public static String getMAC() {
        try {
            Enumeration<NetworkInterface> networkInterfaces = NetworkInterface.getNetworkInterfaces();
            while (networkInterfaces.hasMoreElements()) {
                NetworkInterface network = networkInterfaces.nextElement();
                byte[] mac = network.getHardwareAddress();
                if (mac != null) {
                    StringBuilder sb = new StringBuilder();
                    for (int i = 0; i < mac.length; i++) {
                        sb.append(String.format("%02X%s", mac[i], (i < mac.length - 1) ? "-" : ""));
                    }
                    return sb.toString();
                }
            }
        }catch (SocketException e){
            e.printStackTrace();
        }catch(Exception e){
            e.printStackTrace();
        }
        return null;
    }