Run omxplayer "Always on top" from java code

Question

I have RaspberryPi2 (1GB RAM version) with Raspbian OS. I need to execute Omxplayer for play video. If i execute new process, Omxplayer is on a background. I need Omxplayer always on top. How to do it? Omxplayer has not switch to stay on top as for example mplayer (-ontop).

I found (https://askubuntu.com/questions/7377/how-to-start-an-app-with-always-on-top-set) wmctrl. I tried run java which execute omxplayer and after execute:

ProcessBuilder pb2 = new ProcessBuilder("bash", "-c", "wmctrl -a omxplayer");
Process p2 = pb2.start(); // Start the process.

but not working, probably because JavaFX working with framebuffer, not with the X11. Source: Why does my JavaFx application not have a frame when run on my RaspberryPi?

I am feeling that it is not possible tu run Omxplayer over java in fullscreen on RaspberryPi.

Code for run omxplayer as new process:

public class OmxPlayer {

    private int xPosition;
    private int yPosition;
    private int width;
    private int height;

    /** Constructor.
     * 
     * */
    OmxPlayer (int xPosition, int yPosition, int width, int height) {
        this.xPosition = xPosition;
        this.yPosition = yPosition;
        this.width = width;
        this.height = height;
     }

    public void play(String url){

        try {
            ProcessBuilder pb = new ProcessBuilder("bash", "-c", "omxplayer -r -o hdmi "+url);
            Process p = pb.start(); // Start the process.

            Log.write("I am playing file: "+url, Log.ENABLE_STDOUT);

            //p.waitFor(); // Wait for the process to finish.

            Log.write("File was played.", Log.ENABLE_STDOUT);
        } catch (Exception e) {
            StringWriter err = new StringWriter();
            e.printStackTrace(new PrintWriter(err));
            Log.write(err.toString(), Log.ENABLE_STDOUT);
        }
    }
}

Thank you.