How to get the screen DPI in java?

Question

I am developing an app for which I need the screen DPI.. I checked a few forums and got a code snippet which goes as follows:

Dimension screen = java.awt.Too         


        

Answer 1

this code works for me on win10

import javafx.stage.Screen 

double getScaleFactor() {
        double trueHorizontalLines = Toolkit.getDefaultToolkit().getScreenSize().getHeight();
        double scaledHorizontalLines = Screen.getPrimary().getBounds().getHeight();
        double dpiScaleFactor = trueHorizontalLines / scaledHorizontalLines;
        return dpiScaleFactor;
    }

it uses some awt apis though

Answer 2

The problem is no one, not even the OS, knows the exact physical dimensions of the screen. You'd need to know that in order to calculate the PPI.

There's a display setting in the control panel where the user can manually specify the PPI and by default it's set to 96.