MESSL（maven + extjs + spring portlet mvc + spring web flow + liferay ）整合架构 5

流控制文件很简单，就是根元素是<view>,然后用<view-state>来代表一个一个的页面，用<transition>来代表从一个状态到另外一个状态的跳转，如果有动作要执行就会加在其中。

对于一个普通的java工程师，一般不需要超过1小时就可以熟知这个文件的编写方法,可查阅相关文档。

对于我们的flow,大体上如下所示：

因为图片实在太长，所以我没办法吧整个图片都截下来，这里只截取部分，对于flow定义的xml文件，我完整列在这里，可以供读者参考：

  
  


   
   
<?xml version="1.0" encoding="UTF-8"?> 

   
   
<flow xmlns="http://www.springframework.org/schema/webflow" 

   
   
      xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance" 

   
   
      xsi:schemaLocation="http://www.springframework.org/schema/webflow http://www.springframework.org/schema/webflow/spring-webflow-2.0.xsd"> 

   
   
     

   
   
     

   
   
    <!-- initialize all the variables in the flowScope --> 

   
   
    <on-start> 

   
   
        <evaluate expression="envProvisionInitService.initialize(flowRequestContext)" /> 

   
   
         

   
   
        <!-- initialize the flowScope variable:gridList to render the grid list --> 

   
   
        <!-- <evaluate expression="aerEnvGridService.listAppEnvRequests()" 

   
   
                   result="flowScope.gridListInfoJSONData" /> 

   
   
         -->            

   
   
        <!--  initialize the flowScope variable: availableServices to be used in hostvip info --> 

   
   
        <evaluate expression="defineHostVipService.listAvailableServices()" 

   
   
                   result="flowScope.availableServicesInfoJSONData" /> 

   
   
                    

   
   
        <set name="flowScope.isViewAction" value="false" type="boolean" /> 

   
   
                    

   
   
    </on-start> 

   
   
     

   
   
    <view-state id="aerEnvList" > 

   
   
     

   
   
        <on-render> 

   
   
          <evaluate expression="aerEnvGridService.listAppEnvRequests()" result="flowScope.gridListInfoJSONData" /> 

   
   
        </on-render> 

   
   
         

   
   
        <transition on="add" to="defineApp" /> 

   
   
        <transition on="confirm" to="aerRequestConfirm" > 

   
   
            <!-- fetch the data from web service and ready for populating data --> 

   
   
            <evaluate expression="aerEnvGridService.listEnvProvisionInfoByRequestId(requestParameters.requestId,flowRequestContext)"/> 

   
   
            <set name="flowScope.isViewAction" value="true" type="boolean" /> 

   
   
            <set name="flowScope.requestId" value="requestParameters.requestId" type="string"/> 

   
   
        </transition> 

   
   
        <transition on="approve" to="aerEnvList"> 

   
   
            <evaluate expression="adminService.approve(requestParameters.requestId)" /> 

   
   
        </transition> 

   
   
        <transition on="close" to="aerEnvList"> 

   
   
            <evaluate expression="adminService.close(requestParameters.requestId)" /> 

   
   
        </transition> 

   
   
        <transition on="reject" to="aerEnvList"> 

   
   
            <evaluate expression="adminService.reject(requestParameters.requestId)" /> 

   
   
        </transition> 

   
   
        <transition on="cmdb" to="aerEnvList"> 

   
   
            <evaluate expression="adminService.cmdb(requestParameters.requestId)" /> 

   
   
        </transition> 

   
   
    </view-state> 

   
   
 

   
   
    <view-state id="defineApp" >          

   
   
     

   
   
        <transition on="next" to="defineProject"> 

   
   
          <evaluate expression="defineAppService.createAppInfo(requestParameters.appInfoJSONData)" 

   
   
                   result="flowScope.appInfo"  /> 

   
   
          <set name="flowScope.appInfoJSONData" value="requestParameters.appInfoJSONData" type="string"/> 

   
   
          <set name="flowScope.hasAppInfoData" value="true" type="boolean"/> 

   
   
        </transition> 

   
   
        <transition on="cancel" to="aerEnvList" > 

   
   
            <evaluate expression="defineAppService.removeAppInfo(flowRequestContext)" /> 

   
   
            <evaluate expression="defineProjectService.removeProjectInfo(flowRequestContext)" /> 

   
   
            <evaluate expression="defineHostVipService.removeHostVipInfo(flowRequestContext)" /> 

   
   
            <evaluate expression="defineDBSrvService.removeDBServiceInfo(flowRequestContext)"/> 

   
   
        </transition> 

   
   
    </view-state> 

   
   
     

   
   
    <view-state id="defineProject"> 

   
   
        <transition on="previous" to="defineApp"/> 

   
   
         

   
   
        <transition on="next" to="defineHostVip">      

   
   
            <evaluate expression="defineProjectService.createProjectInfo(requestParameters.projectInfoJSONData)" 

   
   
                      result="flowScope.projectInfo"  /> 

   
   
            <set name="flowScope.projectInfoJSONData" value="requestParameters.projectInfoJSONData" type="string"/> 

   
   
            <set name="flowScope.hasProjectInfoData" value="true" type="boolean"/> 

   
   
        </transition> 

   
   
        <transition on="cancel" to="aerEnvList"> 

   
   
            <evaluate expression="defineAppService.removeAppInfo(flowRequestContext)" /> 

   
   
            <evaluate expression="defineProjectService.removeProjectInfo(flowRequestContext)" /> 

   
   
            <evaluate expression="defineHostVipService.removeHostVipInfo(flowRequestContext)" /> 

   
   
            <evaluate expression="defineDBSrvService.removeDBServiceInfo(flowRequestContext)"/> 

   
   
        </transition> 

   
   
    </view-state> 

   
   
     

   
   
    <view-state id="defineHostVip"> 

   
   
        <transition on="previous" to="defineProject"/> 

   
   
 

   
   
        <transition on="next" to="defineDBService"> 

   
   
            <evaluate expression="defineHostVipService.createHostVipInfo(requestParameters.hostVipInfoJSONData, flowRequestContext)" 

   
   
                      result="flowScope.hostVipInfo"  /> 

   
   
            <set name="flowScope.hostVipInfoJSONData" value="requestParameters.hostVipInfoJSONData" type="string"/> 

   
   
            <!-- additional set one field to pass the service list to next page(defineDBService.jsp) --> 

   
   
            <set name="flowScope.hasHostVipInfoData" value="true" type="boolean"/> 

   
   
            <set name="flowScope.services" value="requestParameters.services" type="string" /> 

   
   
        </transition> 

   
   
        <transition on="cancel" to="aerEnvList"> 

   
   
            <evaluate expression="defineAppService.removeAppInfo(flowRequestContext)" /> 

   
   
            <evaluate expression="defineProjectService.removeProjectInfo(flowRequestContext)" /> 

   
   
            <evaluate expression="defineHostVipService.removeHostVipInfo(flowRequestContext)" /> 

   
   
            <evaluate expression="defineDBSrvService.removeDBServiceInfo(flowRequestContext)"/> 

   
   
        </transition> 

   
   
    </view-state> 

   
   
     

   
   
    <view-state id="defineDBService"> 

   
   
        <transition on="previous" to="defineHostVip"/> 

   
   
     

   
   
        <transition on="next" to="aerRequestConfirm"> 

   
   
            <evaluate expression="defineDBSrvService.createDBServiceInfo(requestParameters.dbServiceInfoJSONData, flowRequestContext)" 

   
   
                      result="flowScope.dbServiceInfo"  /> 

   
   
            <set name="flowScope.dbServiceInfoJSONData" value="requestParameters.dbServiceInfoJSONData" type="string"/> 

   
   
            <set name="flowScope.hasDbServiceInfoData" value="true" type="boolean"/> 

   
   
            <set name="flowScope.isSubmitted" value="false" type="boolean"/> 

   
   
            <set name="flowScope.isViewAction" value="false" type="boolean" /> 

   
   
        </transition> 

   
   
        <transition on="cancel" to="aerEnvList"> 

   
   
            <evaluate expression="defineAppService.removeAppInfo(flowRequestContext)" /> 

   
   
            <evaluate expression="defineProjectService.removeProjectInfo(flowRequestContext)" /> 

   
   
            <evaluate expression="defineHostVipService.removeHostVipInfo(flowRequestContext)" /> 

   
   
            <evaluate expression="defineDBSrvService.removeDBServiceInfo(flowRequestContext)"/> 

   
   
        </transition> 

   
   
    </view-state> 

   
   
     

   
   
    <view-state id="aerRequestConfirm"> 

   
   
        <transition on="previous" to="defineDBService"/> 

   
   
        <transition on="submit" to="aerRequestSummary">       

   
   
            <evaluate expression="envProvisionRequestService.submitEnvProvisionRequest(flowRequestContext)" 

   
   
                      result="flowScope.submitResult"  /> 

   
   
        </transition> 

   
   
         

   
   
        <!--  

   
   
        <transition on="submit" to="aerRequestSummary"/> 

   
   
        --> 

   
   
        <transition on="cancel" to="aerEnvList"> 

   
   
            <evaluate expression="defineAppService.removeAppInfo(flowRequestContext)" /> 

   
   
            <evaluate expression="defineProjectService.removeProjectInfo(flowRequestContext)" /> 

   
   
            <evaluate expression="defineHostVipService.removeHostVipInfo(flowRequestContext)" /> 

   
   
            <evaluate expression="defineDBSrvService.removeDBServiceInfo(flowRequestContext)"/> 

   
   
        </transition> 

   
   
         

   
   
        <transition on="adminSubmit" to="aerRequestSummary">          

   
   
            <evaluate expression="envProvisionRequestService.updateEnvProvisionRequest(flowRequestContext)" 

   
   
                      result="flowScope.submitResult"  /> 

   
   
            <set name="flowScope.isViewAction" value="false" type="boolean" /> 

   
   
 

   
   
        </transition> 

   
   
         

   
   
        <!--  

   
   
        <transition on="submit" to="aerRequestSummary"/> 

   
   
        --> 

   
   
        <transition on="adminCancel" to="aerEnvList"> 

   
   
            <evaluate expression="defineAppService.removeAppInfo(flowRequestContext)" /> 

   
   
            <evaluate expression="defineProjectService.removeProjectInfo(flowRequestContext)" /> 

   
   
            <evaluate expression="defineHostVipService.removeHostVipInfo(flowRequestContext)" /> 

   
   
            <evaluate expression="defineDBSrvService.removeDBServiceInfo(flowRequestContext)"/> 

   
   
            <set name="flowScope.isViewAction" value="false" type="boolean" /> 

   
   
        </transition> 

   
   
         

   
   
         

   
   
        <transition on="noAdminOK" to="aerEnvList"> 

   
   
            <evaluate expression="defineAppService.removeAppInfo(flowRequestContext)" /> 

   
   
            <evaluate expression="defineProjectService.removeProjectInfo(flowRequestContext)" /> 

   
   
            <evaluate expression="defineHostVipService.removeHostVipInfo(flowRequestContext)" /> 

   
   
            <evaluate expression="defineDBSrvService.removeDBServiceInfo(flowRequestContext)"/> 

   
   
            <set name="flowScope.isViewAction" value="false" type="boolean" /> 

   
   
        </transition> 

   
   
         

   
   
         

   
   
         

   
   
        <!--add 4 event to distingush different partin the request confirmation page--> 

   
   
        <transition on="editApplicationInfo" to="defineApp"/> 

   
   
        <transition on="editProjectInfo"  to="defineProject"/> 

   
   
        <transition on="editHostVipInfo"  to="defineHostVip"/> 

   
   
        <transition on="editDBServiceInfo"  to="defineDBService"/> 

   
   
    </view-state> 

   
   
     

   
   
    <view-state id="aerRequestSummary"> 

   
   
        <transition on="ok" to="aerEnvList"> 

   
   
            <evaluate expression="defineAppService.removeAppInfo(flowRequestContext)" /> 

   
   
            <evaluate expression="defineProjectService.removeProjectInfo(flowRequestContext)" /> 

   
   
            <evaluate expression="defineHostVipService.removeHostVipInfo(flowRequestContext)" /> 

   
   
            <evaluate expression="defineDBSrvService.removeDBServiceInfo(flowRequestContext)"/> 

   
   
        </transition> 

   
   
    </view-state> 

   
   
     

   
   
    <end-state id="finish"/> 

   
   
             

   
   
</flow> 
  
  

这里，因为我们在这系列的第二篇文章中已经提及到，我们开启了包扫描机制，所以这些Spring的Bean在应用上下文创建的时候就已经实例化了，所以在这个流定义文件中可以轻松的使用这些bean.

 其实在做架构的时候，我曾和我们团队其他开发者讨论到为什么我们用spring web flow,其实这种页面跳转我们也可以不用web flow做，最后采用web flow的架构是基于以下几个原因：

众所周知，一般web应用的scope有 request，session,application,因为在很多配置页面上都有数据，并且这些数据都要共享，还比较大（那些传递的vo动辄100+字段）而且业务流程也比较复杂，而且这些数据还是有状态的，所以我们无法放在request scope上，而如果放在session scope上，又会加重系统的内存负担，所以我们需要一种介于request,session范围之间的scope,而spring web flow刚好提供了flow scope来精确的满足我们的需求，所以我们使用spring web flow.