　D:_DEVgrails_appsWebFlowDemo　　[copy] Copying 1 file to　　D:_DEVgrails_appsWebFlowDemo　　[propertyfile] Updating property file:　　D:_DEVgrails_appsWebFlowDemoapplication.properties　　Created Grails Application at D:_DEVgrails_apps/WebFlowDemo　　D:_DEVgrails_apps>

　　2，“cd WebFlowDemo”，进入工程目录

　　3，“grails create-domain-class User”，创建一个域类User，输出如下

　　D:_DEVgrails_appsWebFlowDemo>grails create-domain-class User　　Welcome to Grails 0.6 - http://grails.org/　　Licensed under Apache Standard License 2.0　　Grails home is set to: D:DMY_DEVgrails0.6　　Base Directory: D:_DEVgrails_appsWebFlowDemo　　Environment set to development　　Note: No plugin scripts found　　Running script　　D:DMY_DEVgrails0.6scriptsCreateDomainClass.groovy　　[copy] Copying 1 file to　　D:_DEVgrails_appsWebFlowDemograils-appdomain　　Created　for User　　[copy] Copying 1 file to　　D:_DEVgrails_appsWebFlowDemo　　estintegration　　Created Tests for User　　D:_DEVgrails_appsWebFlowDemo>

　　4，将grails-appdomainUser.groovy修改为如下内容：

　　class　User　implements　Serializable {　　String username　　String password　　}

　　5，“grails generate-all User”，生成所有与域类User相关的目录和文件，输出如下

　　D:_DEVgrails_appsWebFlowDemo>grails generate-all User　　Welcome to Grails 0.6 - http://grails.org/　　Licensed under Apache Standard License 2.0　　Grails home is set to: D:DMY_DEVgrails0.6　　Base Directory: D:_DEVgrails_appsWebFlowDemo　　Environment set to development　　Note: No plugin scripts found　　Running script　　D:DMY_DEVgrails0.6scriptsGenerateAll.groovy　　[mkdir] Created dir:　　C:Documents and SettingsDaniel.grails.6projectsWebFlowDemoclasses　　Compiling 5 source files to　　C:Documents and SettingsDaniel.grails.6projectsWebFlowDemoclasses　　[mkdir] Created dir:　　D:_DEVgrails_appsWebFlowDemoweb-appWEB-INFgrails-appi18n　　[copy] Copying 8 files to　　D:_DEVgrails_appsWebFlowDemoweb-appWEB-INFgrails-appi18n　　[copy] Copying 1 file to　　D:_DEVgrails_appsWebFlowDemoweb-appWEB-INFspring　　[copy] Copying 1 file to　　C:Documents and SettingsDaniel.grails.6projectsWebFlowDemoclasses　　[copy] Copying 1 file to　　C:Documents and SettingsDaniel.grails.6projectsWebFlowDemoclasses　　Generating views for domain class User　　Generating controller for domain class User　　Finished generation for domain class User　　D:_DEVgrails_appsWebFlowDemo>

　　6，将grails-appcontrollersUserController.groovy修改为如下内容

class　UserController {　　def index　=　{ redirect(action:list,params:params) }　　//　the delete, save and update actions only accept POST requests　　def allowedMethods　=　　[delete: ' POST ' , save: ' POST ' , update: ' POST ' ]　　def list　=　{　　if ( ! params.max)params.max　=　 10　　[ userList: User.list( params ) ]　　}　　def show　=　{　　[ user : User.get( params.id ) ]　　}　　def delete　=　{　　def user　=　User.get( params.id )　　if (user) {　　user.delete()　　flash.message　=　 " User ${params.id} deleted. "　　redirect(action:list)　　}　　else　{　　flash.message　=　　" User not found with id ${params.id} "　　redirect(action:list)　　}　　}　　def edit　=　{　　def user　=　User.get( params.id )　　if ( ! user) {　　flash.message　=　　" User not found with id ${params.id} "　　redirect(action:list)　　}　　else　{　　return　[ user : user ]　　}　　}　　def update　=　{　　def user　=　User.get( params.id )　　if (user) {　　user.properties　=　params　　if (user.save()) {　　flash.message　=　　" User ${params.id} updated. "　　redirect(action:show,id:user.id)　　}　　else　{　　render(view: ' edit ' ,model:[user:user])　　}　　}　　else　{　　flash.message　=　　" User not found with id ${params.id} "　　redirect(action:edit,id:params.id)　　}　　}　　def create　=　{　　def user　=　 new　User()　　user.properties　=　params　　return　[ ' user ' :user]　　}　　def save　=　{　　def user　=　 new　User()　　user.properties　=　params　　if (user.save()) {　　flash.message　=　　" User ${user.id} created. "　　redirect(action:show,id:user.id)　　}　　else　{　　render(view: ' create ' ,model:[user:user])　　}　　}　　def loginSystemFlow　=　{　　login {　　on( " login " ) {　　if　( " daniel "　　!=　params.username　||　 " 123 "　　!=　params.password) {　　flash.message　=　　" username or password is invalid "　　def user = new User()　　user.properties = params　　flash.user = user　　return error ()　　} else {　　// 仅仅用来演示如何使用flow scope　　flow.message =　　"Welcome, ${params.username}"　　}　　}.to "ok"　　on("register").to "showRegisterView"　　}　　ok()　　showRegisterView()　　}　　}

　　on("login"){...}.to "ok"表示点击login按钮后所要去的页面为ok，如果验证失败("daniel" != params.username || "123" != params.password)，则利用内置的error()，使用户返回login页面;而on("register").to "showRegisterView"是类似的，不再累述。

　　7，在grails-appviewsuser目录下新建一个名为“loginSystem”的子目录，该名称为UserController.groovy中的loginSystemFlow的“loginSystem”相对应。

　　8，在grails-appviewsuserloginSystem目录下新建login.gsp，ok.gsp，showRegisterView.gsp三个GSP文件(这三个文件的文件名与

　　def loginSystemFlow = {　　login {　　...　　}　　ok()　　showRegisterView()　　}

　　中粗体突显的state名相对应，其中login为start state，而ok和showRegisterView为end state) ，并将其内容修改为：

　　login.gsp

　　< html >　　< head >　　< meta　http-equiv ="Content-Type"　　content ="text/html; charset=UTF-8"　 />　　< meta　name ="layout"　content ="main"　 />　　< title > Login Page　　< body >　　< div　class ="nav" >　　< span　class ="menuButton" >< a　class ="home"　　href ="${createLinkTo(dir:'')}" > Home　　< div　class ="body" >　　< h1 >　　Login Page　　< g:if　test ="${message }" >　　< div　class ="message" >　　${message }　　< g:form　action ="loginSystem"　method ="post" >　　< div　class ="dialog" >　　< table >　　< tbody >　　< tr　class ='prop' >　　< td　valign ='top'　class ='name' >　　< label　for ='username' >　　Username:　　< td　valign ='top'　class ='value　　${hasErrors(bean:user,field:'username','errors')}' >　　< input　type ="text"　　id ='username'　name ='username'　　value ="${user?　　.username?.encodeAsHTML()}"　 />　　< tr　class ='prop' >　　< td　valign ='top'　class ='name' >　　< label　for ='password' >　　Password:　　< td　valign ='top'　class =　　'value　${hasErrors(bean:user,field:'password','errors')}' >　　< input　type ="text"　　id ='password'　name ='password'　　value ="${user?　　.password?.encodeAsHTML()}"　 />　　< div　class ="buttons" >　　< span　class ="button" >< g:submitButton　class ="save"　　name ="login"　value ="Login" >　　< g:link　action ="loginSystem"　event ="register" >　　Register　　ok.gsp　　${message } < br　/>　　< g:link　action ="loginSystem" > back to login page　　showRegisterView.gsp　　This is a register page　< br　/>　　< g:link　action ="loginSystem" > back to login page

　　9，“grails run-app”，启动Grails应用，输出如下

　　D:_DEVgrails_appsWebFlowDemo>grails run-app　　Welcome to Grails 0.6 - http://grails.org/　　Licensed under Apache Standard License 2.0　　Grails home is set to: D:DMY_DEVgrails0.6　　Base Directory: D:_DEVgrails_appsWebFlowDemo　　Environment set to development　　Note: No plugin scripts found　　Running script D:DMY_DEVgrails0.6scriptsRunApp.groovy　　[mkdir] Created dir:　　D:_DEVgrails_appsWebFlowDemoweb-appWEB-INFlib　　Compiling 1 source files to　　C:Documents and SettingsDaniel.grails.6projectsWebFlowDemoclasses　　Running Grails application..　　2007-09-08 00:12:24.443::INFO:　Logging to STDERR via org.mortbay.log.StdErrLog　　2007-09-08 00:12:24.521::INFO:　jetty-6.1.4　　2007-09-08 00:12:26.425:/WebFlowDemo:　　INFO:　Set web app root system property: '@grails.project.key@'　　= [D:_DEVgrails_appsWebFlowDemoweb-app]　　2007-09-08 00:12:26.425:/WebFlowDemo:　　INFO:　Initializing Log4J from　　[D:_DEVgrails_appsWebFlowDemoweb-appWEB-INFclasseslog4j.properties]　　2007-09-08 00:12:26.472:/WebFlowDemo:　　INFO:　Loading Spring root WebApplicationContext　　[9282] hibernate.ConfigurableLocalSessionFactoryBean　　Building new Hibernate SessionFactory　　[9922] mvc.GrailsUrlHandlerMapping Neither 'urlMap'　　nor 'mappings' set on SimpleUrlHandlerMapping　　[12750] commons.GrailsConfigUtils [GrailsContextLoader] Grails application loaded.　　[12797] mvc.GrailsWebRequestFilter Initializing filter 'grailsWebRequest'　　[12797] mvc.GrailsWebRequestFilter Filter 'grailsWebRequest' configured successfully　　[12797] filter.UrlMappingsFilter Initializing filter 'urlMapping'　　[12797] filter.UrlMappingsFilter Initializing filter 'urlMapping'　　[12797] filter.UrlMappingsFilter Filter 'urlMapping' configured successfully　　[12797] filter.UrlMappingsFilter Filter 'urlMapping' configured successfully　　[12797] filter.GrailsReloadServletFilter Initializing filter 'reloadFilter'　　[12797] filter.GrailsReloadServletFilter Filter 'reloadFilter' configured successfully　　[12891] servlet.GrailsDispatcherServlet Initializing servlet 'grails'　　[12954] servlet.GrailsDispatcherServlet　　FrameworkServlet 'grails': initialization started　　2007-09-08 00:12:36.562:/WebFlowDemo:　　INFO:　Loading WebApplicationContext for Spring FrameworkServlet 'grails'　　[13485] servlet.GrailsDispatcherServlet　　Using context class [org.codehaus.groovy.grails.commons.spring.GrailsWebApplicationContext]　　for servlet 'grails'　　[13485] servlet.GrailsDispatcherServlet　　Using MultipartResolver [org.springframework.web.multipart　　.commons.CommonsMultipartResolver@dd7404]　　[13485] servlet.GrailsDispatcherServlet　　Using LocaleResolver [org.springframework.web.servlet.i18n.SessionLocaleResolver@ebbf5c]　　[13500] servlet.GrailsDispatcherServlet　　Unable to locate ThemeResolver with name 'themeResolver':　　using default [org.springframework.web.servlet.　　theme.FixedThemeResolver@192c766]　　[13516] servlet.GrailsDispatcherServlet　　No HandlerAdapters found in servlet 'grails': using default　　[13532] servlet.GrailsDispatcherServlet　　Unable to locate RequestToViewNameTranslator with name 'viewNameTranslator':　　using default [org.springfra　　mework.web.servlet.view.DefaultRequestToViewNameTranslator@a40575]　　[13532] servlet.GrailsDispatcherServlet　　Using MultipartResolver　　[org.springframework.web.multipart.commons.CommonsMultipartResolver@dd7404]　　[13532] servlet.GrailsDispatcherServlet　　FrameworkServlet 'grails': initialization completed in 578 ms　　[13532] servlet.GrailsDispatcherServlet Servlet 'grails' configured successfully　　2007-09-08 00:12:37.374::INFO:　Started SelectChannelConnector@0.0.0.0:8080　　Server running. Browse to http://localhost:8080/WebFlowDemo

　　10，访问http://localhost:8080/WebFlowDemo/user/loginSystem

　　11，输入任意登录信息，并按一下Login按钮，我直接按Login按钮 :)

　　12，输入daniel和123，并按一下Login按钮

　　Welcome, daniel

　　back to login page

　　13，点击"back to login page"链接，在点击login页面上的Register链接

　　This is a register page

　　back to login page

　　一个最简单的Spring Web Flow应用完成。