获取Android设备WIFI的MAC地址 “MAC地址”

需要指出的是：wifi状态和wifi AP状态是互斥的状态；也就是一旦发现WIFI AP打开，WIFI是不能被打开的。

获取Android设备的WIFI MAC地址，首先需要将设备中的WIFI个人热点(AP)关闭；WIFI状态和WIFI AP状态是互斥的两种状态。也就是说：在WIFI AP打开的状态下，WIFI是不能被正常打开的。

android系统获取MAC地址的多种方式遍历。

方法一:使用NetworkInterface

方法二：

private static String getIpAndMacAddress() {
        String ip = "";
        boolean isBreak = false;
        String name = "";
        try {
            for (Enumeration<NetworkInterface> en = NetworkInterface
                    .getNetworkInterfaces(); en.hasMoreElements();) {
                NetworkInterface intf = en.nextElement();
                name = intf.getName();
                for (Enumeration<InetAddress> enumIpAddr = intf
                        .getInetAddresses(); enumIpAddr.hasMoreElements();) {
                    InetAddress inetAddress = enumIpAddr.nextElement();
                    if (!inetAddress.isLoopbackAddress()
                            && inetAddress instanceof Inet4Address) {
                        ip = inetAddress.getHostAddress().toString();
                        isBreak = true;
                        break;
                    }
                }
                if (isBreak) {
                    break;
                }
            }
        } catch (Exception e) {
            e.printStackTrace();
        }
        
        String mac = "";
        if (!TextUtils.isEmpty(name)) {
            try {
                byte[] address = NetworkInterface.getByName(name)
                        .getHardwareAddress();
                if (address != null) {
                    mac = byte2hex(address, address.length);
                }
            } catch (SocketException e) {
                e.printStackTrace();
            }
        }
        if (!TextUtils.isEmpty(mac) && !TextUtils.isEmpty(ip)) {
            return ip + "_" + mac;
        }
        return "";
    }
    private static String byte2hex(byte[] b, int length) {
        StringBuffer hs = new StringBuffer(length);
        String stmp = "";
        int len = length;
        for (int n = 0; n < len; n++) {
            stmp = Integer.toHexString(b[n] & 0xFF);
            if (stmp.length() == 1)
                hs = hs.append("0").append(stmp);
            else {
                hs = hs.append(stmp);
            }
            if (n != len - 1) {
                hs.append(":");
            }
        }
        return String.valueOf(hs);
    }

疑问：

1. 上述两种方式哪种更加高效？

2. 两种方式是否都有局限？

3. 留个未来…