[hibernate-dev] hiberate-commons-annotations and locating annotations

[Emmanuel Bernard]

On Fri 2013-08-30  6:27, Steve Ebersole wrote:
> 
> On Fri 30 Aug 2013 06:05:37 AM CDT, Emmanuel Bernard wrote:
> >>
> >>
> >>2) The 'declaringClassName' passed in to SimpleValueBinder#setType
> >>is Sub. So maybe we can leverage that. But
> >>org.hibernate.cfg.annotations.PropertyBinder#makePropertyAndValue
> >>(the main caller of this method) has explicit handle for null-ness
> >>so that makes me nervous.
> >>
> >>Given the differing rules for resolving converter to use for basic
> >>types, collections and composites and the fact that these
> >>distinctions are already handled in the PropertyHolder hierarchy, I
> >>think it would be better to handle those distinctions there. Either
> >>adding a separate method to inject the converter to use (making sure
> >>it is called before setType, ugh) or changing the signature of
> >>setType to accept the converter to use.
> >>PropertyBinder#makePropertyAndValue would then use
> >>PropertyHolder#resolveAttributeConverter to pass what it needs to
> >>pass.
> >>
> >>WDYT?
> >
> >
> >Yes that makes sense to consolidate this logic in PropertyHolder. But I
> >have to admit I failed to find an elegant algorithm and data structure
> >to resolve the convert use cases you have described. All involved some
> >back reading of annotations etc :(
> 
> Depends what you mean "back-reading".  I planned on sifting through
> the annotations as "resolve" is called.
> 
> >
> >BTW is it possible to have the illegal case by mean of mixing XML and
> >annotation. ie you have the @Convert on the property and the disable
> >facility at the class level in XML. Does the same rule apply?
> >Because for sure the XML and the annotation are treated equally by
> >commons annotation.
> <quote>
> The convert subelement is additive to any Convert or Converts
> annotations on the entity. It
> overrides any Convert annotation for the same attribute name. If a
> convert subelement is present,
> and attributes or subelements of that convert subelement are not
> explicitly specified, their default
> values are applied
> </quote>
> 
> My reading of that on your use-case is that we really should apply
> the XML-defined converter.  But hiberate-commons-annotations simply
> does not give us the information needed to be able to do that
> properly.

You can do that, you would code the logic in JPAOverriddenAnnotationReader in ORM Core.
Check getAttributeOverrides / mergeAttributeOverrides as an example of
how to read Java annotation, the XML "annotations" and merge the two as
you please.