Question

我有cardQuestion.jspx

<html xmlns:jsp="http://java.sun.com/JSP/Page"
  xmlns:form="http://www.springframework.org/tags/form" contenteditable="inherit">
<jsp:output omit-xml-declaration="yes" />
 <jsp:directive.page contentType="text/html;charset=UTF-8" />  

   <head>
     <title>SS</title>
   </head>
  <body>

<label>${wordingPractice.question}</label>

 </body>
</html>

我有流声明wording-flow.xml

<?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">
<var name="wordingPractice" class="Practice.WordingPractice"/>    

<view-state id="wording">
   <transition on="next" to="setTranslationDirection"/>
   <transition on="cancel" to="endState"/>
</view-state>      

<action-state id="setTranslationDirection">
    <evaluate expression="wordingPractice.translationDirection = requestParameters.translationDirection"/>
   <transition to="setSaver"/>
</action-state>

<action-state id="setSaver">
    <evaluate expression="wordingPractice.saver = saverExtension"/>
   <transition to="nextCard"/>
</action-state>

<action-state id="nextCard">
   <evaluate expression="wordingPractice.nextCard()"/>
   <transition to="cardQuestion"/>
</action-state>

<view-state id="cardQuestion">
   <transition on="cancel" to="endState"/>
</view-state>

<end-state id="endState" />   
</flow>

在方法nextCard中 - 我初始化问题变量。但是当我在jspx中调用它时：$ {wordingPractice.question} 它让我得到Null指针异常。另外，当我调试时，我看到当我调用nextCard时 - 这是ObjectID1，但是当我调用getQuestion时 - 这是ObjectID2。

如何在jspx中访问流变量？

Answer 1

我通过改变方法来解决它：

<view-state id="cardQuestion">
   <on-entry>
       <evaluate result="viewScope.questionValue" expression="wordingPractice.question"/>
   </on-entry>
   <transition on="cancel" to="endState"/>
</view-state>

和jspx

<label>${questionValue}</label>

但如果有人知道如何在viewScope中使用对象 - 欢迎回答！

当我尝试做同样的事情时：

 <evaluate result="viewScope.wordingPractice" expression="wordingPractice"/>

我遇到与空指针相同的问题

Answer 2

您需要使用包含视图表单字段的流动变量变量指定模型属性。

    <view-state id="wording" model="wordingPractice">
       <transition on="next" to="setTranslationDirection"/>
       <transition on="cancel" to="endState"/>
    </view-state>

    <view-state id="cardQuestion" model="wordingPractice">
       <transition on="cancel" to="endState"/>
    </view-state>

在jspx中无法访问flowScope变量

2 个答案: