spring 2.5.6 DI issue in jsf application - spring

Question

i get NPE(null pointer exception) each time when i try to insert data into database. help me to resolve this issue. i have import all the necessary libraries which are requried for spring.
this is my applicationContext.xml file where i have configure all the beans.
<?xml version="1.0" encoding="UTF-8"?>
<beans xmlns="http://www.springframework.org/schema/beans"
xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"
xsi:schemaLocation="http://www.springframework.org/schema/beans
http://www.springframework.org/schema/beans/spring-beans-2.5.xsd">
<bean id="personService" class="com.ecommerce.assignment.service.PersonService">
<property name="personDAO" ref="personDAO" />
</bean>
<bean id="personBean" class="com.ecommerce.assignment.bean.PersonBean" />
<bean id="personDAO" class="com.ecommerce.assignment.dao.PersonDAO" />
</beans>
this is interface of person DAO.
public interface IPersonDAO {
public void addPerson(Person instance);
}
this personDAO class implementing IpersonDAO interface and its unimplemented methods.
public class PersonDAO implements IPersonDAO {
#Override
public void addPerson(Person instance) {
Session session = HibernateUtil.getSessionFactory().openSession();
session.beginTransaction().begin();
session.saveOrUpdate(instance);
session.getTransaction().commit();
session.close();
}
}
this is interface personService.
public interface IPersonService {
public void addPerson(Person instance);
}
public class PersonService implements IPersonService,Serializable {
private IPersonDAO personDAO;
public IPersonDAO getPersonDAO() {
return personDAO;
}
public void setPersonDAO(IPersonDAO personDAO) {
this.personDAO = personDAO;
}
#Override
public void addPerson(Person instance) {
getPersonDAO().addPerson(instance);
}
}
public class PersonBean implements Serializable {
private static final long serialVersionUID = 1L;
private String emailAddress;
private String password;
private String username;
#ManagedProperty(value = "#{personService}")
private IPersonService iPersonService;
public void addPerson(){
try{
Person person = new Person();
person.setUsername(getUsername());
person.setEmailAddress(getEmailAddress());
person.setPassword(getPassword());
iPersonService.addPerson(person);
}
catch(Exception ex){
ex.printStackTrace();
}
}
}

Answer 1

As your person bean is managed by Spring, you should use #Autowired annotation to make dependency injection, or inject it via XML, as you did for PersonService. You can as well declare the bean as #Component and #Scope.
You error is in injecting service in a bean by using JSF's #ManagedProperty annotation that works solely within JSF context, that is, with JSF managed beans, annotated with #ManagedBean, or declared via XML.