Mark Hansen wrote:
> I'm trying to understand the intended use of Unmarshal / Marshal
> callback events. For unmarshalling, what kind of bean property would I
> want to set on a value class either before or after unmarshal?
One use is to set parent pointers. The other is so that you can
implement custom ID/IDREF-like reference mechanism. I think I mentioned
this in one of my blogs.
> I'm even more confused about marshal callback events. The marshal
> callback interface doesn't provide access to the XML infoset that is
> being marshalled in to - only the parent of the JAXB value class and the
> Marshaller. What is the use case for setting properties of either the
> Marshaller and/or value class before or after marshalling it out to an
> infoset?
The initial motivation for me at least was only on the unmarshalling
side, but then many of us felt that not having anything for the
marshaller side would be somewhat inconsistent.
I think one potential use is to clean up / normalize the in-memory data
structure right before the marshalling.
I think you have a good point that it doesn't let you access the XML
infoset, but given that JAXB can marshal to so many different forms,
it's bit tricky to provide any XML infoset information to application.
--
Kohsuke Kawaguchi
Sun Microsystems kohsuke.kawaguchi_at_sun.com