Tray icon simply not showing in java

Question

I've been trying all day to get my tray icon added, but it doesnt work. I have the icon file stored within the netbeans src/myproject/

I have tried a gazillion different paths, even direct ones to my files, but none seem to work. I'm pretty sure something in my code doesnt work, I simply can't see it.

public void createSystemTrayIcon() {

if (SystemTray.isSupported()) {
    SystemTray tray = SystemTray.getSystemTray();
    Image img = Toolkit.getDefaultToolkit().getImage("smallicon.ico");

    PopupMenu popup = new PopupMenu();

    final MenuItem menuExit = new MenuItem("Quit");

    MouseListener mouseListener =
        new MouseListener() {
        public void mouseClicked(MouseEvent e) {
            show();
        }

        public void mouseEntered(MouseEvent e) {
        }

        public void mouseExited(MouseEvent e) {
        }

        public void mousePressed(MouseEvent e) {
        }

        public void mouseReleased(MouseEvent e) {
        }
    };

    ActionListener exitListener =
        new ActionListener() {
        public void actionPerformed(ActionEvent e) {
            Runtime r = Runtime.getRuntime();
            System.out.println("Exiting...");
            r.exit(0);
        }
    };

    menuExit.addActionListener(exitListener);
    popup.add(menuExit);

    final TrayIcon trayIcon = new TrayIcon(img, "ESOLeaderboards", popup);

    ActionListener actionListener =
        new ActionListener() {
            public void actionPerformed(ActionEvent e) {
                trayIcon.displayMessage("ESOLeaderboards ","version: EU 1.0",
                        TrayIcon.MessageType.INFO);
        }
    };

    trayIcon.setImageAutoSize(true);
    trayIcon.addActionListener(actionListener);
    trayIcon.addMouseListener(mouseListener);

    try {
        tray.add(trayIcon);
    } catch (AWTException e) {
        System.err.println("TrayIcon could not be added.");
    }

} else {
    //  System Tray is not supported
}

}

Answer 1

Toolkit.getDefaultToolkit().getImage("smallicon.ico"); supports only JPG, PNG and GIF images.

It doesn't support ico images. Use another image.

Answer 2

The standard method of embedding images (and any other non-class resources) is to just put them in a package in the project, e.g. if you project is using com.myproject.myapp, then create a package (just a folder, really) images (under myapp) and put you image files there.

Access to those images (resources) is gained by using the ClassLoader methods getResource(name) and/or getResourceAsStream(name). For simplicity to get the right ClassLoader instance many prefer to also create a class (e.g. "Images") in that same package and define static constants there to access the resources by name (as simple as Images.CONSTANT_NAME). Project structure may look like this:

com.myproject.myapp
    images
        Images.class
        MyImage1.png

In the images class, constants can be defined either for the resource handle or the resources themselves:

public final static URL MY_IMAGE_1 = Images.class.getResource("MyImage1.png");

(The URL could then be passed to Toolkit). If an eager load of everything is desired/feasible the loaded images themselves:

public final static Image MY_IMAGE_1 = loadImage("MyImage1.png");

private static Image loadImage(String name) {
    URL url = Images.class.getClassLoader().getResource(name);
    Image img = Toolkit.getDefaultToolkit().getImage(url);
    // possible hack to force pre-loading of (toolkit) image in next line
    // new ImageIcon(img);
    return img;
}

Obviously I omitted all error handling from the examples, loading methods should include detailed error handling and reporting (logging/System.out and/or throwing appropiate exceptions) when something goes wrong.

These approaches will work in IDE as well as after creating a jar file for the program.

Answer 3

In windows 10, I've been able to view a 16 pixels PNG in the tray this way:

final URL resource = getClass().getResource("icon16.png");
final TrayIcon trayIcon = new TrayIcon(Toolkit.getDefaultToolkit().getImage(resource), "Application v0.1 tooltip");

It's "expected" that other OSes would down-scale a big icon, but I haven't tested it.