JSF dataTable and fileUpload (fileupload issue) - jsf

Question

Please let me know your suggestion. I want to build fileUpload with specific design and having issue with getting hold of the uploadedFile.
My design:
DataModel class:
#Named
#SessionScoped
public class NJDataModel implements Serializable {
private static final long serialVersionUID = 1L;
private String sectionName;
private UploadedFile file;
public NJDataModel(String sectionName) {
this.sectionName = sectionName;
}
public String getSectionName() {
return sectionName;
}
public void setSectionName(String sectionName) {
this.sectionName = sectionName;
}
public UploadedFile getFile() {
return file;
}
public void setFile(UploadedFile file) {
this.file = file;
}
}
Data class:
#ManagedBean(name = "NJData")
#SessionScoped
public class Data implements Serializable {
private static final long serialVersionUID = 1L;
private List<NJDataModel> dataModel;
#PostConstruct
public void init() {
/** defaults */
dataModel = new ArrayList<NJDataModel>();
dataModel.add(new NJDataModel("Title page"));
}
public void upload() {
System.out.println("upload method triggered");
String msg = null;
for (NJDataModel i : dataModel) {
UploadedFile file = i.getFile();
// ERROR: file is always null? so could not get hold of file
if (file != null) {
System.out.println("Uploaded file:" + file.getFileName());
msg += "file:" + file.getFileName() + "size:" + file.getSize() + ", ";
}
}
FacesContext.getCurrentInstance().addMessage(null, new FacesMessage(msg));
}
}
XHTML:
<p:dataTable var="item" value="#{NJData.dataModel}"
draggableColumns="true">
<p:column>
<p:panel>
<f:facet name="header">
<h:outputText value="#{item.sectionName}" />
</f:facet>
<p:fileUpload value="#{item.file}" mode="simple" />
</p:panel>
</p:column>
</p:dataTable>
<p:commandButton value="Submit" ajax="false"
actionListener="#{NJData.upload}" />
And finally, i need to get hold of file in method: NJData.upload() - where i always get null?
My console output:
file object:null & section name:first page
file object:null & section name:second page