Primefaces程序菜单

Question

这是我的xhtml

page.sorting = count

这是我的豆子

        <h:form> 
        <p:growl id="messages" showDetail="false"/>
          <p:menubar>
                    <p:submenu label="Report" icon="ui-icon-arrowreturnthick-1-e">
                        <p:submenu label="User Management" icon="ui-icon-arrowreturnthick-1-e">
                            <p:menuitem value="Full Report" url="/secured/report/reportList.xhtml" icon="ui-icon-arrowreturnthick-1-e" />
                            <p:menuitem value="Generate Report" url="/secured/report/generateReport.xhtml" icon="ui-icon-arrowreturnthick-1-e"  />
                        </p:submenu>
                        <p:submenu label="Service Management" icon="ui-icon-arrowreturnthick-1-e">
                            <p:menuitem value="Full Report" url="/secured/report/reportList.xhtml" icon="ui-icon-arrowreturnthick-1-e" />
                            <p:menuitem value="Generate Report" url="/secured/report/generateReport.xhtml" icon="ui-icon-arrowreturnthick-1-e"  />
                        </p:submenu>
                    </p:submenu>
             <p:menu  model="#{menuModelBean.model}">
             </p:menu>
          </p:menubar>
      </h:form>

}

这是错误。我正在使用primeface 5.1。

    package com.bat.qpa.beans;

    import javax.annotation.PostConstruct;
    import javax.faces.application.FacesMessage;
    import javax.faces.bean.ManagedBean;
    import javax.faces.context.FacesContext;
    import org.primefaces.model.menu.DefaultMenuItem;
    import org.primefaces.model.menu.DefaultMenuModel;
    import org.primefaces.model.menu.DefaultSubMenu;
    import org.primefaces.model.menu.MenuModel;

    @ManagedBean(name = "menuModelBean")
    public class MenuModelBean {

private MenuModel model = new DefaultMenuModel();

@PostConstruct
public void init() {
    model = new DefaultMenuModel();

    //First submenu
    DefaultSubMenu firstSubmenu = new DefaultSubMenu("Dynamic Submenu");

    DefaultMenuItem item = new DefaultMenuItem("External");
    item.setUrl("http://www.primefaces.org");
    item.setIcon("ui-icon-home");
    firstSubmenu.addElement(item);

    model.addElement(firstSubmenu);

    //Second submenu
    DefaultSubMenu secondSubmenu = new DefaultSubMenu("Dynamic Actions");

    item = new DefaultMenuItem("Save");
    item.setIcon("ui-icon-disk");
    item.setCommand("#{menuView.save}");
    item.setUpdate("messages");
    secondSubmenu.addElement(item);

    item = new DefaultMenuItem("Delete");
    item.setIcon("ui-icon-close");
    item.setCommand("#{menuView.delete}");
    item.setAjax(false);
    secondSubmenu.addElement(item);

    item = new DefaultMenuItem("Redirect");
    item.setIcon("ui-icon-search");
    item.setCommand("#{menuView.redirect}");
    secondSubmenu.addElement(item);

    model.addElement(secondSubmenu);
}

public MenuModel getModel() {
    return model;
}

public void setModel(MenuModel model) {
    this.model = model;
}


public String openAction() {
    FacesContext.getCurrentInstance().addMessage(null, new FacesMessage("Open action has activiated asynchrounsly !"));
    return "";
}

我想使用托管bean创建一个Programmatic菜单。第一部分是我的xhtml页面，第二部分是Managed Bean，第三部分是error.I已搜索，但我找不到这样的任何错误。 我在Primefaces网站演示中遵循的方式。但得到错误。为什么呢？