JEP-238 & JEP-261 Coexistence

[Richard Opalka]

Comments below:

On 04/06/2016 12:34 PM, Alan Bateman wrote:
> On 06/04/2016 11:17, Richard Opalka wrote:
>> Hi Experts,
>>
>>    I expected if users provide 'multirelease' jar file with 
>> modules-info.class
>> placed in its META-INF/versions/9 folder would work without problems.
>> But I'm getting:
>>
>> Caused by: java.lang.IllegalArgumentException: META-INF.versions.9: 
>> Invalid package name:  Illegal character at index 4
>>
>> instead. Does it mean JEP-238 and JEP-261 cannot coexist?
> There isn't any support yet for modular JAR as multi-release JARs. 
> It's tracked as JDK-8146486 with the main question being whether the 
> compiled module declaration can be in the META-INF/versions tree or not.
>
> As things stand then a JAR file that does not have a module-info.class 
> in the top level directory is assumed to be an automatic module so 
> this is why it barps when trying to determine a package name from 
> META-INF/versions/9.
IMHO it should be allowed to put module-info.class to META-INF/versions
subtree as modules may evolve (their imports/exports) with different JDK 
versions. // My 2c.
>
> BTW: Just looking at the contents of your JAR file then it looks like 
> this is the EE version of the Common Annotations. In that case you 
> shouldn't need a multi-release JAR. Instead you should be able to put 
> the module-info.class in the top level directory and deploy it on the 
> upgrade module path.
Yes I know. Our requirement is to support both JDK8 and JDK9 with the 
same jar.
Thus in my experiments I have javax classes compiled for JDK8 and 
module-info.class for JDK9.
Multi-Release jar was my first attempt, when it failed I did what you 
propose above Alan.
>
> -Alan
Rio