Persistent interfaces & custom value handler

[Matthew Adams <ma...@matthewadams.me>]

Hi all,

We make use of persistent interfaces in our object model.  All of our
entities have a Long id, including all implementations of all
persistent interfaces, so we'd like to map any field that refers to a
persistent interface to two columns, one for the id value and one for
the implementation class name.  Our custom value handler is working
nicely for single-valued fields, but it is not treating collection of
an interface correctly.  Instead of OpenJPA iterating the collection
and calling our custom value handler, it is passing the collection
itself to our value handler.

Question:  how do configure OpenJPA that whenever it encounters an
object of a given type, whether it be in a single- or multi-valued
field, to use a specific value handler?

If we can't do that, how do we implement a value handler that handles
collection fields of types that need to have custom value handlers?

Thanks,
Matthew

Re: Persistent interfaces & custom value handler

[Matthew Adams <ma...@matthewadams.me>]

Perhaps this is a more direct way of asking the question:

How do we tell OpenJPA that whenever it encounters a single- or
multi-valued field of one of our persistent interface types, use our
value handler?

We currently use the @Strategy annotation on single-valued fields,
which is ok, but (1) it doesn't work on multi-valued fields, and (2)
we'd like to specify it across all entities without having to go to
place the annotation on each field individually.

On Wed, Oct 21, 2009 at 9:12 AM, Matthew Adams <ma...@matthewadams.me> wrote:
> Hi all,
>
> We make use of persistent interfaces in our object model.  All of our
> entities have a Long id, including all implementations of all
> persistent interfaces, so we'd like to map any field that refers to a
> persistent interface to two columns, one for the id value and one for
> the implementation class name.  Our custom value handler is working
> nicely for single-valued fields, but it is not treating collection of
> an interface correctly.  Instead of OpenJPA iterating the collection
> and calling our custom value handler, it is passing the collection
> itself to our value handler.
>
> Question:  how do configure OpenJPA that whenever it encounters an
> object of a given type, whether it be in a single- or multi-valued
> field, to use a specific value handler?
>
> If we can't do that, how do we implement a value handler that handles
> collection fields of types that need to have custom value handlers?
>
> Thanks,
> Matthew
>



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