JEP 238: Multi-Version JAR Files

[Paul Sandoz]

On Feb 27, 2015, at 2:27 PM, Florian Weimer <fweimer at redhat.com> wrote:
> On 02/12/2015 09:52 PM, Paul Sandoz wrote:
>> Hi
>> 
>> In connection with the JEP there is also a design document to help the discussion:
>> 
>>  http://cr.openjdk.java.net/~psandoz/jdk9/MultiVersionJar-8u60-9-design.md
>> 
>> We are especially interesting in hearing feedback from library developers, tool/IDE developers, and anyone doing funky stuff with class loading and JAR files.
> 
> I'm wondering how you propose to build such JAR files.  Do you think
> library developers will maintain two separate branches, compile one with
> JDK 8, the other one with JDK 9, and then use some (not yet existing?)
> tool to merge the output into a single JAR?  Is such automated merging
> even possible if the bytecode was compiled with different javac versions?
> 

In the last section of the design document i was trying to anticipate a particular approach, a multiversion project, with examples for compiling and packaging.

That is out of scope of the MVJAR effort itself but still very important and is dependent on getting buy in from tooling such as maven and gradle.


> What about presenting Javadoc in a useful fashion?

A MVJAR should only have one API.

Paul.