IllegalArgumentException：無法將類java.util.HashSet的類型[]轉換爲類xxx

Question

我發現自己處於JSF錯誤中，但不知道爲什麼會出現這種錯誤。我會告訴你的看法部分：

<rich:extendedDataTable id="objects" value="#{newObjectsBean.objectsList}" 
      selection="#{newObjectsBean.objectToDelete}" 
      rendered="#{newObjectsBean.anyResult}" 
      selectionMode="single" var="item" rows="10" > 
<a4j:ajax execute="@form" event="selectionchange" 
    listener="#{newObjectsBean.selectionListener}" render="deletionButton"/> 
<rich:column width="125px" sortBy="#{item.sId}" 
    sortOrder="#{fragSortingBean.sortsOrders['sId']}"> 
    <f:facet name="header"> 
    <h:panelGrid columns="2" cellpadding="0" cellspacing="2" 
      style="text-align: left; height: 30px"> 
     <a4j:commandLink execute="@this" value="id" render="objects" 
        action="#{fragSortingBean.sort}"> 
      <f:param name="sortProperty" value="sId"/> 
     </a4j:commandLink> 
     <h:graphicImage value="../../resources/images/arrow_sort_down.png" 
        rendered="#{fragSortingBean.sortsOrders['sId']=='descending'}"/> 
     <h:graphicImage value="../../resources/images/arrow_sort_up.png" 
        rendered="#{fragSortingBean.sortsOrders['sId']=='ascending'}"/> 
    </h:panelGrid> 
</f:facet> 
<h:outputText id="ssaId" value="#{item.sId}"/> 
</rich:column> 

隨後的項目是對象（MyObjectBean）只有三個屬性（及其相應的getter/setter）

問題跟蹤列表如下：

java.lang.IllegalArgumentException: Cannot convert [] of type class java.util.HashSet to class xxx.yyy.zzz.entities.MyObjectBean 
     at com.sun.el.lang.ELSupport.coerceToType(ELSupport.java:397) 
     at com.sun.el.parser.AstValue.setValue(AstValue.java:194) 
     at com.sun.el.ValueExpressionImpl.setValue(ValueExpressionImpl.java:286) 
     at org.jboss.weld.el.WeldValueExpression.setValue(WeldValueExpression.java:88) 
     at com.sun.faces.facelets.el.TagValueExpression.setValue(TagValueExpression.java:124) 
     at org.richfaces.renderkit.SortingFilteringRowsRenderer.updateAttribute(SortingFilteringRowsRenderer.java:142) 
     at org.richfaces.renderkit.SelectionRenderer.doDecode(SelectionRenderer.java:175) 
     at org.richfaces.renderkit.ExtendedDataTableRenderer.doDecode(ExtendedDataTableRenderer.java:805) 
     at org.richfaces.renderkit.RendererBase.decode(RendererBase.java:80) 
     at javax.faces.component.UIComponentBase.decode(UIComponentBase.java:790) 
     at org.richfaces.component.UIDataAdaptor.processDecodes(UIDataAdaptor.java:816) 
     at javax.faces.component.UIComponentBase.processDecodes(UIComponentBase.java:1042) 
     at javax.faces.component.UIComponentBase.processDecodes(UIComponentBase.java:1042) 
     at javax.faces.component.UIComponentBase.processDecodes(UIComponentBase.java:1042) 
     at javax.faces.component.UIForm.processDecodes(UIForm.java:216) 
     at javax.faces.component.UIComponentBase.processDecodes(UIComponentBase.java:1042) 
     at javax.faces.component.UIComponentBase.processDecodes(UIComponentBase.java:1042) 
     at javax.faces.component.UIViewRoot.processDecodes(UIViewRoot.java:941) 
     at com.sun.faces.lifecycle.ApplyRequestValuesPhase.execute(ApplyRequestValuesPhase.java:78) 
     at com.sun.faces.lifecycle.Phase.doPhase(Phase.java:101) 
     at com.sun.faces.lifecycle.LifecycleImpl.execute(LifecycleImpl.java:118) 
     at javax.faces.webapp.FacesServlet.service(FacesServlet.java:312) 

任何線索？ 在此先感謝

Answer 1

@選擇EDT必須評估爲一個集合，它看起來像你的指向一個單一的對象。