conn.setAutoCommit(false);
try {
            stmt2 = conn.createStatement(ResultSet.TYPE_SCROLL_INSENSITIVE, ResultSet.CONCUR_UPDATABLE);
            ResultSet res = stmt2.executeQuery("SELECT id,type,name,data FROM super_features WHERE chart_id = "+chart_id+" for update");
            while (res.next()) {
                for (FeatureItem item : items) {
                    if (item.getId() == res.getInt(1)) {
                        res.updateInt(2, item.getType());
                        res.updateString(3, item.getName());
                        res.updateString(4, item.getData());
                        res.updateRow();
                        break;
                    }
                }
            }

            res.close();
            stmt2.close();
            conn.commit();
            conn.close();
        } catch (SQLException e) { System.err.println("Error updating features"); throw e; }
        finally { try{conn.close();}catch(Exception e){} }