关于雅加达ee：PrimeFaces数据表：使用GlassFish Mojarra由ClassCastException(无stacktrace)引起的奇怪ELException

PrimeFaces dataTable: strange ELException caused by ClassCastException (no stacktrace) using GlassFish + Mojarra

我们有一个碰撞实体列表，您可以在PrimeFaces <p:datatable>中进行单选。在该字段的下面是一个字段集，该字段集显示了相关的历史记录和文件附件。

这是JSF页面(附件数据表比其他数据表更重要)：

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<h:panelGrid>

<p:scrollPanel mode="native">
<p:dataTable value="#{collisionManager.selectedCollisions}"
var="cln"
selection="#{collisionManager.selectedStateChangeCollision}"
selectionMode="single"
rowKey="#{cln.id}"
paginator="true"
paginatorPosition="bottom"
rows="5">

<p:ajax event="rowSelect" process="@this" update="@form" />

<p:column headerText="ID">
<h:outputText value="#{cln.id}" />
</p:column>

...

</p:dataTable>
</p:scrollPanel>

<p:fieldset legend="History and Attachments">

<p:tabView widgetVar="stateChangeTabView"
dynamic="true"
cache="false">

<p:tab title="History">
...
</p:tab>

<p:tab title="Attachments">
<p:dataTable id="attachments-datatable"
value="#{attachmentManager.activeAttachments}"
var="att"
paginator="true"
paginatorPosition="bottom"
rows="3">

<p:column headerText="File Name">
<h:outputText value="#{att.fileName}" />
</p:column>

<p:column headerText="Deleted">
<h:outputText value="#{att.deleted}" />
</p:column>

<p:column headerText="Marked">
<h:outputText value="#{attachmentManager.markedToDelete(att)}" />
</p:column>

<p:column headerText="Actions">
<p:commandButton icon="ui-icon ui-icon-trash"
title="Mark to delete"
action="#{attachmentManager.markToDelete(att)}"
process="@this"
update="@form"
rendered="#{not attachmentManager.markedToDelete(att)}">
</p:commandButton>
<p:commandButton icon="ui-icon ui-icon-cancel"
title="Unmark to delete"
action="#{attachmentManager.unmarkToDelete(att)}"
process="@this"
update="@form"
rendered="#{not attachmentManager.markedToDelete(att)}">
</p:commandButton>
</p:column>
</p:dataTable>
</p:tab>

</p:tabView>

</p:fieldset>

</h:panelGrid>

这里是AttachmentManager bean(@Named和@Viewscoped兼容的类路径上有Seam 3 Faces，在这里无关紧要)：

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@Named
@ViewScoped
public class AttachmentManager implements Serializable
{
// attachments to be deleted
private List<Attachment> markedAttachments;

public void markToDelete( Attachment attachment )
{
if ( !this.markedAttachments.contains( attachment ) )
{
this.markedAttachments.add( attachment );
}
}

public void unmarkToDelete( Attachment attachment )
{
this.markedAttachments.remove( attachment );
}

public boolean markedToDelete( Attachment attachment )
{
return this.markedAttachments.contains( attachment );
}
}

在行(附件表)的页面上评估表达式时，问题开始：

1	<h:outputText value="#{attachmentManager.markedToDelete(att)}" />

上面的代码中实际执行哪个表达式都没有关系，它们基本上都会失败：

1	javax.el.ELException: /view/changeData.xhtml @184,102 value="#{not attachmentManager.markedToDelete(att)}": java.lang.ClassCastException: com.company.project.model.Attachment cannot be cast to com.company.project.model.Collision

请注意，绝对没有堆栈跟踪-至少不是我能够找到一个。我什至查看了服务器响应(AJAX)，发现其中有些异常有时会被吞没-没事。

我发现了另外两个与我的问题有关的帖子(也未解决)：

http://forum.primefaces.org/viewtopic.php?f=3