losing request parameter in jsf for second ajax poll call - ajax

Question

I'm facing a problem with poll request, the first call is ok and the second is loosing the request parameter. Below is the code:
<h:form id="form">
<p:poll interval="10" listener="${emsstatbean.getEmsStat_list(request.getParameter('para'))}" update="emstatTable" />
<p:dataTable id="emstatTable" var="emsstat" value="${emsstatbean.getEmsStat_list(request.getParameter('para'))}" emptyMessage="No statistic found with given criteria" styleClass="table table-striped table-bordered table-hover" >
<p:column headerText="Server Hostname" >
<h:outputText value="#{emsstat.id.timeStamp}" />
</p:column>
<p:column headerText="Os name" >
<h:outputText value="#{emsstat.upTime}" />
</p:column>
<p:column headerText="Os name" >
<h:outputText value="${emsstat.state}" />
</p:column>
</p:dataTable>
</h:form>
and this is the bean class:
#ManagedBean(name = "emsstatbean")
public class EmsStatBean implements Serializable
{
public List<TibcoEmsStat> getEmsStat_list(int p)
{
return service.listEmsStats(p);
}
#ManagedProperty("#{emsStatService}")
EmsStatService service;
#PostConstruct
public void init()
{
}
public void setService(EmsStatService service)
{
this.service = service;
}
}
This is the URL called: content/public/TibcoEmsStat.xhtml?para=254
So when I paste that on browsers I'm getting the data table with all rows, but when I wait 10 sec I don't see content and I get "No statistic" found with given criteria, because parameter is empty.
Can you please help me to understand where is the issue?

Answer 1

this is how i fixed after reviewing some suggested link
added to the bean:
#ViewScoped
and a variable to store the id
public int ems_inst;
public int getEms_inst() {
return ems_inst;
}
public void setEms_inst(int ems_inst) {
this.ems_inst = ems_inst;
}
on the xhtml i did:
<f:metadata>
<f:viewParam name="ems_inst" value="#{emsstatbean.ems_inst}" />
</f:metadata>
<h:form id="form">
<p:poll interval="10"
listener="${emsstatbean.getEmsStat_list(emsstatbean.ems_inst)}" update="emstatTable" />
<p:dataTable id="emstatTable" var="emsstat" value="${emsstatbean.getEmsStat_list(emsstatbean.ems_inst)}"
all now is working fine
thanks