Cmp exclusive locking

Question

hi, is it possible to implement exclusive locking in cmp 2.0 ?
just like FOR ... UPDATE statement in oracle ?
help please

Answer 1

After having discussion with Mitesh, here is what we think
There are 2 ways to handle this issue
Approach 1:
Using UserTransaction in the servlet
ut = (UserTransaction) ic.lookup(
"java:comp/UserTransaction");
ut.begin();
findAll();
doProcessing();
ut.commit or rollback();
In this case all rows will be locked till we do commit or rollback
Approach 2:
Using BMT/CMT (Bean Managed Transaction/ContainerManagedTransaction) for session bean as a middle layer between servlet and CMP
For CMT in session beans
Now session bean will have a business method(having Required transaction attribute in CMT) doing
busineessmethod() {
findAll()
doProcessing()
BMT in session bean is similar to UserTransaction explained in servlet, only difference in getting usertransaction
For BMT , we need to do
context.getUserTransaction();
Please refer to samples/transaction samples for details