EntityHome and optimistic transaction

[azalea]

Hi,

Now I struggle with EntityHome :)

my environments:
JBoss AS 4.2.0.GA
Seam 2.0.0.BETA1(CVS)
Seam gen-generated project(ear)

I have a simple CRUD app using EntityHome.
The app needs the optimistic transaction.

Scenario:
1. In browser tab#1, display the person list.
2. In tab#1, select a person from the person list for editing.
(1)the selected person id is bound to EntityHome.setId().
(2)long-running conversation begins.
(3)the view for editing the person information is rendered.
3. In tab#2, display the person list.
4. In tab#2, select the same person from the person list for deleting.
(1)the selected person id is bound to EntityHome.setId().
(2)long-running conversation begins.
(3)the view for deleting is rendered.
5. In tab#2, click "delete" button.
(1)EntityHome.remove() is called.
(2)long-running conversation ends.
(3)now the person record doesn't exist in database table.

Now If I click "edit" button after editing any entity attributes in tab#1,
OptimisticLockException is thrown.
Because the person record was deleted by tab#2, this is OK.

But if I click "edit" button "without" editing any entity attributes in tab#1,
OptimisticLockException is not thrown.
And the following occur:
-Any update SQLs don't seem to be executed.
-However JSF message "successfully updated" added by EntityHome is displayed.

How can I detect this situation in my app?

Thanks in advance.

[hstang]

What does "edit" button do? does it call entityHome.update ? Maybe somewhere the dirty flag is not being set and you may to forcefully set that dirty flag to force update.

[azalea]

Hi, hstang.

Thanks for your reply.

What does "edit" button do? does it call entityHome.update ?

Yes, it does.

Maybe somewhere the dirty flag is not being set and you may to forcefully set that dirty flag to force update.

I tried setDirty(), but the situation didn't change.

@Name("personManager")
public class PersonManager extends EntityHome<Person> {

 ... ...

 @Begin(join=true)
 public void startUpdate() {
 setDirty(); // added
 }

 @End
 public void update() {
 setDirty(); // added
 super.update();
 }
}

I think I need to see the Seam source code in detail.
Your help is a welcome anytime :)

Thanks.

[hstang]

Hello,

I suspect it might not be related to Seam and maybe Hibernate, (if that's what you are using as your JPA provider). This is just my guess though.

[azalea]

Hi,

I think so, too.
maybe Hibernate's automatic dirty checking ...

Because I'm newbie in not oly Seam but also Hibernate,
I can't still find the solutions :(
I will search hibernate forum or/and buy Gavin's book :)

[pmuir]

You probably need to extend EntityHome with some custom logic to detect this sort of situation.

[azalea]

Hi, pete.

Thanks for your comment.

I'll try to write my dirty checking code.

[lisaanm]

Hi,
Under the same circumstance (original post), i achieved expected result by using Hibernate's @version annotation.
Here's link for Hib doc

http://www.hibernate.org/hib_docs/annotations/reference/en/html_single/#entity-mapping-entity-version

Hope this helps

[azalea]

Hi, lisaanm.

Thanks for your help.

I was also able to solve the problem by using @Version and EntityManager.lock() :)

Thanks a lot.