public class QuestionsDAO implements DAOInterface {
    private Session session = HibernateUtil.getSessionFactory().openSession();

    @Override
    public void addObj(Object obj) throws SQLException {
        try {
            session.beginTransaction();
            session.save(obj);
            session.getTransaction().commit();
        } catch (Exception e) {
            System.err.println(e.getMessage() + "\nОшибка при QuestionsDAO::addObj(Object obj)");
        } 
    }

    @Override
    public void updateObj(Object obj) throws SQLException {
        try {
            session.beginTransaction();
            session.update(obj);
            session.getTransaction().commit();
        } catch (Exception e) {
            System.err.println(e.getMessage() + "\nОшибка при QuestionsDAO::updateObj(Object obj)");
        } 
    }


    @Override
    public Questions getObjById(Long obj_id) throws SQLException {
        Questions qst = null;
        try {
            qst = (Questions) session.load(Questions.class, obj_id);
        } catch (Exception e) {
            System.err.println(e.getMessage() + "\nОшибка при QuestionsDAO::getObjById");
        }
        return qst;
    }

    @Override
    public Collection getAllObj() throws SQLException {
        List qsts = new ArrayList<Questions>();
        try {
            qsts = session.createCriteria(Questions.class).list();
        } catch (Exception e) {
            System.err.println(e.getMessage() + "\nОшибка при  QuestionsDAO::getAllObj()");
        } 
        return qsts;
    }

    @Override
    public void deleteObj(Object obj) throws SQLException {
        try {
            session.beginTransaction();
            session.delete(obj);
            session.getTransaction().commit();
        } catch (Exception e) {
            System.err.println(e.getMessage() + "\nОшибка при QuestionsDAO::deleteObj(Object obj)");
        }  
    }
}