Flutter Dio helper class

gistfile1.txt

Future<Dio> getInstance() async {
    final String token =
        await fluxPreference.readString(PreferenceConstants.USER_TOKEN, null);
    Map<String, dynamic> headers = {};
    headers['Content-Type'] = 'application/json';
    headers['RESPONSE-VERSION'] = '2';
    if (token != null) headers['Authorization'] = 'Bearer $token';
    print("Token ============================ $token");

    return Dio(BaseOptions(
      baseUrl: baseUrl,
      responseType: ResponseType.json,
      connectTimeout: 30000,
      receiveTimeout: 30000,
    ))
      ..options.headers = headers
      ..interceptors.addAll([
        LoggingInterceptor.loggingInterceptor(),
      ]);
  }

Future<Response> get(String url) async {
    try {
      final client = await getInstance();
      return await client.get(url);
    } on DioError catch (e) {
      // Handle error
      throw Exception(e.message);
    } catch (e) {
      throw Exception(e.toString());
    }
  }

  Future<Response> post(String url, dynamic data) async {
    try {
      final client = await getInstance();
      return await client.post(url, data: data);
    } on DioError catch (e) {
      // Handle error
      throw Exception(e.message);
    } catch (e) {
      throw Exception(e.toString());
    }
  }

  Future<Response> put(String url, dynamic data) async {
    try {
      final client = await getInstance();
      return await client.put(url, data: data);
    } on DioError catch (e) {
      throw Exception(e.message);
    } catch (e) {
      throw Exception(e.toString());
    }
  }

  Future<Response> delete(String url) async {
    try {
      final client = await getInstance();
      return await client.delete(url);
    } on DioError catch (e) {
      throw Exception(e.message);
    } catch (e) {
      throw Exception(e.toString());
    }
  }