Hi Craig,
Thanks for writing this up. I have a question though: why do you have this
(strong - "must not") requirement no to use entity serialization for EM
serialization?
thanks,
-marina
Craig L Russell wrote:
> Hi,
>
> Here is a straw proposal for specifying the contract between the
> container and the EM for passivation:
>
> The EM must be Serializable [Core contracts 4.2], and the container
> invokes the EM writeObject (ObjectOutputStream) during passivation. The
> EM writes the current persistence context to the output stream,
> including the current state of managed fields and properties of managed
> Entities.
>
> During activation (either in the same VM or in a different VM) the EM is
> read via readObject (java.io.ObjectInputStream). The stream has the
> contents that were written during writeObject.
>
> The EM is responsible for restoring the state of the persistence context
> as of the time of passivation. Specifically, the restored persistence
> context contains exactly each Entity that was managed by the saved
> persistence context. The state of each persistent property or field in
> each Entity is restored to the persistence context.
>
> The EM relies on the container to properly serialize and deserialize
> references to UserTransaction, TransactionSynchronizationRegistry, and
> ResourceFactories (specifically including JDBC DataSource).
>
> The EM must not use the user-defined serialization behavior of Entity
> classes, as this behavior is in the domain of the POJO and is not part
> of the persistence infrastructure. Specifically, writeObject,
> writeExternal, writeReplace, readObject, readExternal, readResolve
> methods of Entity classes must not be invoked by the EM during the process.
>
>
> The restriction in the specification "4.2 A container must not passivate
> a stateful session bean with an extended persistence context unless
> the following conditions are met:[9] • All the entities in the
> persistence context are serializable. " is ignored.
>
>
> Craig
>
> Craig Russell
>
> Architect, Sun Java Enterprise System http://java.sun.com/products/jdo
>
> 408 276-5638 mailto:Craig.Russell_at_sun.com
>
> P.S. A good JDO? O, Gasp!
>
>