0 Replies Latest reply on Mar 22, 2008 3:38 PM by Davy De Winter

    Implementing business-logic: ConcurrentModificationException

    Davy De Winter Newbie

      Hi all,

      I use a stateless session-bean to implement the business-logic to save entity-beans. The stateless session-bean uses injection of the entitymanager as follows:

      @Stateless(mappedName = "PersonDAO")
      public class PersonDAO extends DAOBasicOperationsAbstractClass<Person> implements PersonDAOInterfaceLocal, PersonDAOInterfaceRemote{
       @PersistenceContext(unitName = "texaco", type = PersistenceContextType.TRANSACTION)
       EntityManager em;
      


      Before saving the "Person"-entitybean, I'd like to do some checks by executing a native read-query in a separate method on the same table (join with other ones) where I'd like to save the Person:

       Query query=em.createNativeQuery(
       querystring
       );
      
       query.setParameter("TELEPHONENUMBER_1", person.getPhonenumber1()==null?"K":person.getPhonenumber1().getPhoneNumber());
       query.setParameter("TELEPHONENUMBER_2", person.getPhonenumber2()==null?"K":person.getPhonenumber2().getPhoneNumber());
       query.setParameter("GSMNUMBER_1", person.getGsmnumber1()==null?"K":person.getGsmnumber1().getPhoneNumber());
       query.setParameter("GSMNUMBER_2", person.getGsmnumber2()==null?"K":person.getGsmnumber2().getPhoneNumber());
       if (update) query.setParameter("ID", person.getId());
       Collection<Person> pers_coll=executeMultipleResultQuery(query);
       if (pers_coll.size()>0) return false;
       else return true;
      


      If this method returns
      true
      , the new person will not be saved, otherwise he will be saved as follows:

       if (!checkPhoneNumberValidity(person, true)) throw new PersonValidationException();
       Person person_orig=findById(person.getId());
       if (!person_orig.equals(person)){
       person_orig.getLatestValidPersonProperty().getValidityinterval().invalidate();
       person.getLatestValidPersonProperty().setValidityinterval(new ValidityInterval(new GregorianCalendar(), new GregorianCalendar(2099, 12, 12)));
       person.getLatestValidPersonProperty().setId(null);
       person_orig.getPersonproperties().add(person.getLatestValidPersonProperty());
       person_orig.setName(person.getName());
       person_orig.setFirstname(person.getFirstname());
       person_orig.setNationalregisternumber(person.getNationalregisternumber());
       person_orig.setIdentitycardnumber(person.getIdentitycardnumber());
       person_orig.setBirthdate(person.getBirthdate());
       person_orig.setSex(person.getSex());
       person_orig.deepValidate();
       executeMerge(em, person_orig);
       }
      


      Please note, I also make some comparisons with the original object as I work with properties. In this scenario, I get a ConcurrentModificationException. Seems logic to me, but how to solve this in a proper way, because the checks must happen within the same transaction.

      Any help or advice is very appreciated!

      Best regards,
      Davy.