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From Aitor Iturriondobeitia <laudio.i...@gmail.com>
Subject Re: my fist openjpa porject / problem. help me please
Date Wed, 20 Feb 2013 07:50:23 GMT
this:
public void persist(E entity) {
 entityManager.persist(entity); ** this line
}

thanks for your answer


2013/2/20 Rick Curtis <curtisr7@gmail.com>

> What is at com.caf.db.dao.JpaDao.persist(JpaDao.java:20)?
>
>
> On Tue, Feb 19, 2013 at 5:08 PM, Aitor Iturriondobeitia <
> laudio.info@gmail.com> wrote:
>
> > hello
> > i an tring to build my firts openjpa app
> > i am readint this article (
> > http://java.dzone.com/articles/jpa-implementation-patterns) and building
> > it
> > for this i make this:
> > 1.- generic interface:
> > public interface IGenericDao<K, E> {
> >  void persist(E entity);
> > }
> > 2.- other interface, my interface.
> > public interface IWsSrvTrackRequest  extends IGenericDao<Integer,
> > Wssrvtrackrequest>{
> >  void wsSrvRequestPersist(Wssrvtrackrequest request);
> > }
> > 3.- generic JPA-DAO:
> > public abstract class JpaDao<K, E> implements IGenericDao<K, E> {
> >  protected Class<E> entityClass;
> >
> >  @PersistenceContext
> >  protected EntityManager entityManager;
> >
> >  public JpaDao() {
> >   ParameterizedType genericSuperclass = (ParameterizedType)
> > getClass().getGenericSuperclass();
> >   this.entityClass = (Class<E>)
> > genericSuperclass.getActualTypeArguments()[1];
> >  }
> >  public void persist(E entity) {
> >   entityManager.persist(entity);
> >  }
> >  }
> > }
> > 4.- my jpa-dao implementation (the Wssrvtrackrequest obj is one jpa
> object
> > (entity)).
> > public class JpaWsSrvTrackRequestDaoImpl extends JpaDao<Integer,
> > Wssrvtrackrequest> implements IWsSrvTrackRequest {
> >  public void wsSrvRequestPersist(Wssrvtrackrequest request){
> >    entityManager.persist(request);
> >  }
> > }
> > i am make one main class:
> > public static void main(String[] args) {
> >   IWsSrvTrackRequest r = new JpaWsSrvTrackRequestDaoImpl();
> >   Wssrvtrackrequest v = new Wssrvtrackrequest();
> >   v.setWssrvreqIp("la ip");
> >   v.setWssrvreqOid("oid");
> >   v.setWssrvreqOiduser("oiduser");
> >   v.setWssrvreqRequest("la request");
> >   r.persist(v);
> >  }
> >
> >  but it always returns one nullpointerexception.
> >  Exception in thread "main" java.lang.NullPointerException
> >  at com.caf.db.dao.JpaDao.persist(JpaDao.java:20)
> >  at com.caf.db.dao.ll.main(ll.java:20)
> >
> >  Can you help me please?
> >
> >  thanks
> >
>
>
>
> --
> *Rick Curtis*
>

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