if (!opened) throw new FBSQLException(
if (isBeforeFirst() || isAfterLast()) throw new FBSQLException(
    private FBField getField(int columnIndex) throws SQLException {        if (closed) throw new FBSQLException("The resultSet is closed");        if (!opened) throw new FBSQLException(                    "The resultSet is not in a row, use next",                    FBSQLException.SQL_STATE_NO_ROW_AVAIL);                if (columnIndex> xsqlvars.length)             throw new FBSQLException(                    "Invalid column index.",                    FBSQLException.SQL_STATE_INVALID_COLUMN);                FBField field = fields[columnIndex-1];        wasNullValid = true;        wasNull = field.isNull();        return field;    }