public String getMAC() {
// 獲取連線狀態
ConnectivityManager mConnectivity = (ConnectivityManager)getSystemService(Context.CONNECTIVITY_SERVICE);
//檢查網路連線
NetworkInfo info = mConnectivity.getActiveNetworkInfo();
int netType = info.getType();
if (netType == ConnectivityManager.TYPE_WIFI) { //WIFI
WifiManager wifiManager = (WifiManager) getSystemService(Context.WIFI_SERVICE);
WifiInfo infoWIFI = wifiManager.getConnectionInfo();
// 返回WIFIMAC
return infoWIFI.getMacAddress();
} else {
// 返回乙太網MAC
return getPhoneMacAddress();
}
}

/**
 * Get the STB MacAddress
 */
public String getPhoneMacAddress() {
    try {
        return loadFileAsString("/sys/class/net/eth0/address").toUpperCase().substring(0, 17);
    } catch (IOException e) {
        e.printStackTrace();
        return null;
    }
}


public static String loadFileAsString(String filePath) throws java.io.IOException {
    StringBuffer fileData = new StringBuffer(1000);
    BufferedReader reader = new BufferedReader(new FileReader(filePath));
    char[] buf = new char[1024];
    int numRead = 0;
    while ((numRead = reader.read(buf)) != -1) {
        String readData = String.valueOf(buf, 0, numRead);
        fileData.append(readData);
    }
    reader.close();
    return fileData.toString();
}