@Entity
@RooEntity
@NamedNativeQuery(name="Mileage.calculateMileage",
      query = "{ call logobj.milookup(?,?,?) }",
      hints = {
         @QueryHint(name = "org.hibernate.callable", value = "true"),
         @QueryHint(name = "org.hibernate.readOnly", value = "true")
      },
      resultClass = MileageTest.class)
public class MileageTest {
   private static Log log = LogFactory.getLog(MileageTest.class);
   
   @Column(name = "PMMILES")
   private String miles;

   @Test
   public void calculateMileage() {
      Map<String,String> args = new HashMap<String,String>();
                // args values are set here.
      
      EntityManagerFactory emf = Persistence.createEntityManagerFactory("persistenceUnit", args);
      EntityManager em = emf.createEntityManager();
      
      Query query = em.createNamedQuery("Mileage.calculateMileage");
      
      query.setParameter(2, "TORONTO                       ON");
      query.setParameter(3, "MONTREAL                      QC");
      
      if(log.isInfoEnabled())
         log.info(query.getResultList());
   }
}