request.getSession().getAttribute miss a row of data in tabel

[hon123456]

Deal all,

I have input three rows of data in a html table. But I found
the last row will disappear and lost when it return the data to
backend. I think that maybe caused there is an error checking which
prompts an error and after that , I change the value of the last(3rd)
row and try to save it. The last row disappear in the UI and being not
sent to the back end. Here is my code of the JSP

RosterCodeSetupCommand rosterCodeSetupCommand =
(RosterCodeSetupCommand)request.getSession().getAttribute("rosterCodeSetupCommand");
int cmd = rosterCodeSetupCommand.getCmd();
int pageNo = rosterCodeSetupCommand.getPageNo();
EtWorkTime etWorkTime = rosterCodeSetupCommand.getEtWorkTime();
List policyList = rosterCodeSetupCommand.getPolicyList();

As you can see, the EtWorkTime is get from the rosterCodeSetupCommand.
Usually, the rosterCodeSetupCommand will have all the rows in the
table. But now in EtWorkTime, I found last row data is lost.
And in the UI, when I press Save, the last row is disappear. So I
guess the problem is happened in
request.getSession().getAttribute("rosterCodeSetupCommand"); But I
can't figure out what can make the last row lost in this sentence.
Would you mind to give me some hints on what will make this happen and
I will try to trace the code by myself. Thanks.