Problem using JavaFX Application class

[Sander Mak]

Hi,

When trying to run a module with a main class that extends javafx.application.Application, the following exception is thrown by the VM:

Exception in thread "main" java.lang.RuntimeException: Unable to construct Application instance: class javamodularity.easytext.gui.Main
	at com.sun.javafx.application.LauncherImpl.launchApplication1(javafx.graphics at 9-ea/LauncherImpl.java:926)
	at com.sun.javafx.application.LauncherImpl.lambda$launchApplication$140(javafx.graphics at 9-ea/LauncherImpl.java:220)
	at java.lang.Thread.run(java.base at 9-ea/Thread.java:804)
Caused by: java.lang.IllegalAccessException: class com.sun.javafx.application.LauncherImpl (in module javafx.graphics) cannot access class javamodularity.easytext.gui.Main (in module javamodularity.easytext.gui) because module javamodularity.easytext.gui does not export javamodularity.easytext.gui to module javafx.graphics
	at sun.reflect.Reflection.throwIllegalAccessException(java.base at 9-ea/Reflection.java:465)
	at sun.reflect.Reflection.throwIllegalAccessException(java.base at 9-ea/Reflection.java:456)
	at sun.reflect.Reflection.ensureMemberAccess(java.base at 9-ea/Reflection.java:98)
	at java.lang.reflect.AccessibleObject.slowCheckMemberAccess(java.base at 9-ea/AccessibleObject.java:370)
	at java.lang.reflect.AccessibleObject.checkAccess(java.base at 9-ea/AccessibleObject.java:362)
	at java.lang.reflect.Constructor.newInstance(java.base at 9-ea/Constructor.java:435)
	at com.sun.javafx.application.LauncherImpl.lambda$launchApplication1$146(javafx.graphics at 9-ea/LauncherImpl.java:838)
	at com.sun.javafx.application.PlatformImpl.lambda$runAndWait$160(javafx.graphics at 9-ea/PlatformImpl.java:351)
	at com.sun.javafx.application.PlatformImpl.lambda$null$158(javafx.graphics at 9-ea/PlatformImpl.java:320)
	at java.security.AccessController.doPrivileged(java.base at 9-ea/Native Method)
	at com.sun.javafx.application.PlatformImpl.lambda$runLater$159(javafx.graphics at 9-ea/PlatformImpl.java:319)
	at com.sun.glass.ui.InvokeLaterDispatcher$Future.run(javafx.graphics at 9-ea/InvokeLaterDispatcher.java:96)

This can be solved by adding a (qualified) export in the module-info of the module I'm trying to run (inspired by the helpful error message, nice!):

exports javamodularity.easytext.gui to javafx.graphics;

However, that's not really a satisfactory solution. Looks like LauncherImpl also needs to setup a readability relation on-the-fly, with the caveat that the class extending Application must always be exported by the application developer for this to work. Is this the solution we can expect, or are there any other plans for this situation?


Regards,
Sander