Private APIs not usable in Java 9?

Jonathan Giles jonathan.giles at
Thu Apr 9 07:53:58 UTC 2015

For what it is worth, investigations are underway in relation to UI 
control skins and behaviors. It's too early for anything definitive to 
announce, but it is not inconceivable that may become, 
more or less (with a lot of work cleaning up, etc).

In terms of behaviors, some investigations are already underway in 
RT-21598, but these too are only early, and fall under the bigger 
project of getting UI controls and CSS APIs into a jigsaw-friendly form 
for JDK 9 (which is a huge undertaking, and community support will be 
useful and sought at the appropriate time).


-- Jonathan

On 9/04/2015 5:39 p.m., Tom Schindl wrote:
> Hi,
> in SWT on JavaFX (most likely NOT a common useage of JavaFX):
> -------------------------------------------------------------
> I had to reside to private-API when it comes to:
> * text calculations where there is no public API for things like
>    FontMetrics, TextLayout, ...
> * For some of the direct drawing code I had to use com.sun.javafx.geom.*
> * For some operations I had to access the &
> * I had to get access to the VirtualFlow
> To implement custom controls e.g. CodeEditor:
> ---------------------------------------------
> *
> * com.sun.javafx.scene.control.behavior.KeyBinding
> * com.sun.javafx.css.converters.InsetsConverter
> * com.sun.javafx.css.converters.PaintConverter
> * com.sun.javafx.scene.text.HitInfo
> So to summerize the most lacking API is in the font/text rendering space
> and to get public access to VirtualFlow would be a nice to have!
> Tom
> On 08.04.15 18:44, Phil Race wrote:
>>>   it's not strictly JFX-only.
>> Its not remotely FX only, in fact I could argue FX is not so affected,
>> as being relatively new it does not have 20 years of accumulation
>> of people using internal APIs that the larger JDK does, often dating from
>> when there were no suitable public APIs. There still remains some
>> of that with sun.misc.Unsafe as pointed out which will indeed be
>> inaccessible in modular mode. But the FX list isn't really the place
>> for that discussion. The jigsaw-dev is the appropriate list. FX
>> is simply bound by the rules that are set there.
>> There will be a -XX flag in JDK 9 that jigsaw provides to aid in the
>> transition.
>> Also remember FX is open source. You can propose patches !
>> If there are specific APIs that are missing from FX that are suitable
>> to be *supported* public APIs then those could be considered here (this
>> list).
>> -phil.
>> On 4/8/2015 9:28 AM, Mike Hearn wrote:
>>> sed -i 's/private/public/g' ;)
>>> The whole notion of a strongly enforced private keyword is IMHO dumb when
>>> not using sandboxing. The number of gross hacks that occur in an
>>> attempt to
>>> work around overly strict enforcement of this stuff is crazy. The D
>>> compiler has a special flag that disables visibility enforcement when
>>> compiling unit tests, and that's a good idea, but why not go all the way
>>> and just make accessing of private state a compiler warning a la
>>> deprecated?
>>> I also need to use private JFX APIs. I think any real JFX app does,
>>> way too
>>> much basic stuff relies on it. Heck, the number of popular Java libraries
>>> that depend on sun.misc.Unsafe is huge. If Java 9 stabs us in the back in
>>> this regard then I will just write a simple tool that flips
>>> private->public
>>> either at the source level or via bytecode editing, and see what
>>> happens :-)
>>> On Wed, Apr 8, 2015 at 6:14 PM, Robert Krüger <krueger at>
>>> wrote:
>>>> Hi,
>>>> I hope this is not too off-topic, because although it came up in a JFX
>>>> context it's not strictly JFX-only.
>>>> Someone from our team recently had a chat with a high-ranking regional
>>>> Oracle representative who gave a talk on the state of JFX. Our guy
>>>> explained our situation (evaluating JFX to migrate our swing-based
>>>> product,
>>>> feeling it's in principle the right technology but still having
>>>> show-stopping limitations like RT-36215) and the Oracle guy offered to
>>>> relay our concrete questions to the right people, which he did.
>>>> The answer we got contained one thing that really was a bit of a
>>>> shock and
>>>> I would like someone to either confirm this or clear up a
>>>> misunderstanding.
>>>> The statement was that private APIs will not be available in JDK 9
>>>> due to
>>>> modularity restrictions. If that is the case and we no longer have the
>>>> ability to build temporary workarounds using private APIs (which in our
>>>> case is controllable as we ship the JRE with our product), I would
>>>> probably
>>>> have to stop any development going into the direction of JFX as we will
>>>> probably have to use 9 at some point because many things now
>>>> scheduled for
>>>> 9 will not get fixed in 8 and we will most likely still need workarounds
>>>> using private API, at least that's what my current experience with JFX
>>>> tells me.
>>>> Please tell me that this was a misunderstanding (maybe meant for the
>>>> general case where one does not ship the JRE) or a non-engineering
>>>> source
>>>> that simply made mistake.
>>>> Best regards and thanks in advance,
>>>> Robert

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