I am Making a Simple App using JavaFX UI, The app simply just do that:
The system tray is not supported in JavaFX yet. You could track the progress on this task under the following JIRA issue: https://bugs.openjdk.java.net/browse/JDK-8090475
The issue also provides a workaround, which could be used in JavaFX 8 to get the basic support.
The feature is not planned for JavaFX 8, so it might be released in one of the following updates or even in JavaFX 9.