Exporting - the wrong default?

[Alex Buckley]

On 7/29/2016 4:24 AM, Andrew Dinn wrote:
> On 28/07/16 23:05, Alex Buckley wrote:
>> Down-thread, Alan asked for examples of the changes you've made to a 3rd
>> party's descriptor, but I think you're raising "descriptor baked into a
>> 3rd party jar" as a concern for modules delivered in the future rather
>> than for JAR files you have on hand today. I think this because Sanne
>> Grinovero spoke on 7/12 of CREATING descriptors from scratch:
>>
>> "In fact in my team we also have experience "packaging" lots of these
>> OSS Java libraries into JBoss Modules, and have always appreciated that
>> - as an assembler - with JBoss Modules I can define the dependencies via
>> external metadata, without having to recompile or have to reassemble the
>> jar. As you [meaning John Rose] suggest, it is indeed useful to be able
>> to override the intent of the library authors, especially as different
>> libraries are developed by independent teams / communities / companies."
>>
>> I assume the "intent of the library authors" is found in the POM, and he
>> translate it to module.xml [1] with occasional tweaks to add, remove,
>> and optionalize dependencies.
>>
>> Am I on track?
>
> Yes, you are on track. The problem I was referring to relates to the
> future possibility of having to integrate Jigsaw-enabled components into
> middleware tools like containers, specifically to whatever management
> problems this may cause. The potential for complexity is twofold. A
> container like EAP may be faced with having some of the component jars
> it relies on being Jigsaw-modularized. It may also need to deploy
> Jigsaw-modularized application jars which need to access the
> functionality it manages. In both cases the specific problem I was
> concerned with was the need to add, remove or optimize dependencies that
> Sanne refers to.

Mark already discussed with Jason how a container can rewrite 
descriptors as modules are being spun up [1] so I'm struggling to see 
the problem unless there is some burning desire to rewrite the 
descriptor by hand prior to run time. I can understand that if Sanne 
takes third party JARs containing no descriptors, and manually creates 
descriptors by spying on the POMs, then sure it's nice to keep the 
descriptors external and the JARs unchanged ... but a Jigsaw modular JAR 
already contains a descriptor that we assume is authoritative unless a 
container is rewriting at run time.

Alex

[1] http://mail.openjdk.java.net/pipermail/jigsaw-dev/2016-July/008637.html