How to get connected device count in hotspot(AP) programmatically [Android]

Am working on a application which need to show the hotspot details including the number of device connected to the hotspot

I tried this but not worked ,

private int countNumMac()
    {
        int macCount =0;
        BufferedReader br = null;
        try {
            br = new BufferedReader(new FileReader("/proc/net/arp"));
            String line;

            System.out.println(br.toString());
            while ((line = br.readLine()) != null) {

                String[] splitted = line.split(" +");
                System.out.println("splitted :"+splitted);

                if (splitted != null && splitted.length >= 4) {
                    // Basic sanity check
                    String mac = splitted[3];
                    if (mac.matches("..:..:..:..:..:..")) {
                        macCount++;
                    } 
                }
            }
        } catch (Exception e) {
            e.printStackTrace();
        } finally {
            try {
                br.close();
            } catch (IOException e) {
                e.printStackTrace();
            }
        }
        if(macCount == 0)
            return 0;
        else
            return macCount-1; 
    }

Is there any other method to count the number of device connected to hotspot..

from How to get connected device count in hotspot(AP) programmatically [Android]