Persistencias de Modos Diferentes

VehicleService.java

@Service
public class VehicleServiceImpl implements VehicleService {

  @PersistenceContext
  EntityManager em;

  /**
   * O(1)
   */
  @Override
  @Transactional
  public void addVehicle(Vehicle vehicle) {
    em.persist(vehicle);
  }

  // other method omitted ..

  /**
   * O(n)
   */
  @Override
  @Transactional
  public List<Vehicle> findVehicleByBrand(String column, String order) {
    return em.createNativeQuery(
        "select * from vehicle as v where v." + column.toLowerCase() + " = '"
            + column + "' order by " + column.toLowerCase() + " " + order)
        .getResultList();
  }

  // other method omitted ..

  /**
   * O(n)
   */
  @Override
  @Transactional
  public List<Vehicle> findVehicles() {
    CriteriaQuery<Vehicle> c = em.getCriteriaBuilder().createQuery(
        Vehicle.class);
    // c.from(Vehicle.class);
    Root<Vehicle> from = c.from(Vehicle.class);
    c.orderBy(em.getCriteriaBuilder().asc(from.get("brand")));
    return em.createQuery(c).getResultList();
  }
}