flutter dio(4.0.0) 处理令牌过期(处理401)

flutter dio(4.0.0) handling token expiration (handling 401)

我已经声明了一个 class 来使用 flutter Dio 发出 api 请求,如下所示。

class DioUtil {
  static Dio _instance;

  static Dio getInstance() {
    if (_instance == null) {
      _instance = createDio();
    }
    return _instance;
  }

  static Dio createDio() {
    var dio = Dio();
    dio.interceptors.add(InterceptorsWrapper(onRequest: (options, handler) {
      // Do something before request is sent
      return handler.next(options); //continue
    }, onResponse: (response, handler) {
      // Do something with response data
      return handler.next(response); // continue
    }, onError: (DioError e, handler) async {
      if (e.response != null) {
        if (e.response.statusCode == 401) {
          var dio = DioUtil.getInstance();
          dio.interceptors.requestLock.lock();
          dio.interceptors.responseLock.lock();
          RequestOptions requestOptions = e.requestOptions;

          await refreshToken();
          Repository repository = Repository();
          var accessToken = await repository.readData("accessToken");
          final opts = new Options(
            method: requestOptions.method
          );
          dio.options.headers["Authorization"] = "Bearer " + accessToken;
          dio.interceptors.requestLock.unlock();
          dio.interceptors.responseLock.unlock();
          dio.request(requestOptions.path,
              options: opts,
              data: requestOptions.data,
              queryParameters: requestOptions.queryParameters);
        }//TODO: handle else clause
      }
    }));
    return dio;
  }

  static refreshToken() async {
    Response response;
    Repository repository = Repository();
    var dio = Dio();
    final Uri apiUrl = Uri.parse(BASE_PATH + "auth/reIssueAccessToken");
    var refreshToken = await repository.readData("refreshToken");
    dio.options.headers["Authorization"] = "Bearer " + refreshToken;
    response = await dio.postUri(apiUrl);
    if (response.statusCode == 200) {
      LoginResponse loginResponse =
          LoginResponse.fromJson(jsonDecode(response.toString()));
      repository.addValue('accessToken', loginResponse.data.accessToken);
      repository.addValue('refreshToken', loginResponse.data.refreshToken);
    } else {
      print(response.toString());
    }
  }
}

我使用的是 flutter bloc 模式,我的 bloc 如下。

class OurClassBloc extends Bloc<OurClassEvent, OurClassState> {
  OurClassBloc(OurClassState initialState) : super(initialState);
  Repository repository = Repository();

  @override
  Stream<OurClassState> mapEventToState(
    OurClassEvent event,
  ) async* {
    if (event is GetClasses) {
      yield* _getClassCategories(event);
    }
  }

  Stream<OurClassState> _getClassCategories(GetClasses event) async* {
    Response response;
    var dio = DioUtil.getInstance();
    final String apiUrl = (BASE_PATH + "classCategories");
    var accessToken = await repository.readData("accessToken");
    Map<String, dynamic> map = {"active": event.active};
    dio.options.headers["Authorization"] = "Bearer " + accessToken;
    dio.options.headers["Accept"] = "*/*";
    try {
      response = await dio.get(apiUrl, queryParameters: map);
      if (response.statusCode == 200) {
        OurClassResponse loginResponse =
            OurClassResponse.fromJson(jsonDecode(response.toString()));
        yield OurClassSuccess(loginResponse);
      }
      if (response.statusCode >= 400) {
        yield OurClassFailed();
      }
    } catch (e) {
      yield OurClassFailed();
    }
  }
}

当我使用有效的访问令牌发出请求时,我在 bloc class 中得到 200 状态代码并且 api 有效 fine.when 令牌已过期,dio class 正确获取新令牌,使用新令牌成功进行相同的 api 调用,在下面的回调中我也得到正确的响应。

onResponse: (response, handler) {
  return handler.next(response);
}

但集团没有回应 class。虽然它通过调用 return handler.next(response); 返回了响应,但它并没有到达 _getClassCategories 中的 response 变量 method.I 期望正确的响应应该到达 response 中的变量两种情况下的 bloc class:

  1. 使用有效令牌进行 api 调用。
  2. 使用过期令牌进行 api 调用。

但只有场景 1 在我的代码中有效,希望这里有人可以帮助我解决这个问题。

编辑- 这适用于 dio 以前的版本 (3.0.10) -

          dio.request(requestOptions.path,
              options: opts,
              data: requestOptions.data,
              queryParameters: requestOptions.queryParameters);

此行创建了一个与原始请求无关的新请求。如果请求成功,则没有代码监听响应。如果您希望原始调用者收到任何内容,您需要将响应转发给原始处理程序:

          try {
              final response = await dio.request(requestOptions.path,
                  options: opts,
                  data: requestOptions.data,
                  queryParameters: requestOptions.queryParameters);
              handler.resolve(response);
          } on DioError catch (error) {
              handler.next(error); // or handler.reject(error);
          }

另外,在非 401 情况下也一定要将错误转发给处理程序。 Dio 4.0.0 拦截器不会自动转发任何内容。