Java Certification and downport of features to older releases

[Volker Simonis]

Hi,

I want to ask for you opinion regarding the following scenario:

1. A vendor X decides to provide LTS support for a specific Java release N
2. 6 month later, the new N+1 short term-release of Java introduces a
nice new language feature F (let's say something like local variable
type inference).
3. Vendor X doesn't want to support release N+1 because it is only a
short term release. But feature F is quite appealing and there's a
high demand for it, so he decides to downport it to his Java release
N. The new feature F is protected by a command line switch.

Questions:

a. Can vendor X certify his new N release as being Java N compatible?

I would say yes, because even if feature F wouldn't be protected by a
command line switch, the TCK for version N can not contain any tests
which check the absence of support for feature F.

b. Can vendor X claim that his JDK is Java N compatible but
additionally supports feature F from Java N+1?

So this is the more interesting question for which I don't know the
answer. Even if he wouldn't be allowed to claim it, as a matter of
fact he could still support it and his clients could use it.


I think with the previous release model, we didn't had such kind of
problems because of the long time frame between two releases. But with
the new, frequent release cadence and the fact that non-LTS releases
will be only supported for 6 months, the scenario sketched above could
be quite attractive.

On the one hand, such an approach could be beneficial for Java,
because it would give features which are introduced in non-LTS
releases a much broader adoption and visibility (few people will
probably use non-LTS releases in production). That's good to have,
before we bake such a feature into an LTS release.

On the other hand, it could lead to a certain amount of fragmentation,
if different implementations of Java N support different (if any)
additional features from Java N+1, N+2, etc.

What do you think?

Thank you and best regards,
Volker

PS: I know that the question of LTS vs. non-LTS releases is not
relevant for the EG. But the question of certification and claiming
compatibility is?