A DESCRIPTION OF THE PROBLEM :
It would be convenient if we could be able to the font path for java.awt.Font class.

Example:
// Get the font
Font font = new Font("Arial Black", Font.PLAIN, 1);
String fontPath = font.getFontPath(); --> This method would Return "C:\Windows\Fonts\ariblk.ttf"

In my case, I would like to copy an installed font and paste in an another directory.

From what I know, the currently only method to do this is to use this old librairies (it is deprecated):
sun.font.PhysicalFont;

Here is an example of code to get the font path:
    public String findFont(Font font) {

        /*Font2D f2d = FontManagerFactory.getInstance().findFont2D(f.getFontName(), f.getStyle(),
                FontManager.LOGICAL_FALLBACK).handle.font2D;*/

        Font2D f2d = FontUtilities.getFont2D(font);
        String fontPath = "";
        try {
            Field platName = PhysicalFont.class.getDeclaredField("platName");
            platName.setAccessible(true);
            fontPath = (String) platName.get(f2d);
            platName.setAccessible(false);
        } catch (NoSuchFieldException | IllegalAccessException e) {
            System.out.println(e.getLocalizedMessage());
        }

        return fontPath;
    }

The problem of this librairie is that it only take look in "C:\Windows\Fonts" folder, so it does not look in "%userprofile%\AppData\Local\Microsoft\Windows\Fonts" folder which is a pretty big problem.