Code:public String getMacAddress() { try { InetAddress a = connectedLocal; NetworkInterface n = NetworkInterface.getByInetAddress(a); byte[] m = n.getHardwareAddress(); StringBuilder sb = new StringBuilder(); for (int i = 0; i < m.length; i++) { sb.append(String.format("%02X%s", m[i], (i <m.length - 1) ? "-" : "")); } connectedMac = sb.toString(); } catch (SocketException e) { e.printStackTrace(); } return connectedMac; }