javafx_sbt_minimal

This is a minimal example of a bug I ran into while trying to build a working GraalVM native image of a Scala app with JavaFX, sbt, and the org.scalameta.sbt-native-image plugin, plus a bit of additional code to make it easy to compare it with what happens when we build a native image with the same JavaFX, but with Maven, and the com.gluonhq.gluonfx-maven-plugin plugin.

Setup

• OS: Linux Mint 20.1
• Arch: x86_64
• JDK: GraalVM CE 21.3.0, openjdk version 11.0.13 (JavaFX does not work yet with Java 17)
• Scala: 2.13.7
• SBT: 1.5.5
• JavaFX: 16 (JavaFX 17 does not work yet with SBT because of this issue)
• sbt-native-image: 0.3.1

Common ground

If you type sbt run from the console, it should download JavaFX dependencies, compile the app, and run it. A small window will open with a text "Hello from Scala!" in it.

If you want to do the same with Maven, make the changes described in comments in minimalexample.Main.scala and then run mvn javafx:run. The reason for the changes is that SBT and Maven look for the main class in a bit different way. SBT gets confused if the class extending the JavaFX Application class has the same name as the object which extends Scala App, but Maven used with scala-maven-plugin actually expects that. Something to do with Java 9 modules. Don't ask.

Native image

Run sbt nativeImage and sbt nativeImageRun. The native image will be compiled (this part works) and then it will crash at initialization with java.lang.NoClassDefFoundError: Ljava/nio/ByteBuffer:

sbt:javafx_sbt_minimal> nativeImageRun
Nov 13, 2021 5:16:01 PM com.sun.javafx.application.PlatformImpl startup
WARNING: Unsupported JavaFX configuration: classes were loaded from 'unnamed module @574a89e2'
Exception in thread "main" java.lang.RuntimeException: java.lang.NoClassDefFoundError: Ljava/nio/ByteBuffer;
  | => nat com.sun.javafx.tk.quantum.QuantumToolkit.startup(QuantumToolkit.java:290)
        at com.sun.javafx.application.PlatformImpl.startup(PlatformImpl.java:288)
	at com.sun.javafx.application.PlatformImpl.startup(PlatformImpl.java:160)
	at com.sun.javafx.application.LauncherImpl.startToolkit(LauncherImpl.java:658)
	at com.sun.javafx.application.LauncherImpl.launchApplication1(LauncherImpl.java:678)
	at com.sun.javafx.application.LauncherImpl.lambda$launchApplication$2(LauncherImpl.java:195)
	at java.lang.Thread.run(Thread.java:829)
	at com.oracle.svm.core.thread.JavaThreads.threadStartRoutine(JavaThreads.java:596)
	at com.oracle.svm.core.posix.thread.PosixJavaThreads.pthreadStartRoutine(PosixJavaThreads.java:192)
Caused by: java.lang.NoClassDefFoundError: Ljava/nio/ByteBuffer;
	at com.oracle.svm.jni.functions.JNIFunctions.FindClass(JNIFunctions.java:346)
	at com.oracle.svm.jni.JNIOnLoadFunctionPointer.invoke(JNILibraryInitializer.java)
	at com.oracle.svm.jni.JNILibraryInitializer.callOnLoadFunction(JNILibraryInitializer.java:72)
	at com.oracle.svm.jni.JNILibraryInitializer.initialize(JNILibraryInitializer.java:129)
	at com.oracle.svm.core.jdk.NativeLibrarySupport.addLibrary(NativeLibrarySupport.java:186)
	at com.oracle.svm.core.jdk.NativeLibrarySupport.loadLibrary0(NativeLibrarySupport.java:142)
	at com.oracle.svm.core.jdk.NativeLibrarySupport.loadLibraryAbsolute(NativeLibrarySupport.java:101)
	at java.lang.ClassLoader.loadLibrary(ClassLoader.java:131)
	at java.lang.Runtime.load0(Runtime.java:768)
	at java.lang.System.load(System.java:1835)
	at com.sun.glass.utils.NativeLibLoader.installLibraryFromResource(NativeLibLoader.java:214)
	at com.sun.glass.utils.NativeLibLoader.loadLibraryFromResource(NativeLibLoader.java:194)
	at com.sun.glass.utils.NativeLibLoader.loadLibraryInternal(NativeLibLoader.java:135)
	at com.sun.glass.utils.NativeLibLoader.loadLibrary(NativeLibLoader.java:53)
	at com.sun.glass.ui.gtk.GtkApplication.lambda$new$6(GtkApplication.java:187)
	at java.security.AccessController.doPrivileged(AccessController.java:87)
	at com.sun.glass.ui.gtk.GtkApplication.<init>(GtkApplication.java:171)
	at com.sun.glass.ui.gtk.GtkPlatformFactory.createApplication(GtkPlatformFactory.java:41)
	at com.sun.glass.ui.Application.run(Application.java:144)
	at com.sun.javafx.tk.quantum.QuantumToolkit.startup(QuantumToolkit.java:280)
	... 8 more

Please note that java.nio.ByteBuffer is already present in src/main/resources/jni-config.json and reflect-config.json. I tried to modify those files, as well as predefined-classes-config.json a bit to put the whole ByteBuffer class there, not just some of its methods, but to no avail. The error is exactly the same.

The JSON files in src/main/resources were generated with nativeImageRunAgent and copied from target/native-image-configs.

I know problems this kind of problems with ByteBuffer occur sometimes because of a difference between Java version used for compilation and for running the app but I don't know how it can apply here - both compilation and execution are on Java 11, and besides all works well with the standard JDK app, only the native image fails.

Maven version for comparison

Clean the project, make changes in the Main class, and then run mvn gluonfx:build gluonfx:nativerun. The app works. Also you can check that the executable file is much bigger (but that doesn't really need to mean anything).