Critical Issue - Locking Error - Stateless BC4J Application

Question

Hi,
We are using "Stateless" mode in our BC4J project. Our View form done with Datawebbeans, Edit Form and Submit Edit Form done with Datatags. We are using Jdeveloper 3.2.
In multi-user environment, we are noticing that if two users open the same record at the same time, for editing, it is allowing both the users to edit the same record. We expect the second user to get an error message something like "Row Has been Changed - Re-query to see the change". But its not the case.
This is a very critical issue for us and any help from JDEV team is appreciated.
Thank you in advance
Virinchi
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Answer 1

The following information from Jdeveloper 3.1 Help (User Guides - Developing Business Components - Understanding Transactions - About Application Modules and Transactions) might be useful:
Client applications connect to databases and manage transactions by using the oracle.jbo.Transaction interface. Some useful methods of the Transaction interface with regard to Application Modules are:
commit - Commit the transaction; saves all changes to the database. If the database connection is established, the transaction is implicitly started.
connect - Attempt to establish a connection to the given database URL.
disconnect - Disconnect the server from the database.
**getLockingMode** - Get the preferred locking mode for this transaction. Currently the locking mode defaults to LOCK_PESSIMISTIC.
rollback - Rollback the transaction; discard all changes.
setLockingMode - Set the preferred locking mode for this transaction. Changing the locking mode affects only subsequent locks that are placed
If you have an Application Module and DataSource defined with Data Tags like this:
<%@ taglib uri="/webapp/DataTags.tld" prefix="jbo" %>
<jbo:ApplicationModule configname="dbproject3.Dbproject3Module.Dbproject3ModuleLocal"
id="Dbproject3Module" username="db" password="project" />
<jbo:DataSource id="ds" appid="Dbproject3Module" viewobject="BlChangesView" >
</jbo:DataSource>
Then you can access the Application Module, using Java Code like this:
jsp:useBean class="oracle.jbo.html.databeans.RowsetNavigator" id="rsn" scope="page" >
<%
rsn.setReleaseApplicationResources(false);
rsn.initialize(pageContext,"JSPFrame_dbproject3_Dbproject3Module.BlChangesView");
oracle.jbo.Row row = rsn.getRowSet().last();
oracle.jbo.domain.Number num = ((oracle.jbo.domain.Number)row.getAttribute("ChangeCode"));
ccode = num.intValue();
out.println("<h2>Change Code, by webbean is: " + ccode);
%>
</jsp:useBean>
Use:
ApplicationModule am =rsn.getRowSet().getApplicationModule()
then get the transacton with
am.getTransaction()
Hope this helps.
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