使用 Dio 中的 Interceptor for Flutter 刷新 Token

我用拦截器解决了这个问题，方法如下:-

  Future<Dio> getApiClient() async {
    token = await storage.read(key: USER_TOKEN);
    _dio.interceptors.clear();
    _dio.interceptors
        .add(InterceptorsWrapper(onRequest: (RequestOptions options) {
      // Do something before request is sent
      options.headers["Authorization"] = "Bearer " + token;
      return options;
    },onResponse:(Response response) {
        // Do something with response data
        return response; // continue
    }, onError: (DioError error) async {
      // Do something with response error
      if (error.response?.statusCode == 403) {
        _dio.interceptors.requestLock.lock();
        _dio.interceptors.responseLock.lock();
        RequestOptions options = error.response.request;
        FirebaseUser user = await FirebaseAuth.instance.currentUser();
        token = await user.getIdToken(refresh: true);
        await writeAuthKey(token);
        options.headers["Authorization"] = "Bearer " + token;

        _dio.interceptors.requestLock.unlock();
        _dio.interceptors.responseLock.unlock();
        return _dio.request(options.path,options: options);
      } else {
        return error;
      }
    }));
    _dio.options.baseUrl = baseUrl;
    return _dio;
  }

DIO 4.0.0支持

    dio.interceptors.add(
          InterceptorsWrapper(
            onRequest: (request, handler) {
              if (token != null && token != '')
                request.headers['Authorization'] = 'Bearer $token';
              return handler.next(request);
            },
            onError: (e, handler) async {
              if (e.response?.statusCode == 401) {
                try {
                  await dio
                      .post(
                          "https://refresh.api",
                          data: jsonEncode(
                              {"refresh_token": refreshtoken}))
                      .then((value) async {
                    if (value?.statusCode == 201) {
                      //get new tokens ...
                      print("access token" + token);
                      print("refresh token" + refreshtoken);
                      //set bearer
                      e.requestOptions.headers["Authorization"] =
                          "Bearer " + token;
                      //create request with new access token
                      final opts = new Options(
                          method: e.requestOptions.method,
                          headers: e.requestOptions.headers);
                      final cloneReq = await dio.request(e.requestOptions.path,
                          options: opts,
                          data: e.requestOptions.data,
                          queryParameters: e.requestOptions.queryParameters);
    
                      return handler.resolve(cloneReq);
                    }
                    return e;
                  });
                  return dio;
                } catch (e, st) {
                  
                }
              }
           },
        ),
    );