How to set and get viewparameter in jsf? - jsf

Question

Im trying to send data from one jsf page to another, but without success.
firstPage.xhtml
<h:form>
<p:dataTable id="dataList" value="#{firstBean.dataList}" var="data">
<p:column>
<f:facet name="header">Column 1</f:facet>
#{data.column1.id}
</p:column>
<p:column>
<f:facet name="header" >Column 2</f:facet>
#{data.colum2.name}
</p:column>
<p:column>
<f:facet name="header" >Detail Row</f:facet>
<!-- I need this button send me to another page where i will detail information about an certain id -->
<h:commandButton value="Detalhar" action="#{firstBean.someMethod}">
<f:param name="dataId" value="#{data.column1.id}"/>
</h:commandButton>
</p:column>
</p:dataTable>
</h:form>
First Bean
#ManagedBean
#ViewScoped
public class FirstBean implements Serializable{
private static final long serialVersionUID = 1L;
//list with some data
private List<Data> dataList; //getter setter
#EJB
MyDataManager manager;
#PostConstruct
public void init() {
dataList = manager.getDataList();
}
public void someMethod() throws IOException {
//do something
FacesContext.getCurrentInstance().getExternalContext().redirect("secondPage.xhtml");
}
}
secondPage.xhtml
<h:body>
<f:metadata>
<f:viewParam name="dataId" value="#{secondBean.dataDetailId}" />
<f:viewAction action="#{secondBean.init}" />
</f:metadata>
<p:dataTable value="#{secondBean.dataDetailList}" var="dataDetail">
<p:column>
<f:facet name="header">Data Detail 1</f:facet>
#{dataDetail.data1}
</p:column>
<p:column>
<f:facet name="header">Data Detail 2</f:facet>
#{dataDetail.data2}
</p:column>
<p:column>
<f:facet name="header">Data Detail 3</f:facet>
#{dataDetail.data3}
</p:column>
</p:dataTable>
</h:body>
Second Bean
#ManagedBean
#ViewScoped
public class CarteiraDetalheBean implements Serializable{
private static final long serialVersionUID = 1L;
private Integer dataId; //getter setter
private List<DataDetail> dataDetailList; //getter setter
#EJB
MyDataManager manager;
#PostConstruct
public void init() {
dataDetailList = manager.getDataDetail(dataId);
}
}
When i use:
<f:viewAction action="#{secondBean.init}" />
I gotthe message: The metadata component needs to be nested within a f:metadata tag. Suggestion: enclose the necessary components within
and when i use:
<f:event type="preRenderView" listener="#{secondBean.init()}" />
i got a null pointer exception in line:
dataDetailList = manager.getDataDetail(dataId);
What im doing wrong?