List<Object []> in JSF dataTable - jsf

Question

I have two entities , Employee and publication :
I want to show in a data table the publication title, date, and it's author stored in database :
this is my query using JPQL :
private static EntityManager em;
private static EntityManagerFactory factory;
public PublicationDAO() {
if(factory==null)
factory=Persistence.createEntityManagerFactory("mavenTest");
if(em==null)
em=factory.createEntityManager();
}
public List<Object[]> getAllPublication() {
em.getTransaction().begin();
List<Object[]> pubs = em.createQuery("SELECT c.titrePublication, p.login FROM Publication c JOIN c.employee p ").getResultList();
em.getTransaction().commit();
return pubs;
}
so I want to show this information in XHTML page's data table.

Answer 1

Currently the query would return Array and what you need is a Construct return type..
create custom class (this will be your return type and it must have constructor which takes result values you define in query string. )
public class publicationModel
{
public String publicationName;
public String author;
public publicationModel (String publicationName, String author)
{
this.publicationName= publicationName;
this.author= author;
}
}
use typedQuery
String queryStr ="SELECT NEW example.publicationModel (c.titrePublication, p.login) " +
"FROM Publication c JOIN c.employee p ";
TypedQuery query =
em.createQuery(queryStr, publicationModel .class);
List <publicationModel> results = query.getResultList();
m not able to format the answer.. but i hope this helps..

Answer 2

I wonder why you make the type of the list "array of objects". Rendering it as type of your entity class is enough :
public List<Publication> getAllPublication() {
...
List<Publication> pubs = ...
...
}
Specify a managedBean class in your presentation tier, to do the job :
#RequestScoped
#ManagedBean
public class PublicationBean {
// Inject your PublicationDAO here
private PublicationDAO publicationDao;
private List<Publication> publications;
#PostConstruct
public retrievePublications () {
try {
publications = publicationDao.getAllPublication();
} catch (Exception e) {
}
}
public List<Publication> getPublications() {
return this.publications;
}
public void setPublications(List<Publication> publications) {
this.publications= publications;
}
// getters/setters
}
Then, display the data with <h:dataTable> like this :
<h:dataTable value="#{publicationBean.publications}" var="p" rules="all">
<h:column>
<f:facet name="header">Publication title</f:facet>
#{p.titrePublication}
</h:column>
<h:column>
<f:facet name="header">Publication author</f:facet>
#{p.employee.name}
</h:column>
</h:dataTable>

Answer 3

hi finally I find the solution :
the correct query should be :
List<Publication>=em.createQuery("select p from Publication p",Publication.Class).getResultList();
in the managed bean I should declare The author which is The Employee entity with getter and setter.
then create a method called getAllpublications as :
public List<Publication> getAllpublications (){
publicationDao.getAllPublication();//this method is declared and specified in the DAO class
}
after that the xhtml page should look like:
<h:dataTable value="#{publicationBean.publications}" var="p" rules="all">
<h:column>
<f:facet name="header">Publication title</f:facet>
<h:outputText value="#{p.titrePublication}"></h:outputText>
</h:column>
<h:column>
<f:facet name="header">Publication author</f:facet>
<h:outputText value="#{p.employee.name}"></h:outputText>
</h:column>
</h:dataTable>
so the solution is very close to your answer Omar thanks a lot for your help.