Injecting DAO give NullPointerException - jsf

Question

Using the following Bean, I fill a form with countries:
#ManagedBean
#RequestScoped
public class CreateUser {
#EJB
private ParticipantDAO participantDAO;
#EJB
private CountryDAO countryDAO;
private List<Country> countries = new ArrayList<Country>();
. . .
. . .
. . .
#PostConstruct
public void init() {
countries = countryDAO.getAllCountries();
}
In the form I've to use a Converter:
<h:selectOneMenu id="country" value="#{createUser.user.country}" required="true" requiredMessage="Please select a country." converter="#{countryConverter}" >
<f:selectItem itemValue="#{null}" itemLabel="-- select one --" />
<f:selectItems value="#{createUser.countries}" var="country" itemValue="#{country}" itemLabel="#{country.country}" />
</h:selectOneMenu>
The Converter give a NullPointerException seems because it's unable to inject CountryDAO:
#ManagedBean
#RequestScoped
#FacesConverter(forClass = Country.class)
public class CountryConverter implements Converter {
#EJB
private CountryDAO countryDAO;
#Override
public String getAsString(FacesContext context, UIComponent component, Object value) {
if (!(value instanceof Country)) {
return null;
}
return String.valueOf(((Country) value).getId());
}
#Override
public Object getAsObject(FacesContext context, UIComponent component, String value) {
if (value == null || value.isEmpty()) {
return null;
}
try {
System.out.println("Converter Value: " + value);
Country c = countryDAO.find(Long.valueOf(value));
System.out.println("Converter: " + c.getCountry());
return c;
} catch (Exception e) {
throw new ConverterException(new FacesMessage(String.format("Cannot convert %s to Country %s %d", value, e.toString(), Long.valueOf((value)))), e);
}
}
}
In the console I see the "Converted Value" message but not the "CountryDAO find" that should be printed by createDAO.find method.
#Stateless
#LocalBean
public class CountryDAO {
public CountryDAO() {
}
#PersistenceContext
private EntityManager em;
#Resource
SessionContext context;
public List<Country> getAllCountries() {
TypedQuery<Country> query = em.createNamedQuery(Country.FIND_ALL, Country.class);
return query.getResultList();
}
public Country find(Long id) {
System.out.println("CountryDAO find");
Country c = em.find(Country.class, id);
System.out.println(c.getCountry());
return c;
}
I tried the solution reported to Inject a EJB into a JSF converter with JEE6 (I don't know if I put the code in the correct location). I put it in the converter (and I obtain the NullPointerException):
#ManagedBean
#FacesConverter(forClass = Country.class)
public class CountryConverter implements Converter {
// #EJB
// private CountryDAO countryDAO;
private InitialContext ic;
private CountryDAO countryDAO;
#Override
public String getAsString(FacesContext context, UIComponent component, Object value) {
if (!(value instanceof Country)) {
return null;
}
return String.valueOf(((Country) value).getId());
}
#Override
public Object getAsObject(FacesContext context, UIComponent component, String value) {
if (value == null || value.isEmpty()) {
return null;
}
System.out.println("Converter Value: " + value);
try {
try {
ic = new InitialContext();
countryDAO = (CountryDAO) ic.lookup("java:global/DAO/CountryDAO");
} catch (NamingException e) {
}
Country c = countryDAO.find(Long.valueOf(value));
System.out.println("Converter: " + c.getCountry());
return c;
} catch (Exception e) {
throw new ConverterException(new FacesMessage(String.format("Cannot convert %s to Country %s %d", value, e.toString(), Long.valueOf((value)))), e);
}
}

Answer 1

I was having the same problem in the some other project, where I was using a converter for some primefaces component. I solved the problem the CDI way.
All you have to do is annotate your converter class with #Named (and inject the DAO class via #Inject (JEE6), and not with JEE5 - #EJB).
You reference your converter with binding attribute like:
<f:converter binding="#{countryConverter}" />