optimistic-locking

I use Spring 2.5 and Hibernate JPA implementation with Java and "container" managed Transactions. I have a "after user commit" method that updates data in background and need to be committed regardless of ConcurrencyFailureException or StaleObjectStateException exception, because it will never be shown to client. In other words, need to make Optimistic Lock to Pessimistic. (Could happen if methods execution will take little bit longer and someone changed data in other transaction) I read a a lot about idempotent stuff, retry if exception in search for DEFAULT_MAX_RETRIES or 6.2.7. Example or

I have spent my morning reading all the top articles that Google churns up on optimistic locking , and for the life of me, I still don't really get it. I understand that optimistic locking involves the addition of a column for tracking the record's "version", and that this column can be a timestamp, a counter, or any other version-tracking construct. But I'm still not understanding how that ensures WRITE integrity (meaning that if multiple process are updating the same entity at the same time, that afterwards, the entity correctly reflects the true state it should be in). Can someone provide a

I am trying to implement Optimistic locking in-order to avoid lost update situation. In my application when two user fetch same record and the first user updates it with some changes. This change is not visible to the second user who view the same record and he makes some changes by himself and updates it. Due to which the first persons change is lost. In-order to prevent this I have written the following but still the issue persist. I am new to this concept, not able to identify the issue. I have tried to achieve this by reading doc 11.3.4. Customizing automatic versioning section. The

The EJB method (using CMT) that updates an entity supplied : @Override @SuppressWarnings("unchecked") public boolean update(Entity entity) throws OptimisticLockException { // Code to merge the entity. return true; } This will throw the javax.persistence.OptimisticLockException , if concurrent update is detected which is to be handled precisely by the caller (a managed bean). public void onRowEdit(RowEditEvent event) { try { service.update((Entity) event.getObject()) } catch(OptimisticLockException e) { // Add a user-friendly faces message. } } But doing so makes an additional dependency from