Private APIs not usable in Java 9?

Robert Krüger krueger at
Wed Apr 8 17:15:24 UTC 2015

OK, if that statement holds true it is not too unlikely it will be the
death of our plans to migrate to JFX (which I am trying to convince my
partners of). I am aware that using private APIs is a last resort and we
don't do that if we don't have to. Realistically the pace at which JFX
(which we think is a great technology btw.) matures, it is currently the
only way to handle the risk of running into something that does not work
(yet), which has happened to me many times just beginning to dive into
migration. Simply stating "it's not a good idea to do this" and hoping it's
going to work is ignoring the facts and I will probably not bet my business
on JFX without everything we lose, if enforcement of this is mandatory in
Java 9. Just looking at a few things in Jira, it is obvious that you are
already scheduling rather serious problems to Java 9 and I am not expecting
this to change very soon, because Oracle suddenly doubles the dev resources
for JFX. Taking away this (admittedly very ugly) way for developers to help
themselves at their own risk (in many cases until something is
fixed/implemented in the JDK by Oracle, which, of course, takes more time
than a hack) is IMHO not a good idea in the current phase of JFX. You will
probably lose yet more originally very interested software vendors who will
disappointedly move to native technologies because they simply cannot
deliver the product they want/have to, although they'd rather use Java
(FX). But, of course, it's your decision and legitimate to do it either
way. I'm just trying to show you a side here (that I think a number of
other ISVs here on the list know), that might need a little lobbying.

On the other hand, I would guess that deactivating the enforcement of this
in OpenJDK will probably not be too difficult anyway, so if you decide not
to offer to make this configurable one could find a way by building a
modified OpenJDK and shipping that but it would be nicer if Oracle would
acknowledge that this helps some people at this stage and offer it. After
all some of those people are JFX lobbyists out there and there are not many
at the moment compared to the competing technologies.

It all may be a different situation a few years from now when JFX has
matured and seen a few thousand serious commercial applications built on
top of it.

On Wed, Apr 8, 2015 at 6:25 PM, Joe McGlynn <joe.mcglynn at> wrote:

> This is unrelated to FX, no Java applications will be able to use private
> APIs in JDK 9.  There _may_ be a temporary compatibility mode, but clearly
> use of them is not something you should plan on regardless of UI technology.

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