Hi,
How about using bean-managed transaction in a stateful session bean?
(check up chapter 11 in EJB1.1 specs).
- JT -
On Thursday, April 5, 2001, at 11:37 PM, Keith Kwiatek wrote:
> I think you mean "any time you want to work pessimistically" ....
>
> This is an outstanding issue.... I have also been wrestling with the
> same
> thing for a while now.... and it seems, for now, that the kludgy
> timestamp
> method is about the only solution.... I saw some more discussion on this
> issue on www.theserverside.com about this very issue, but I forget
> exactly
> where on the web site....
>
> EJB doesn't address "pessimistic" row level locking in a stateless
> environment --BUT IT SHOULD! EJB must address this issue at some
> point... it
> is such a basic requirment! The whole idea of the J2EE is to provide a
> framework of basic utilities shared by applications.
>
> Keith
>
> ----- Original Message -----
> From: "Jonathan Goldberg" <[EMAIL PROTECTED]>
> To: <[EMAIL PROTECTED]>
> Sent: Wednesday, April 04, 2001 11:07 PM
> Subject: Re: Record-locking in J2EE/JSP/Servlet apps?
>
>
>> Hi Bill
>>
>> I don't know that this problem is specific to JSP, and
>> I don't know if EJB solves the problem automatically.
>>
>> Basically, any time you want to work optimistically, you
>> will need to verify that the data you are trying to update
>> is the data you retrieved. One manual strategy is to add
>> a timestamp to the table(s), and do something like:
>>
>> {
>> retrieve data without transaction
>> display data to user
>> }
>>
>> later on
>> {
>> get data sent by user
>> open transaction
>> retrieve data from database
>> compare timestamps
>> if same then
>> {
>> update data with user database
>> update timestamps
>> commit transaction
>> send OK confirmation to user
>> }
>> else
>> {
>> rollback transaction
>> send new data and error message to user
>> }
>> }
>>
>> Hope this helps
>>
>> Jonathan
>>
>> ==========================================
>> Jonathan Goldberg 8, HaP'nina Street
>> Amdocs (Israel) Ra'anana, 43000, Israel
>> +972-9-7762071 (work) +972-9-7763800 (fax)
>> mailto:[EMAIL PROTECTED]
>>
>>
>> -----Original Message-----
>> From: Hines, Bill [mailto:[EMAIL PROTECTED]]
>> Sent: Wednesday, April 04, 2001 9:44 PM
>> To: [EMAIL PROTECTED]
>> Subject: Record-locking in J2EE/JSP/Servlet apps?
>>
>>
>> How are any of you solving the problem in the stateless webapp context
> where
>> two users pull up the same record from a database in a JSP page, and
>> user
>> one changes the address and saves but then user two, who has the old
> address
>> on his JSP page, changes the phone number and hence over-writes user
>> one's
>> address change? Are you locking the record in the back-end database and
> then
>> implementing the SessionBindingListener to release it when the session
>> expires, if the user leaves the webapp without logging out? Does EJB
>> solve
>> this problem? I'd like to hear the solutions that are out there.
>>
>>
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> http://www.jguru.com/jguru/faq/faqpage.jsp?name=JSP
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