Private APIs not usable in Java 9?

Donald Smith donald.smith at
Wed Apr 8 19:15:42 UTC 2015

Making any theoretical flag available to the deployment side would 
entirely miss the point.

Let me be blunt -- sun.misc.Unsafe must die in a fire.  It is -- wait 
for it -- Unsafe.  It must go.  Ignore any kind of theoretical rope and 
start the path to righteousness _*/now/*_. It is still years until the 
end of public updates to JDK 8, so we have /*years */to work this out 
properly.  But sticking our heads in the collective sands and hoping for 
trivial work arounds to Unsafe is not going to work.  If you're using 
Unsafe, this is the year to explain where the API is broken and get it 

Please help us kill Unsafe, kill Unsafe dead, kill Unsafe right, and do 
so as quickly as possible to the ultimate benefit of everyone.

  - Don

On 08/04/2015 2:56 PM, Stefan Fuchs wrote:
> Hi,
> then I can only hope, that this flag is available to webstart 
> applications.
> Webstart applications have no control over the installed jre. In the 
> past we encountered various bugs in the jre, which required using 
> internal apis for workarounds.
> For example in some releases of Java 7 the swing gui thread did not 
> start unless hacking internal apis (see 
> for details). If such an 
> error occurs again in the future and we are no longer able to hack 
> around the problem, our only choice to keep our business alive, is to 
> discourage users from upgrading to newer versions of the jre, exposing 
> them to security risks.
> - Stefan
>> >  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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