#Inject PersonDao is null in #FacesConverter class [duplicate] - jsf

Question

This question already has answers here:
How to inject #EJB, #PersistenceContext, #Inject, #Autowired, etc in #FacesConverter?
(5 answers)
Closed 7 years ago.
I am trying to get from selectOneMenu an object that has fields such as first name, last name and so on. This is my form:
<h:form>
<p:outputLabel value="Persons: " />
<p:selectOneMenu value="#{personBean.person}">
<f:selectItem itemLabel="Select Person" itemValue="" noSelectionOption="true"/>
<f:selectItems itemLabel="#{person.firstName}" itemValue="#{person}" var="person" value="#{personBean.persons}" />
</p:selectOneMenu>
<br /><br />
<p:commandButton value="Submit"
action="#{personBean.showSomething()}" icon="ui-icon-check" />
I don't understand.. where am i going wrong? How can i get that object?
I've been trying for a few days but i haven't managed to fix this problem...
I tried using a Converter but i kept getting NPEs.
EDIT
This is my converter:(I am trying to get the object from my postgres db with the help of my DAO)
#Named
#FacesConverter(forClass=Person.class)
public class PersonConverter implements Converter {
#Inject
private PersonDao personDao;
#Override
public Object getAsObject(FacesContext arg0, UIComponent component, String submittedValue) {
if (submittedValue == null || submittedValue.isEmpty()) {
return null;
}
try {
Person p = personDao.findById(Long.valueOf(submittedValue));
return p;
} catch (NumberFormatException e) {
throw new ConverterException(new FacesMessage(submittedValue + " is not a valid Person ID"), e);
}
}
#Override
public String getAsString(FacesContext arg0, UIComponent arg1, Object arg2) {
if (arg2 == null) {
return "";
}
if (arg2 instanceof Person) {
return String.valueOf(((Person) arg2).getId());
} else {
throw new ConverterException(new FacesMessage(arg2 + " is not a valid Person"));
}
}
}
This is where i get a NPE Person p = personDao.findById(Long.valueOf(submittedValue));
The find() method works anywhere else...
When i used the debugger i noticed that personDao is null. How can i fix this?

Answer 1

In the page:
<p:selectOneMenu value="#{personBean.person}">
<f:selectItem itemLabel="Select Person" itemValue="" noSelectionOption="true"/>
<f:selectItems itemLabel="#{person.firstName}" itemValue="#{person}" var="person" value="#{personBean.persons}" />
<f:converter binding="#{personConverter}" />
<f:attribute name="attrpersons" value="#{personBean.persons}" />
</p:selectOneMenu>
In the Person bean:
You must implement toString and equals methods.
And finally you have to add the converter class:
#Named
public class PersonConverter implements Converter{
public PersonConverter(){}
#Override
public Object getAsObject(FacesContext facesContext, UIComponent component, String submittedValue) {
List<Person> persons = (List<Person>)component.getAttributes().get("attrpersons");
if (submittedValue.trim().equals("")) {
return null;
} else {
Iterator<Person> it = persons.iterator();
while(it.hasNext()){
Person p = it.next();
if(p.toString().equals(submittedValue))
return p;
}
}
return null;
}
#Override
public String getAsString(FacesContext facesContext, UIComponent component, Object value) {
if (value == null) {
return "";
} else {
return value.toString();
}
}
}