Understanding the com.sun.* APIs being (ab)used by the community

[Dr. Michael Paus]

As nobody has stated it explicitly so far I would like to ask what will 
happen
to classes in Java9 which access methods that are within the javafx 
namespace but
are declared private? Will code like this still work or not?

     public static double getPixelScale(Screen screen) throws 
NoSuchMethodException, SecurityException, IllegalAccessException, 
IllegalArgumentException, InvocationTargetException {
         Method m = Screen.class.getDeclaredMethod("getScale");
         m.setAccessible(true);
         return ((Float) m.invoke(screen)).doubleValue();
     }

This hack for example is currently necessary because there is no other 
way to get at
the current pixel scale of a HiDPI screen.