JAXP default implementation and JDK-8152063

[huizhe wang]

On 3/31/2016 8:48 AM, mark.reinhold at oracle.com wrote:
> 2016/3/29 0:21:05 -0700, alan.bateman at oracle.com:
>> On 28/03/2016 23:46, huizhe wang wrote:
>>> Thanks David.  So I understand the dynamic nature of the server
>>> configuration. There maybe two options to solve it:
>>>
>>> ...
>>>
>>> 2) Add a new type FinderDelegate for processes such as the "proxy" in
>>> your case to implement. If the FinderDelegate process fails to locate
>>> a provider, it would signal the jaxp process (by returning null) to
>>> fall back to the JDK-default implementation. In other words, when the
>>> system property points to a FinderDelegate, the 4-step JAXP process is
>>> reduced to two: delegate the process to the FinderDelegate, and fall
>>> back to the system default implementation.
>> The devil is in the detail of course. You haven't said if the
>> FinderDelegate implementation has to be visible via the system class loader.
>>
>> I think the main thing is to tread carefully and it would be very easy
>> to introduce a troublesome mis-feature here.
> Indeed.
>
> This has been an interesting discussion.  Now that I understand David's
> scenario better, I suspect this is just one instance of a more general
> problem, and in fact one that should be solved by a module-system
> requirement we previously recorded but have not yet addressed:
>
>    http://openjdk.java.net/projects/jigsaw/spec/reqs/#selective-binding
>
> Let's please not add yet more complexity to JAXP, if we can help it.

Ok. So it looks like we've presented an use case.

-Joe

>
> - Mark