By the way, how can I let JPA return a deatached object ?
I make use of GenericDaoJpa.java which is attached to this message.
http://www.nabble.com/file/p24571326/GenericDaoJpa.java GenericDaoJpa.java
Greg Lindholm-2 wrote:
>
>> I use JPA (hibernate) to persist.
>>
>>
>>
>> An example of action that use prepare to load a person object from
>> transactional manager. When the validate fails and it return back to the
>> input page the request ends and the transaction persists the dirty user
>> object to database. The dirty user object should not be persisted if the
>> validation fails.:
>>
>> public class PersonAction extends BaseAction implements Preparable {
>>
>> private PersonManager personManager;
>> private Person person;
>>
>> public void prepare() {
>> person = personManager.getPerson(id);
>> }
>>
>> public String savePerson() {
>> manager.savePerson(person);
>> return SUCCESS;
>> }
>>
>> public void validate() {
>> if (person.firstName.length < 5 and person.firstName > 10) {
>> addActionError("Firstname length should be between 5 and 10
>> characters.");
>> }
>> }
>>
>> }
>>
>>
> This isn't really a Struts problem, it just the way Hibernate works.
>
> If you make changes to a monitored object (Persistent state) from the
> database then Hibernate will detect this and save the changes to the
> database when you commit the transaction. There is actually no need to
> call
> "save" to update a db object it will happen automatically.
>
> To "fix" your problem you have a couple of choices:
>
> 1) Don't make changes to db objects unless you are sure you want them
> saved. This would mean changing your actions to work with copies of the
> objects or Detached objects instead of the actually db objects (this is
> what
> I do).
>
> 2) Don't commit the transaction if the validation fails. Do a rollback
> instead.
>
>
--
View this message in context:
http://www.nabble.com/Prevent-persisting-data-when-validation-fails-tp24566713p24571326.html
Sent from the Struts - User mailing list archive at Nabble.com.
---------------------------------------------------------------------
To unsubscribe, e-mail: [email protected]
For additional commands, e-mail: [email protected]
