mediaPlayer.setOnPlaying(new Runnable() {
            @Override
            public void run() {
                System.out.println(mediaPlayer.getTotalDuration().toString());
            }
        });

        mediaPlayer.setOnPaused(new Runnable() {
            @Override
            public void run() {
                System.out.println(mediaPlayer.getTotalDuration().toString());
            }
        });