StringBuffer xxe = new StringBuffer();
xxe.append("update stxxmskhk set xxe=? where stdm =?");
psupdate = conn.prepareStatement(xxe.toString());
psupdate.setCharacterStream(1, new StringReader(stxxmskhk.getXxe()),stxxmskhk.getXxe().length());
psupdate.setInt(2, stxxmskhk.getStdm().intValue());
psupdate.executeUpdate();