Proposed implementation of JEP 182 in JDK 11: drop javac support for -source/-target/--release 6

[joe darcy]

On 5/10/2018 3:26 PM, Emmanuel Bourg wrote:
> Le 10/05/2018 à 19:56, joe.darcy at oracle.com (joe darcy) a écrit :
>
>> Given the age of JDK 6, I think it is reasonable in 2018 for JDK 11 to
>> drop support for -source/-target/--release 1.6/6, leaving support for 7,
>> 8, 9, 10, and 11. This provides support for four rather than three older
>> versions in JDK 11, but better matches the time span of releases
>> discussed in the JEP.
> The short lived releases don't really matter in this context, most
> developers just skip them and aim for the LTS releases. I think the JEP
> 182 policy should be translated to "one + 3 LTS back", so for Java 11
> that would mean supporting 6, 7, 8, (9, 10), and 11. With this logic the
> next Java 17 LTS would support 7, 8, (9, 10), 11, (12, 13, 14, 15, 16),
> and 17. I suggest dropping the oldest version in the release immediately
> following the newest LTS (so Java 6 support would be removed in JDK 12,
> and Java 7 support would go away in JDK 18).

Copying a comment I left this January in the bug database view of JEP 182:

> Note that with the six month release cadence 
> (http://mail.openjdk.java.net/pipermail/discuss/2017-September/004281.html) 
> being used starting with JDK 10, the chronical range covered by "one 
> plus three back" would be much shortened. In due course, this policy 
> will be updated accordingly, possibly taking into account LTS (long 
> term support) releases and possibly offering a sparse set of values. 
> For example, one possible policy would be to support the last two LTS 
> releases and each release after the most recent LTS, but not the 
> releases between those two LTS releases. 

https://bugs.openjdk.java.net/browse/JDK-8046172?focusedCommentId=14145783&page=com.atlassian.jira.plugin.system.issuetabpanels:comment-tabpanel#comment-14145783

In example, the LTS release of JDK 18 would support 18, 17, 16, 15, 14, 
13, 12, 11 (LTS), 8 (effectively a LTS) with 9 and 10 *not* being supported.

Cheers,

-Joe