JSF - panelgroup绑定 - 只添加一次子进程 - java.lang.IllegalStateException：CDATA标记可能无法嵌套

Question

我正在尝试将h：panelGroup绑定到UIComponent（HtmlPanelGroup）代码，如：

p.s我正在使用faces-config.xml

import javax.annotation.PostConstruct;
import javax.faces.bean.ViewScoped;
import javax.faces.component.html.HtmlOutputLabel;
import javax.faces.component.html.HtmlPanelGroup;
import javax.faces.event.ActionEvent;


    @ViewScoped
    public class PanelGroupUpdater1 {

    private HtmlPanelGroup hpg0;

        @PostConstruct
        public void init(){

            hpg0=new HtmlPanelGroup();
            hpg0.setLayout("block");
            hpg0.setStyleClass("myBindedPanelGroup0");

            HtmlOutputLabel l = new HtmlOutputLabel();
            //l.setValue("Synched binded panel group : ");
            hpg0.getChildren().add(l);


        }

      int h;
        public void addLabelBindedSynched(ActionEvent event) {
            //update panelgroup by its binding


                HtmlOutputLabel l = new HtmlOutputLabel();
                l.setValue("added:"+(++h)+";");
                this.hpg0.getChildren().add(l);     
        }

    }

和WebContent / test / bindingtest.xhtml

<h:body>

<f:view>


Binded panel group (hpg0) : <br/>
<h:panelGroup id="myBindedPanelGroup0" binding="#{panelGroupUpdaterBean1.hpg0}" layout="block">
</h:panelGroup>

<h:form>
    <h:commandButton value="Add Label (binded)" actionListener="#{panelGroupUpdaterBean1.addLabelBindedSynched}" update=":myBindedPanelGroup0" />
</h:form>

</f:view>

</h:body>

问题是我可以只向panelgroup添加一次标签，但是所有下一次添加尝试我都会得到此异常java.lang.IllegalStateException: CDATA tags may not nest。

所以我的问题是......导致问题的原因以及如何解决这个问题？

由于