c为C：的forEach>将项目属性视为字符串 [英] <c:forEach> treats items property as a string

问题描述

我尝试使用< c：forEach> 来迭代一组元素，它们是复杂类型（另一个实体）：

 < c：forEach items =＃{repcatTree.items}var =item> 
< div style =padding-top：7px; padding-bottom：7px; padding-right：15px;> 
< span class =report_item_category_class> 
 < h：graphicImage url =/ views / tree / images / folder_big.gif/> 
< h：outputText value =＃{item.attributes.FILE_NAME}style =font-size：14px; font-weight：bold; padding-left：5px/> 
< / h：commandLink> 
< h：commandLink rendered =＃{item.type =='report'}styleClass =default_linkaction =action_report_runtitle =＃{item.cells ['report_name']。toolTip} > 
 < h：outputText value =＃{item.cells ['report_name']。display}style =font-size：14px; font-weight：bold; padding-left：5px/> 
< f：param name =nodePathvalue =＃{item.attributes.RDD_PATH}/> 
 < / h：commandLink> 
< / span> 
< / div> 
< / c：forEach> 
  

但是，forEach块逻辑内部将'＃{item}'元素视为常规 java.lang.String 导致

javax.el.PropertyNotFoundException：类'java.lang .String'没有'type'属性。

这是我的 faces-config.xml （JSF 1.2）相关的映射条目：



 < managed-bean> 
< managed-bean-name> repcatTree< / managed-bean-name> 
< managed-bean-class> rpt.engine.runner.tree.impl.RepcatTreeModel< / managed-bean-class> 
< managed-bean-scope> session< / managed-bean-scope> 
< managed-property> 
< property-name>路径< / property-name> 
< property-class> java.lang.String< / property-class> 
<值> /< /值> 
< / managed-property> 
< managed-property> 
< property-name>侦听器< / property-name> 
< property-class> rpt.engine.runner.tree.listeners.ReportsTreeModelListener< / property-class> 
<值>＃{reportsTreeModelListener}< /值> 
< / managed-property> 
< managed-property> 
< property-name> tableModel< / property-name> 
< property-class> rpt.engine.runner.table.TableModel< / property-class> 
<值>＃{repcatTableModel}< /值> 
< / managed-property> 
< / managed-bean> 
  

这是如何引起的，我该如何解决它？





JSF 1.2意味着最小的Servlet 2.5（您的webapp的 web.xml 也必须这样声明！） ，这又意味着最小的JSTL 1.2，这又意味着的taglib URI http://java.sun.com/jsp/jstl/core 。 p>

确保你的一切都正确。您的特殊问题是由于＃{repcatTree.items} 未被解释为EL表达式，而是作为纯字符串，表明EL在JSTL中根本不起作用，这反过来表明你可能使用JSTL 1.0 / 1.1（注意Glassfish已经捆绑了JSTL，所以你不应该随你的webapp一起发布），或者使用JSTL 1.0 taglib URI而不用 / jsp 路径或者 web.xml 未声明符合Servlet 2.5。

另见：

• 我们的JSTL wiki页面 - 包含下载链接和安装说明

I am trying to iterate over a collection of elements, which are complex types (another entities) using <c:forEach>:

<c:forEach items="#{repcatTree.items}" var="item">
    <div style="padding-top:7px; padding-bottom:7px; padding-right:15px;">
        <span class="report_item_category_class">
            <h:commandLink rendered="#{item.type == 'category'}" action="#{item.onNodeClicked}" styleClass="default_link">
                <h:graphicImage url="/views/tree/images/folder_big.gif" />
                <h:outputText value="#{item.attributes.FILE_NAME}" style="font-size:14px; font-weight:bold; padding-left:5px" />
            </h:commandLink>
            <h:commandLink rendered="#{item.type == 'report'}" styleClass="default_link" action="action_report_run" title="#{item.cells['report_name'].toolTip}">
                <h:graphicImage url="/icon?rdd_path=#{item.attributes.RDD_PATH}" />               
                <h:outputText value="#{item.cells['report_name'].display}" style="font-size:14px; font-weight:bold; padding-left:5px" />
                <f:param name="nodePath" value="#{item.attributes.RDD_PATH}" />
                <f:param name="nodePrettyPath" value="#{item.attributes.CAT_PATH}" />
            </h:commandLink>
        </span>
    </div>
</c:forEach>

However, inside of forEach block logic treats '#{item}' element as a regular java.lang.String causing

javax.el.PropertyNotFoundException: The class 'java.lang.String' does not have the property 'type'.

Here's my faces-config.xml (JSF 1.2) related mapping entry:

<managed-bean>
    <managed-bean-name>repcatTree</managed-bean-name>   
    <managed-bean-class>rpt.engine.runner.tree.impl.RepcatTreeModel</managed-bean-class>
    <managed-bean-scope>session</managed-bean-scope>
    <managed-property>
        <property-name>path</property-name>
        <property-class>java.lang.String</property-class>
        <value>/</value>
    </managed-property>
    <managed-property>
        <property-name>listener</property-name>
        <property-class>rpt.engine.runner.tree.listeners.ReportsTreeModelListener</property-class>
        <value>#{reportsTreeModelListener}</value>
    </managed-property>       
    <managed-property>
        <property-name>tableModel</property-name>
        <property-class>rpt.engine.runner.table.TableModel</property-class>
        <value>#{repcatTableModel}</value>
    </managed-property>
</managed-bean> 

How is this caused and how can I solve it?

解决方案

That can happen if you used the wrong JSTL version for the environment or used the wrong JSTL taglib URI declaration.

JSF 1.2 implies a minimum of Servlet 2.5 (your webapp's web.xml must also be declared as such!), which in turn implies a minimum of JSTL 1.2, which in turn implies a taglib URI of http://java.sun.com/jsp/jstl/core.

Make sure you got everything right. Your particular problem is caused because #{repcatTree.items} is not interpreted as an EL expression, but instead as plain string, indicating that EL in JSTL doesn't work at all, which in turn indicates that you're possibly using JSTL 1.0/1.1 (note that Glassfish already bundles JSTL, so you should not ship any along with your webapp), or used the JSTL 1.0 taglib URI without the /jsp path, or the web.xml is not declared conform Servlet 2.5.

See also:

• Our JSTL wiki page - contains download links and installation instructions

这篇关于c为C：的forEach>将项目属性视为字符串的文章就介绍到这了，希望我们推荐的答案对大家有所帮助，也希望大家多多支持IT屋！