package net.helipilot50.stocktrade.server.dao;
import java.lang.reflect.ParameterizedType;
import java.util.List;
import javax.persistence.EntityManager;
import javax.persistence.PersistenceException;
import javax.persistence.Query;
import org.springframework.orm.jpa.JpaCallback;
import org.springframework.orm.jpa.support.JpaDaoSupport;
public abstract class JpaDAO<K, E> extends JpaDaoSupport {
protected Class<E> entityClass;
@SuppressWarnings("unchecked")
public JpaDAO() {
ParameterizedType genericSuperclass = (ParameterizedType) getClass()
.getGenericSuperclass();
this.entityClass = (Class<E>) genericSuperclass
.getActualTypeArguments()[1];
}
public void persist(E entity) {
getJpaTemplate().persist(entity);
}
public void remove(E entity) {
getJpaTemplate().remove(entity);
}
public E merge(E entity) {
return getJpaTemplate().merge(entity);
}
public void refresh(E entity) {
getJpaTemplate().refresh(entity);
}
public E findById(K id) {
return getJpaTemplate().find(entityClass, id);
}
public E flush(E entity) {
getJpaTemplate().flush();
return entity;
}
@SuppressWarnings("unchecked")
public List<E> findAll() {
Object res = getJpaTemplate().execute(new JpaCallback() {
public Object doInJpa(EntityManager em) throws PersistenceException {
Query q = em.createQuery("SELECT h FROM " +
entityClass.getName() + " h");
return q.getResultList();
}
});
return (List<E>) res;
}
@SuppressWarnings("unchecked")
public Integer removeAll() {
return (Integer) getJpaTemplate().execute(new JpaCallback() {
public Object doInJpa(EntityManager em) throws PersistenceException {
Query q = em.createQuery("DELETE FROM " +
entityClass.getName() + " h");
return q.executeUpdate();
}
});
}
}