HibernateCallback 的用法

public Integer obtenerTamanho(final Busqueda filtro){
  return (Integer)this.getHibernateTemplate().execute(new HibernateCallback(){
    @Override public Object doInHibernate(    Session session) throws HibernateException, SQLException {
      Projection total=Projections.rowCount();
      filtro.setProjection(total);
      Integer resultado=(Integer)filtro.getExecutableCriteria(session).uniqueResult();
      filtro.setProjection(null);
      return resultado;
    }
  }
);
}

@SuppressWarnings("unchecked") private int getNumberOfRecords(){
  @SuppressWarnings("rawtypes") Long count=(Long)_dao.getHibernateTemplate().execute(new HibernateCallback(){
    public Object doInHibernate(    Session session) throws HibernateException {
      Query query=session.createQuery("select count(*) from ArchivedInferredLocationRecord");
      return (Long)query.uniqueResult();
    }
  }
);
  return count.intValue();
}