Can't Change Default Java Image (JFrame.setIconImage)

Issue

I am trying to change the icon of the Java application but nothing seems to work.

I am trying to get image from resources path using:

getClass().getResource("/AppIcon.png")

Sometimes I get an error like URL not found.

Solution

Solution; Everything works for windows but I am using Mac :D So I started to look around Taskbar class comes with awt package and found the solution (Thanks to flohall)

try {
    var image = new ImageIcon(Objects.requireNonNull(Main.class.getResource("/AppIcon.png")));
    frame.setIconImage(image.getImage());
    if (System.getProperty("os.name").startsWith("Mac") || System.getProperty("os.name").startsWith("Darwin")) {
        Taskbar taskbar = Taskbar.getTaskbar();
        try {
            taskbar.setIconImage(image.getImage());
        } catch (final UnsupportedOperationException e) {
            System.out.println("Can't set taskbar icon.");
        } catch (final SecurityException e) {
            System.out.println("Warning. Can't set taskbar icon due to security exceptions.");
        }
    }
} catch (NullPointerException e) {
    e.printStackTrace();
}

So we are telling the taskbar to change its icon using built-in awt Taskbar class on taskbar.setIconImage(image.getImage());. And that solves most of the things I've needed for.

Answered By - devsimsek