Thanks.
Config management ("Process") hasn't helped, the project is too large with
too many players.
This was easy with CORBA, the IDL had a version stamp that was checked. It
surprises me this isn't more of an issue for JAXB users.
Thanks again.
On Sat, Sep 1, 2012 at 12:24 PM, Wolfgang Laun <wolfgang.laun_at_gmail.com>wrote:
> I'd say that this is more a Configuration Management problem in a
> distributed development environment than a JAXB problem. (You'd have it
> with any kind of protocol while contents and/or representation aren't
> stable or taken from the same SW baseline.)
>
> Trying to put the baseline identifier in the data isn't going to help
> unless you make sure that unmarshalling a mismatched version of the data
> succeeds - at least to the degree you can access the version id.
>
> Now if you have to reckon with differing sets of Java classes with
> annotations, you might consider generating XML schemata from them and
> validate your XML data against the schema. (This is simple and supported by
> JAXB.)
> This may exhibit more problems than just versioning problems.
>
> If XML documents are messages, agreement about the protocol versions
> should be reached in a simple
> message exchanged after connection is established.
>
> This is not along the lines you have proposed - maybe another view helps
> ;-)
>
> -W
>
>
> On 1 September 2012 17:58, Mike Summers <msummers57_at_gmail.com> wrote:
>
>> We're building a many developer app using JAXB and keep stumbling on
>> problems that all come back to "version" mismatch between producers and
>> consumers of JAXB objects.
>>
>> Process hasn't alleviated the pain so I was thinking about something
>> along the lines of CORBA object versioning for JAXB, maybe via a required
>> final field whose values must match. Something like a Serializable
>> serialVersionUID that is added to the marshal stream when the object is
>> marshaled and is required and whose value is *checked* when the object
>> is unmarshaled.
>>
>> Various check rules can be implemented, but in this case I only want
>> equality. If the current version of a Foo is 1.1 and I get data to
>> unmarshal whose version is anything other than 1.1 I will reject it.
>>
>> As an added bonus I'd like to inject the version value as the Maven
>> version # :-)
>>
>> This is all using annotations, no xsd.
>>
>> Any suggestions as to a rational approach?
>>
>> Thanks.
>>
>
>