Why we need "transient EntityManager"?

[hkjackjoke]

Hi,

Newbie & need help, after search the forum & web, I still don't know why need to put the keyword "transient" before EntityManager.
Can anyone please explain or show me the place to look for the answer, thanks?

    @PersistenceContext
    transient EntityManager Timer.entityManager;

Regards,

[Marten Deinum]

THe objects can get serialized in the httpsession (when used as formobjects for instance) and you really don't want to serialize your entitymanager... Hence the transient... It will be reinjected after deserialization of the objects.

[hkjackjoke]

Marten,

Thank you for the explanation.

[Andrew Swan]

The "transient" keyword also tells JPA to ignore this field when persisting the entity.

[hkjackjoke]

Andrew,

I see the reason now, thank you for the explanation.