How to find real display density (DPI) from Java code?

Question

I\'m going to do some low-level rendering stuff, but I need to know real display DPI for making everything of correct size.

I\'ve found one way to do this: jav

Answer 1

Here's an example adopted from @sarge-borsch that won't throw compile errors on Windows and Linux.

public static int getScaleFactor() {
    try {
        // Use reflection to avoid compile errors on non-macOS environments
        Object screen = Class.forName("sun.awt.CGraphicsDevice").cast(GraphicsEnvironment.getLocalGraphicsEnvironment().getDefaultScreenDevice());
        Method getScaleFactor = screen.getClass().getDeclaredMethod("getScaleFactor");
        Object obj = getScaleFactor.invoke(screen);
        if (obj instanceof Integer) {
            return ((Integer)obj).intValue();
        }
    } catch (Exception e) {
        System.out.println("Unable to determine screen scale factor.  Defaulting to 1.");
    }
    return 1;
}