First they ignore you
then they ridicule you
then they fight you
then you win
    -- Mahatma Gandhi
Chinese => English     英文 => 中文             
随笔-219  评论-1047  文章-0  trackbacks-0
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:\_DEV\grails_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:\D\MY_DEV\grails0.6

Base Directory: D:\_DEV\grails_apps
Environment set to development
Note: No plugin scripts found
Running script D:\D\MY_DEV\grails0.6\scripts\CreateApp.groovy
Overriding previous definition of reference to groovyJarSet
    [mkdir] Created dir: D:\_DEV\grails_apps\WebFlowDemo\src
    [mkdir] Created dir: D:\_DEV\grails_apps\WebFlowDemo\src\java
    [mkdir] Created dir: D:\_DEV\grails_apps\WebFlowDemo\src\groovy
    [mkdir] Created dir: D:\_DEV\grails_apps\WebFlowDemo\grails-app
    [mkdir] Created dir: D:\_DEV\grails_apps\WebFlowDemo\grails-app\controllers
    [mkdir] Created dir: D:\_DEV\grails_apps\WebFlowDemo\grails-app\services
    [mkdir] Created dir: D:\_DEV\grails_apps\WebFlowDemo\grails-app\domain
    [mkdir] Created dir: D:\_DEV\grails_apps\WebFlowDemo\grails-app\taglib
    [mkdir] Created dir: D:\_DEV\grails_apps\WebFlowDemo\grails-app\utils
    [mkdir] Created dir: D:\_DEV\grails_apps\WebFlowDemo\grails-app\views
    [mkdir] Created dir: D:\_DEV\grails_apps\WebFlowDemo\grails-app\views\layouts
    [mkdir] Created dir: D:\_DEV\grails_apps\WebFlowDemo\grails-app\i18n
    [mkdir] Created dir: D:\_DEV\grails_apps\WebFlowDemo\grails-app\conf
    [mkdir] Created dir: D:\_DEV\grails_apps\WebFlowDemo\test
    [mkdir] Created dir: D:\_DEV\grails_apps\WebFlowDemo\test\unit
    [mkdir] Created dir: D:\_DEV\grails_apps\WebFlowDemo\test\integration
    [mkdir] Created dir: D:\_DEV\grails_apps\WebFlowDemo\scripts
    [mkdir] Created dir: D:\_DEV\grails_apps\WebFlowDemo\web-app
    [mkdir] Created dir: D:\_DEV\grails_apps\WebFlowDemo\web-app\js
    [mkdir] Created dir: D:\_DEV\grails_apps\WebFlowDemo\web-app\css
    [mkdir] Created dir: D:\_DEV\grails_apps\WebFlowDemo\web-app\images
    [mkdir] Created dir: D:\_DEV\grails_apps\WebFlowDemo\web-app\WEB-INF\classes
    [mkdir] Created dir: D:\_DEV\grails_apps\WebFlowDemo\web-app\META-INF
    [mkdir] Created dir: D:\_DEV\grails_apps\WebFlowDemo\lib
    [mkdir] Created dir: D:\_DEV\grails_apps\WebFlowDemo\grails-app\conf\spring
    [mkdir] Created dir: D:\_DEV\grails_apps\WebFlowDemo\grails-app\conf\hibernate
[propertyfile] Creating new property file: D:\_DEV\grails_apps\WebFlowDemo\application.properties
     [copy] Copying 2 files to D:\_DEV\grails_apps\WebFlowDemo
     [copy] Copying 2 files to D:\_DEV\grails_apps\WebFlowDemo\web-app\WEB-INF
     [copy] Copying 5 files to D:\_DEV\grails_apps\WebFlowDemo\web-app\WEB-INF\tld
     [copy] Copying 131 files to D:\_DEV\grails_apps\WebFlowDemo\web-app
     [copy] Copying 1 file to D:\_DEV\grails_apps\WebFlowDemo\grails-app\conf
     [copy] Copying 13 files to D:\_DEV\grails_apps\WebFlowDemo\grails-app
     [copy] Copying 1 file to D:\_DEV\grails_apps\WebFlowDemo\grails-app\conf\spring
     [copy] Copying 1 file to D:\_DEV\grails_apps\WebFlowDemo
     [copy] Copying 1 file to D:\_DEV\grails_apps\WebFlowDemo
     [copy] Copying 1 file to D:\_DEV\grails_apps\WebFlowDemo
[propertyfile] Updating property file: D:\_DEV\grails_apps\WebFlowDemo\application.properties
Created Grails Application at D:\_DEV\grails_apps/WebFlowDemo
D:\_DEV\grails_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:\_DEV\grails_apps\WebFlowDemo>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:\D\MY_DEV\grails0.6

Base Directory: D:\_DEV\grails_apps\WebFlowDemo
Environment set to development
Note: No plugin scripts found
Running script D:\D\MY_DEV\grails0.6\scripts\CreateDomainClass.groovy
     [copy] Copying 1 file to D:\_DEV\grails_apps\WebFlowDemo\grails-app\domain
Created  for User
     [copy] Copying 1 file to D:\_DEV\grails_apps\WebFlowDemo\test\integration
Created Tests for User
D:\_DEV\grails_apps\WebFlowDemo>

4,将grails-app\domain\User.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:\_DEV\grails_apps\WebFlowDemo>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:\D\MY_DEV\grails0.6

Base Directory: D:\_DEV\grails_apps\WebFlowDemo
Environment set to development
Note: No plugin scripts found
Running script D:\D\MY_DEV\grails0.6\scripts\GenerateAll.groovy
    [mkdir] Created dir: C:\Documents and Settings\Daniel\.grails\0.6\projects\WebFlowDemo\classes
Compiling 5 source files to C:\Documents and Settings\Daniel\.grails\0.6\projects\WebFlowDemo\classes
    [mkdir] Created dir: D:\_DEV\grails_apps\WebFlowDemo\web-app\WEB-INF\grails-app\i18n
     [copy] Copying 8 files to D:\_DEV\grails_apps\WebFlowDemo\web-app\WEB-INF\grails-app\i18n
     [copy] Copying 1 file to D:\_DEV\grails_apps\WebFlowDemo\web-app\WEB-INF\spring
     [copy] Copying 1 file to C:\Documents and Settings\Daniel\.grails\0.6\projects\WebFlowDemo\classes
     [copy] Copying 1 file to C:\Documents and Settings\Daniel\.grails\0.6\projects\WebFlowDemo\classes
Generating views for domain class User 
Generating controller for domain class User 
Finished generation for domain class User
D:\_DEV\grails_apps\WebFlowDemo>

6,将grails-app\controllers\UserController.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-app\views\user\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-app\views\user\loginSystem\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 </ title >
    
</ head >
    
< body >
        
< div  class ="nav" >
            
< span  class ="menuButton" >< class ="home"
                href
="${createLinkTo(dir:'')}" > Home </ a >
            
</ span >
        
</ div >
        
< div  class ="body" >
            
< h1 >
                Login Page
            
</ h1 >
            
< g:if  test ="${message }" >
                
< div  class ="message" >
                    ${message }
                
</ div >
            
</ g:if >
            
< g:form  action ="loginSystem"  method ="post" >
                
< div  class ="dialog" >
                    
< table >
                        
< tbody >
                            
< tr  class ='prop' >
                                
< td  valign ='top'  class ='name' >
                                    
< label  for ='username' >
                                        Username:
                                    
</ label >
                                
</ td >
                                
< td  valign ='top'  class ='value  ${hasErrors(bean:user,field:'username','errors')}' >
                                    
< input  type ="text"  id ='username'  name ='username'
                                        
value ="${user?.username?.encodeAsHTML()}"   />
                                
</ td >
                            
</ tr >
                            
< tr  class ='prop' >
                                
< td  valign ='top'  class ='name' >
                                    
< label  for ='password' >
                                        Password:
                                    
</ label >
                                
</ td >
                                
< td  valign ='top'  class ='value  ${hasErrors(bean:user,field:'password','errors')}' >
                                    
< input  type ="text"  id ='password'  name ='password'
                                        
value ="${user?.password?.encodeAsHTML()}"   />
                                
</ td >
                            
</ tr >
                        
</ tbody >
                    
</ table >
                
</ div >
                
< div  class ="buttons" >
                    
< span  class ="button" >< g:submitButton  class ="save"
                            name
="login"  value ="Login" ></ g:submitButton >
                    
</ span >
                
</ div >
                
< g:link  action ="loginSystem"  event ="register" > Register </ g:link >
            
</ g:form >
        
</ div >
    
</ body >
</ html >

ok.gsp
${message } < br  />

< g:link  action ="loginSystem" > back to login page </ g:link >

showRegisterView.gsp
This is a register page  < br  />
< g:link  action ="loginSystem" > back to login page </ g:link >


9,“grails run-app”,启动Grails应用,输出如下
D:\_DEV\grails_apps\WebFlowDemo>grails run-app

Welcome to Grails 0.6 - http://grails.org/
Licensed under Apache Standard License 2.0
Grails home is set to: D:\D\MY_DEV\grails0.6

Base Directory: D:\_DEV\grails_apps\WebFlowDemo
Environment set to development
Note: No plugin scripts found
Running script D:\D\MY_DEV\grails0.6\scripts\RunApp.groovy
    [mkdir] Created dir: D:\_DEV\grails_apps\WebFlowDemo\web-app\WEB-INF\lib
Compiling 1 source files to C:\Documents and Settings\Daniel\.grails\0.6\projects\WebFlowDemo\classes
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:\_DEV\grails_apps\WebFlowDemo\web-app\]

2007-09-08 00:12:26.425:/WebFlowDemo:INFO:  Initializing Log4J from [D:\_DEV\grails_apps\WebFlowDemo\web-app\WEB-INF\classes\log4j.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。

最后告诉大家一个好消息,《Grails权威指南》最晚将在下个月出版,喜欢Grails的朋友到时可以买一本系统地学习一下Grails这个强大的框架,为自己今后的开发注入新的活力。关于此书的一些说明可以看一下
《Grails权威指南》译者序(草稿)

附:朝花夕拾——Groovy & Grails
posted on 2007-09-08 00:39 山风小子 阅读(5524) 评论(3)  编辑  收藏 所属分类: Groovy & Grails