Just a part. I have a JEE aplication and I would like to split the
persistence part from my JPA class. Do you have some idea? I will take a
look on the documentation.
2009/10/22 Marina Vatkina <Marina.Vatkina_at_sun.com>
> It depends on what you are trying to achieve in which type of an
> application. Did you look at the JPA cjapter in Java EE 5 Tutorial?
>
> Roan Brasil Monteiro wrote:
>
>> How should I resolve it? How should be my class? I am learning and I am
>> trying to put the persistence part in DAO class.
>>
>> 2009/10/22 Marina Vatkina <Marina.Vatkina_at_sun.com <mailto:
>> Marina.Vatkina_at_sun.com>>
>>
>>
>> You can't inject anything in a class that is neither a Main class,
>> nor a JavaEE component.
>>
>> -marina
>>
>>
>> Roan Brasil Monteiro wrote:
>>
>> I have a class BaseDAO as bellow and I am getting
>> NullPointerException on EntityManager em =
>> emf.createEntityManager(); line from BaseDAO class, Can someone
>> help me how to fix it?
>>
>> public class BaseDAO<T> {
>>
>> @PersistenceUnit(unitName = "citespacePU")
>> EntityManagerFactory emf;
>> public List<T> ListCountry(){
>> EntityManager em = emf.createEntityManager();
>> try{
>> Query q = em.createQuery("Select c from Country c ");
>> List<Country> c = q.getResultList();
>> return (List<T>) c;
>> }finally{
>> if (em != null && em.isOpen()) {
>> em.close();
>> }
>> } }
>>
>>
>> }
>>
>> I have my Jersey resource class:
>>
>> @Path("/user/")
>> public class UserResource {
>> @GET
>> @Produces("text/plain")
>> public String registerUser(){
>> BaseDAO<Country> countryDAO = new
>> BaseDAO<Country>();
>> List<Country> c = countryDAO.ListCountry();
>> String y = "";
>> for(Country x: c){
>> y = y + ":" +x.getName();
>> }
>> return "[Country List]:"+y;
>>
>> }
>>
>> -- Atenciosamente,
>>
>> Roan Brasil Monteiro
>> http://roanbrasil.wordpress.com/
>>
>>
>>
>>
>>
>> --
>> Atenciosamente,
>>
>> Roan Brasil Monteiro
>> http://roanbrasil.wordpress.com/
>>
>
>
--
Atenciosamente,
Roan Brasil Monteiro
http://roanbrasil.wordpress.com/