The method nullSafeGet appears to not be null-safe since
JGeometry.load(null) throws an Exception.  I think resultSet.wasNull()
should be checked sooner, like this:

    public Object nullSafeGet( ResultSet resultSet, String[] strings,
Object o) throws HibernateException, SQLException {
      STRUCT geometry = (STRUCT) resultSet.getObject( strings[0]);
      if (resultSet.wasNull()) { return null; }
      JGeometry jg = JGeometry.load( geometry);
      return new JGeometryType( jg);
    }

-Ash