JDownloader 2 headless startup script

JDownloader2.sh

#!/bin/sh

DESC="JDownloader 2 Headless"
NAME=JDownloader2
PIDFILE=/var/run/$NAME.pid
COMMAND="/usr/bin/java -- -Djava.awt.headless=true -jar /home/osmc/jDownloader2/JDownloader.jar"
RUN_AS=osmc

d_start() {
    start-stop-daemon --start --quiet --background --make-pidfile --pidfile $PIDFILE --chuid $RUN_AS --exec $COMMAND
}

d_stop() {
    start-stop-daemon --stop --quiet --pidfile $PIDFILE
    if [ -e $PIDFILE ]
        then rm $PIDFILE
    fi
}

case $1 in
    start)
    echo -n "Starting $DESC: $NAME"
    d_start
    echo "."
    ;;
    stop)
    echo -n "Stopping $DESC: $NAME"
    d_stop
    echo "."
    ;;
    restart)
    echo -n "Restarting $DESC: $NAME"
    d_stop
    sleep 1
    d_start
    echo "."
    ;;
    *)
    echo "usage: $NAME {start|stop|restart}"
    exit 1
    ;;
esac

exit 0

Thanks for the startup script.
Problem is when the daemon is running on the background I can't start the JDownloader GUI.
How could I be able to run it on background but still open the GUI when needed?

I think is not possible, JDownloader avoids to open multiple windows, so, one process only. Use the web interface or the app of JDownloader.