JEP 238: Multi-Version JAR Files

[Alan Bateman]

On 27/02/2015 13:27, Florian Weimer wrote:
> :
> 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?

This submitted JEP is good reading and gives an idea how how to compile 
to older JDKs:
   http://openjdk.java.net/jeps/8058150

-Alan.