this:
public void persist(E entity) {
entityManager.persist(entity); ** this line
}
thanks for your answer
2013/2/20 Rick Curtis <[email protected]>
> What is at com.caf.db.dao.JpaDao.persist(JpaDao.java:20)?
>
>
> On Tue, Feb 19, 2013 at 5:08 PM, Aitor Iturriondobeitia <
> [email protected]> 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*
>
