效果图

           悬停：

            

​​         SystemTray tray = SystemTray.getSystemTray();
        PopupMenu pm = new PopupMenu();
        //设置图标
        BufferedImage image = ImageIO.read(Main.class
                .getResourceAsStream("trayicon.png"));
        //设置右键菜单 
        MenuItem mi = new MenuItem("exit");
        //右键菜单监听
        mi.addActionListener(e -> {
            //点击右键菜单退出程序
           System.exit(0);
        });
        pm.add(mi);
        //设置悬停提示信息
        TrayIcon trayIcon = new TrayIcon(image, "screenShot", pm);
        tray.add(trayIcon);