bundling native libs in jars or modules

[Tom Schindl]

Did you check how SWT does addresses the problem? If you run it outside of OSGi it needs to deal with this problem as well.

Tom

Von meinem iPhone gesendet

> Am 17.05.2018 um 21:25 schrieb Johan Vos <johan.vos at gluonhq.com>:
> 
> Note: This is different from what is discussed in
> http://mail.openjdk.java.net/pipermail/openjfx-dev/2018-April/021762.html
> 
> The following text is about bundling native code within a jar, and doesn't
> talk about how to deal with platform-specific libraries in generic jar
> files.
> 
> At this moment, the standalone SDK for JavaFX 11-ea works fine, and javafx
> apps can be executed since the javafx jars will load the required native
> code from the libs that are part of the SDK.
> 
> When we want to download the javafx modules as modules (or jars with
> module-info), we don't have a local SDK with native libraries. The native
> libraries need to come with the downloaded jar. There are a number of
> options to do this, and a number of ongoing discussions (e.g. see
> http://mail.openjdk.java.net/pipermail/panama-dev/2018-April/001541.html).
> In summary, jmods already have support for native code but they are not
> scoped at runtime, and jars don't have a standard way for supporting native
> code.
> 
> I hope there will be a long-term solution for this in the VM in the future,
> but clearly we can't rely on this for the 11 release.
> Hence, we need to provide some JavaFX-specific fixes.
> Just to try the mechanism, I created a quick (and dirty) workaround in the
> NativeLibLoader. I committed it to a nativelibs branch of my openjfx fork:
> https://github.com/johanvos/openjdk-jfx/commit/f2c4c57a6197634e9c3bc1298ea14700057155a3
> 
> The good thing is that all JavaFX native lib loading is already delegated
> to the NativeLibLoader, so I only had to patch one file.
> 
> I modified the generated javafx.graphics.jar to include all libs that are
> generated (something that can be automated in a gradle task), and could
> successfully run javafx apps using
> java -p /path/to/my/jars --add-modules javafx.controls
> without specifying java.library.path or native libs or so.
> 
> This works for jars that I put myself on the classpath, hence it should
> also work for jars downloaded from maven central etc.
> 
> In case there will be a standard for bundling native libs with jar files in
> a future JVM, we can remove this hack. But even in the meantime, there are
> better solutions.
> One of the best options I think we should consider is using JavaCPP (
> https://github.com/bytedeco/javacpp)  . The main author of JavaCPP, Samuel
> Audet (in cc) describes here (
> https://github.com/tensorflow/tensorflow/issues/18397#issuecomment-381371636)
> why my hack will fail on Windows.
> 
> Another advantage of JavaCPP is that it is proven to work on ios and
> Android as well. Actually, that would allow us to get rid of the
> ios-specific code that is currently in NativeLibLoader.java.
> 
> Again, this is only tackling the issue of bunding native code with jars and
> not dealing with platform-specific resolution (although JavaCPP can help
> there as well).
> 
> - Johan