Gestione delle transazioni in sospensione con DAO Design Pattern

Ho molte tabelle, per ogni tabella, abbiamo l'interfaccia DAO e la classe DAOImplementation.

Esempio di interfaccia DAO

public interface CancelPolicyDAO {

public CancelPolicy insertCancelPolicy(CancelPolicy cpdao)throws ChannelDispatcherException;

public CancelPolicy updateCancelPolicy(CancelPolicy cpdao)throws ChannelDispatcherException;

public void deleteCancelPolicy(CancelPolicy cpdao)throws ChannelDispatcherException;

public CancelPolicy findByCancelPolicyData(Integer id, Integer offSetUM, Integer nights, Float pOrAm, Byte isPercent)throws ChannelDispatcherException;

public CancelPolicy findByCancelPolicyId(Integer id)throws ChannelDispatcherException;
}

Esempio di classe di implementazione DAO

public class CancelPolicyDAOImpl implements CancelPolicyDAO {

@Override
public CancelPolicy insertCancelPolicy(CancelPolicy bean) throws ChannelDispatcherException {

    Session ses = null;
    try {

        ses = HibernateConnector.getInstance().getSession();
        ses.save(bean);
        ses.flush();
        return bean;
    } catch (Exception e) {
        e.printStackTrace();
        throw new ChannelDispatcherException(DbUtil.getStackTraceMessage(e));
    } finally {
        if (ses != null) {
            try {
                ses.close();
            } catch (Exception er) {
                er.printStackTrace();
            }
        }
    }

}

@Override
public CancelPolicy updateCancelPolicy(CancelPolicy bean) throws ChannelDispatcherException {
    Session sess = null;

    try {

        sess = HibernateConnector.getInstance().getSession();
        sess.update(bean);
        sess.flush();
        return bean;
    } catch (Exception e) {
      e.printStackTrace();
        throw new ChannelDispatcherException(DbUtil.getStackTraceMessage(e));
    }

}

@Override
public void deleteCancelPolicy(CancelPolicy bean) throws ChannelDispatcherException {
    Session sess = null;

    try {

        sess = HibernateConnector.getInstance().getSession();
        sess.delete(bean);
        sess.flush();
    } catch (Exception e) {
     e.printStackTrace();
        throw new ChannelDispatcherException(DbUtil.getStackTraceMessage(e));
    }

}

@Override
public CancelPolicy findByCancelPolicyData(Integer id, Integer offSetUM, Integer nights, Float pOrAm, Byte isPercent) throws ChannelDispatcherException {

    Session ses = null;
    try {
        ses = HibernateConnector.getInstance().getSession();
        Query query = ses.createQuery("from CancelPolicy a where "
                + " a.cancelPolicyTypeId =:cancelPolicyTypeId  "
                + " and   a.offsetUnitMultiplier =:offsetUnitMultiplier  "
                + " and   a.nights =:nights  "
                + " and   a.percentOramount =:percentOramount "
                + " and   a.isPercent =:isPercent");

        query.setParameter("cancelPolicyTypeId", id);
        query.setParameter("offsetUnitMultiplier", (offSetUM));
        query.setParameter("nights", (nights));
        query.setParameter("percentOramount", pOrAm);
        query.setParameter("isPercent", isPercent);

        List queryList = query.list();
        if (queryList != null && queryList.isEmpty()) {
            return null;
        } else {
            return (CancelPolicy) queryList.get(0);
        }
    } catch (Exception e) {
       e.printStackTrace();
        throw new ChannelDispatcherException(DbUtil.getStackTraceMessage(e));
    } finally {
        if (ses != null) {
            try {
                ses.close();
            } catch (Exception e) {
                e.printStackTrace();
            }
        }
    }

}

public CancelPolicy findByCancelPolicyId(Integer id) throws ChannelDispatcherException {

    Session ses = null;
    try {
        ses = HibernateConnector.getInstance().getSession();
        Query query = ses.createQuery("from CancelPolicy a where "
                + " a.id =:id  ");

        query.setParameter("id", id);

        List queryList = query.list();
        if (queryList != null && queryList.isEmpty()) {
            return null;
        } else {
            return (CancelPolicy) queryList.get(0);
        }
    } catch ( Exception e) {
       e.printStackTrace();
        throw new ChannelDispatcherException(DbUtil.getStackTraceMessage(e));
    } finally {
        if (ses != null) {
            try {
                ses.close();
            } catch (Exception e) {
                e.printStackTrace();
            }
        }
    }

}  

Esempio di metodo principale

 public static void main(String[] args)  {

       // How to handel Transaction in Hibernate ?
     CancelPolicyDAO cancelPolicyDAO = HibernateDAOFactory.getInstance().getCancelPolicyDAO();


     CancelPolicy insertCancelPolicy = cancelPolicyDAO.findByCancelPolicyData(2, 76, 25, 25.36f, 3);
    if(insertCancelPolicy==null){
        CancelPolicy cancelPolicy = new CancelPolicy();
    cancelPolicy.setCancelPolicyTypeId(1);
    cancelPolicy.setNights(2);
     insertCancelPolicy = cancelPolicyDAO.insertCancelPolicy(cancelPolicy);
    }
    Integer autoIncrementId = insertCancelPolicy.getId();

    AvailabilityDAO availabilityDAO =  HibernateDAOFactory.getInstance().getAvailabilityDAO();
    Availability availability = new Availability();
//        using  CancelPolicy autoIncrementId 
    availability.setId(autoIncrementId);
    availability.setCount(2);
    availability.setMaxLos(5);
    availabilityDAO.insertAvailability(availability);
    .
    .
    .
    .
    .


 }

Ora la mia domanda è: come gestisco la Transazione in DAOImpl?  Devo passare Session Object come parametro per ogni DAOImpl o c'è un approccio migliore