Problem using JavaFX Application class

[Kevin Rushforth]

Actually, I don't see any problem here, other than that we will need to 
document that if you want to launch a modular javafx application, you 
need to export the package containing your main class. This is an 
extension of what is needed today, which is that the class be public. If 
you use FXML, then the same thing would apply to any class that you want 
FXML to access.

-- Kevin


David Hill wrote:
> On 2/23/16, 3:37 PM, Sander Mak wrote:
>> Hi,
>
> Sander,
>     we may not have tested Jigsaw with the path you are trying to take 
> here.
>
> Certainly the common path of a class extending Application will launch 
> properly, and I have been trudging through our test cases working on 
> some odder paths. What I have not been doing in these paths is dealing 
> with a new module, though I would think that would behave similarly to 
> the unnamed module.
>
> It could be that your added complexity here has not been properly 
> dealt with in our FX code.
>
> Do you have a "simple" test case that shows this error?
>
> Looking at the exception I see a lot of stuff going on, and it is hard 
> to see the root right away.
>
> With modules, we have to add read edge code in certain spots when our 
> code has to reach out of the module to a module it does not already 
> know about.
>
> This is the hint here:
>
> (in module javafx.graphics) cannot access class 
> javamodularity.easytext.gui.Main (in module javamodularity.easytext.gui)
>
> Our FX module javafx.graphics cannot see into your module.
>
> The question becomes one of where, and order of operations.
>
> Dave
>
>
>>
>> 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
>
>