get unique device id android

complex device id

/**
     * get unique device id, reuire permission READ_PHONE_STATE
     *
     * @param context
     * @return unique id string
     */
    public static String getDeviceId(Context context) {
        String deviceID = null;

        // TODO: check from pref if null -> generate
        String PREFERENCE_FILE_NAME = "preference_deviceXXX";
        String KEY_PREF = "uiid";

        // don't generate uiid if exist in preference
        String saved_id = (String) getPreferenceValue(context, PREFERENCE_FILE_NAME, KEY_PREF);
        if (saved_id == null || saved_id == "") {
            TelephonyManager telephonyManager = (TelephonyManager) context.getSystemService(Context.TELEPHONY_SERVICE);
            String id = telephonyManager.getDeviceId();
            // tablet device will return null
            if (id == null || id == "") {
                // maybe change when factory reset
                String id1 = Settings.Secure.ANDROID_ID;
                if (id1 == null || id1 == "") {
                    // last solution is using random string
                    deviceID = UUID.randomUUID().toString();
                } else {
                    deviceID = id1;
                }
            } else {
                deviceID = id;
            }

            // after generate uiid, save for use later
            writePreference(context, PREFERENCE_FILE_NAME, KEY_PREF, deviceID);
        } else {
            deviceID = saved_id;
        }
        return deviceID;
    }

get device ID

/**
     * get device id from base64 wifi Mac or android_id
     * @param context {@link android.content.Context}
     * @return DeviceID unique android id
     */
    public static String getDeviceID(Context context) {
        SharedPreferences shapref =  context.getSharedPreferences(AppConfig.PREFERENCE_NAME, Context.MODE_PRIVATE);

        // get device id if available
        String deviceID = shapref.getString(AppConfig.KEY_PREF_DEVICE_ID, null);
        if(TextUtils.isEmpty(deviceID)){
            SharedPreferences.Editor editor = shapref.edit();

            // init device id mac wifi (nor android_id)
            WifiManager wimanager = (WifiManager) context.getSystemService(Context.WIFI_SERVICE);
            String macAddress = null;
            if(wimanager.isWifiEnabled()){
                macAddress = wimanager.getConnectionInfo().getMacAddress();
            }
            if (macAddress == null) {
                macAddress = Settings.Secure.getString(context.getContentResolver(), Settings.Secure.ANDROID_ID);
            }

            // base64 encode for text
            macAddress = Base64.encodeToString(macAddress.getBytes(), Base64.NO_PADDING);

            // save to pref for re-use
            editor.putString(AppConfig.KEY_PREF_DEVICE_ID, macAddress);
            editor.commit();
            deviceID = macAddress;
        }

        return deviceID.trim();
    }