Using java.awt.Toolkit.getDefaultToolkit().getScreenSize() reflectively causes InaccessibleObjectException

[Phil Race]

ah yes .. I can see how one might code that way.
I don't know how common a problem this is, but
such code will need to be updated.

----
import java.awt.Toolkit;

public class TK8 {
     public static void main(String args[]) throws Exception {
        Toolkit tk = Toolkit.getDefaultToolkit();
        Class tkc = tk.getClass();
        System.out.println(tkc);
        java.lang.reflect.Method m = tkc.getMethod("getScreenSize");
        System.out.println(m.invoke(tk));
     }
}

~/jdk8u45/bin/java TK8
class sun.awt.X11.XToolkit
java.awt.Dimension[width=1920,height=1200]

~/jdk9b142/bin/java TK8
class sun.awt.X11.XToolkit
Exception in thread "main" java.lang.NoSuchMethodException: 
sun.awt.X11.XToolkit.getScreenSize()
     at java.lang.Class.getDeclaredMethod(java.base at 9-ea/Class.java:2318)
     at TK8.main(TK8.java:8)
----

-phil.

On 01/05/2017 11:34 AM, Alex Buckley wrote:
> Rony mentioned "the returned Toolkit is of type sun.awt.X11.XToolkit" 
> which suggests that he is calling getClass() on the result of 
> getDefaultToolkit(), and then reflecting further on that Class object 
> and its Methods. As has been discussed previously on jigsaw-dev, this 
> won't work for implementation classes; it's necessary to reflect over 
> exported classes and interfaces instead.
>
> Alex
>
> On 1/5/2017 11:22 AM, Phil Race wrote:
>> This should be discussed on jigsaw-dev.
>>
>> But can you share your code ? -  since the following works for me :
>>
>> import java.awt.Toolkit;
>>
>> public class TK {
>>      public static void main(String args[]) throws Exception {
>>         Toolkit tk = Toolkit.getDefaultToolkit();
>>         Class tkc = Class.forName("java.awt.Toolkit");
>>         java.lang.reflect.Method m = tkc.getMethod("getScreenSize");
>>         System.out.println(m.invoke(tk));
>>      }
>> }
>>
>> ~/jdk9b142/bin/java TK
>> java.awt.Dimension[width=1920,height=1200]
>>
>> -phil.
>>
>> On 01/05/2017 11:03 AM, Rony G. Flatscher wrote:
>>> Experimenting with further scripts indicates that this is a systematic
>>> problem whenever the official
>>> APIs return members that are not made available to an unnamed module:
>>> e.g. JavaFX some
>>> "com.sun.javafx.collections.VetoableListDecorator" or in a "plain"
>>> awt/swing app some
>>> "sun.java2d.SungGraphics2D".
>>>
>>> ---rony
>>>
>>> On 05.01.2017 19:42, Rony G. Flatscher wrote:
>>>> Trying to run a program that gets the screen dimensions using
>>>> java.awt.Toolkit.getDefaultToolkit().getScreenSize() reflectively.
>>>>
>>>> On a 64-bit Ubuntu the returned Toolkit is of type
>>>> sun.awt.X11.XToolkit. Reflectively invoking its
>>>> method getScreenSize() causes the following exception to be thrown on
>>>> 9-ea+134:
>>>>
>>>>      java.lang.reflect.InaccessibleObjectException: unable to make
>>>> member of class sun.awt.SunToolkit
>>>>      accessible: module java.desktop does not export sun.awt to
>>>> unnamed module ...
>>>>
>>>> A little bit baffled as this is from a script that has been working
>>>> flawlessly throughout more than
>>>> a decade on various Java versions and which employs documented public
>>>> methods only (the sun.awt
>>>> object is returned by java.awt.Toolkit). Is this a known
>>>> "legacy"problem :) that I could circumvent
>>>> somehow or a bug that needs to be reported?
>>>>
>>>> ---rony
>>>>
>>