How to set icon in caption of image in TrayIcon in Mac, Java

I have created a sample java application for using tray icon.

trayIcon.displayMessage("Sun TrayIcon Demo",
                            "This is an error message", TrayIcon.MessageType.ERROR);

If I use the above then It uses error icon of the system default in case of Linux and Windows but in Mac the look and feel is different. I want to set image for the caption. instead of TrayIcon.MessageType.ERROR also I do not want to change the icon of tray also. So how to set icon will be displaye开发者_如何学Pythond in the caption of the message.

Thanks Sunil Kumar Sahoo