sorting not working in p:datatable - jsf

Question

I am using primeface datatable but its sorting not working, can anyone help me!! I have tried to add #{v.elementID} in sortBy but it still not workin
<p:dataTable value="#{dashboardBean.topTenMenuItem}"
var="v" paginator="true"
rows="#{msg['dashboard.product.mapping.datatable.rows']}">
<p:column sortBy="#{v.elementId}" headerText="ID">
<h:outputText value="#{v.elementId}" />
</p:column>
<p:column sortBy="#{v.name}" headerText="Name">
<h:link value="#{v.name}" />
</p:column>
<p:column sortBy="#{v.updateBy}" headerText="Update By">
<h:outputText value="#{v.updateBy}" />
</p:column>
<p:column sortBy="#{v.statusName}" headerText="Status">
<h:outputText value="#{v.statusName}" />
</p:column>
<p:column sortBy="#{v.updateDate}" headerText="Updated On">
<h:outputText value="#{v.updateDate}" />
</p:column>
</p:dataTable>
and bean is
public List<RecentItemDashDTO> getTopTenMenuItem() {
Map<String, Object> sessMap = CommonUtil.getSessionMap();
SessionDTO sessionDTO = (SessionDTO) sessMap.get(WebConstants.SESSION_DTO);
countryCode = sessionDTO.getLoggedinCountryCode();
String languageCode = sessionDTO.getDefaultLanguageCode();
topTenMenuItem = dashboardService.getTopTenRecentMenuDashData(countryCode,languageCode);
return topTenMenuItem;
}
public void setTopTenMenuItem(List<RecentItemDashDTO> topTenMenuItem) {
this.topTenMenuItem = topTenMenuItem;
}

Answer 1

My own experience says that to use this feature you'll need a List object in your BackingBean, with getters and setters. Not a reference. Try that with any init method and let us know if it worked.
public class DashboardBean {
private List<RecentItemDashDTO> myList;
public List<RecentItemDashDTO> getMyList()
{
return myList;
}
public void setMyList(List<RecentItemDashDTO> myList)
{
this.myList = myList;
}
public List<RecentItemDashDTO> getTopTenMenuItem()
{
Map<String, Object> sessMap = CommonUtil.getSessionMap();
SessionDTO sessionDTO = (SessionDTO)sessMap.get(WebConstants.SESSION_DTO);
countryCode = sessionDTO.getLoggedinCountryCode();
String languageCode = sessionDTO.getDefaultLanguageCode();
topTenMenuItem = dashboardService.getTopTenRecentMenuDashData(countryCode, languageCode);
return topTenMenuItem;
}
#PostConstruct
public void init()
{
myList = getTopTenMenuItem();
}
}
XHTML:
<p:dataTable value="#{dashboardBean.myList}" ... >

Answer 2

I got another solution for sorting.
private String initList;
public String getInitList() {
myTopTenMenuItem=getTopTenMenuItem();
return null;
}
and in xhtml
<h:form name="form" prependId="false">
<h:inputHidden value="#{dashboardBean.initList}" />