PreparedStatement 批量执行有遗漏么？解决方法

"select * from (select t.* ,rownum  row_num  from PAY_PREPAYMENT_WT_SEND t where REMAIN_MONTH <> 0 order by id desc) a where a.row_num>"                + start                + " and a.row_num <= "                + end;

SimpleDateFormat fmt = new SimpleDateFormat("yyyy-MM-dd HH:mm:ss");        PreparedStatement pstmt = null;        try {            conn.setAutoCommit(false);            pstmt =                conn.prepareStatement(                    "update PAY_PREPAYMENT_WT_SEND set REMAIN_MONTH = REMAIN_MONTH-1, LAST_UPDATE =?,COUNTNUM = COUNTNUM+1 WHERE id =?");            for (int i = 0; i < list.size(); i++) {                CTSHWTPayMentEntity pe = (CTSHWTPayMentEntity) list.get(i);                pstmt.setString(2, pe.getId());                pstmt.setTimestamp(                    1,                    Timestamp.valueOf(fmt.format(pe.getLast_update())));                pstmt.addBatch();            }            pstmt.executeBatch();            conn.commit();        } catch (SQLException e) {            try {                conn.rollback();            } catch (SQLException e1) {                e1.printStackTrace();            }            e.printStackTrace();        } finally {            try {                if (null != pstmt)                    pstmt.close();            } catch (SQLException e) {                e.printStackTrace();            }        }