Flutter 網絡請求 Dio 封裝

時間 2020-03-25

原文原文鏈接

在Flutter項目中使用網絡請求的方式大體可分爲兩種，分別是Dart原生的網絡請求 HttpClient類以及第三方開源的網絡請求庫。在Dart社區開源的第三方http請求庫中Flutter中文網開源的Dio庫人氣最高。
下面咱們先來比較下這兩種網絡請求方式，而後再看怎麼基於 Dio庫封裝方便使用的網絡請求工具類HttpManager。git

網絡請求庫比較

HttClient類

Dart IO庫中提供了用於發起Http請求的一些類，咱們能夠直接使用HttpClient來發起請求。使用HttpClient發起請求分爲五步：github

建立一個HttpClient

HttpClient httpClient = new HttpClient();
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打開Http鏈接，設置請求頭

HttpClientRequest request = await httpClient.getUrl(uri);
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這一步可使用任意Http Method，如httpClient.post(...)、httpClient.delete(...)等。若是包含Query參數，能夠在構建uri時添加，如：json

Uri uri=Uri(scheme: "https", host: "flutterchina.club", queryParameters: {
    "xx":"xx",
    "yy":"dd"
  });
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經過HttpClientRequest能夠設置請求header，如：api

request.headers.add("user-agent", "test");
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若是是post或put等能夠攜帶請求體方法，能夠經過HttpClientRequest對象發送request body，如：bash

String payload="...";
request.add(utf8.encode(payload)); 
//request.addStream(_inputStream); //能夠直接添加輸入流
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等待鏈接服務器

HttpClientResponse response = await request.close();
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這一步完成後，請求信息就已經發送給服務器了，返回一個HttpClientResponse對象，它包含響應頭（header）和響應流(響應體的Stream)，接下來就能夠經過讀取響應流來獲取響應內容。服務器

讀取響應內容

String responseBody = await response.transform(utf8.decoder).join();
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咱們經過讀取響應流來獲取服務器返回的數據，在讀取時咱們能夠設置編碼格式，這裏是utf8。restful

請求結束，關閉HttpClient

httpClient.close();
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關閉client後，經過該client發起的全部請求都會停止。網絡

以上的步驟是dart原生網絡HttpClient使用方式，能夠發現直接使用HttpClient發起網絡請求是比較麻煩的，不少事情都得手動處理，若是再涉及到文件上傳/下載、Cookie管理等就會變得很是繁瑣，而且HttpClient自己功能較弱，不少經常使用功能都不支持。app

Dio庫

dio是一個強大的Dart Http請求庫，支持Restful API、FormData、攔截器、請求取消、Cookie管理、文件上傳/下載、超時等...異步

pubspec.yaml 添加依賴

dependencies:
  dio: ^x.x.x #請使用pub上的最新版本
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導入引用並建立dio 實例

import 'package:dio/dio.dart';
Dio dio =  Dio();
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接下來就能夠經過 dio實例來發起網絡請求了，注意，一個dio實例能夠發起多個http請求，通常來講，APP只有一個http數據源時，dio應該使用單例模式。

發起網絡請求

Get 請求

Response response;
response=await dio.get("/test?id=12&name=cheney")
print(response.data.toString());
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Post請求

Response response;
response=await dio.post("/test",data:{"id":12,"name":"cheney"})
print(response.data.toString());
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以上就是Dio庫網絡請求的基本使用，是否是很簡單，除了這些基本的用法，dio還支持請求配置、攔截器等，官方資料比較詳細，故在這裏再也不贅述，詳情能夠參考dio主頁：github.com/flutterchin… 。

封裝Dio工具類

爲何要封裝 dio

作一些公共處理，方便靈活的使用。

作那些封裝

統一處理請求前綴；（www.xx.com/api/v1 不用每一個請求都加前綴）
統一輸出請求或響應信息；
統一錯誤信息處理；
兼容多種網絡請求、支持文件上傳、下載；
支持同步回調與異步Future 兩種形式
返回數據自動轉json格式並默認解析公共數據模型；

類名	描述
HttpManager	網絡請求管理類
HttpError	網絡請求統一錯誤類
LogInterceptor	網絡請求工具類

import 'dart:core';

import 'package:connectivity/connectivity.dart';
import 'package:dio/dio.dart';
import 'package:flutter/material.dart';
import 'package:flutter_common_utils/http/http_error.dart';
import 'package:flutter_common_utils/log_util.dart';

///http請求成功回調
typedef HttpSuccessCallback<T> = void Function(dynamic data);

///失敗回調
typedef HttpFailureCallback = void Function(HttpError data);

///數據解析回調
typedef T JsonParse<T>(dynamic data);


/// @desc  封裝 http 請求
/// @time 2019/3/15 10:35 AM
/// @author Cheney
class HttpManager {
  ///同一個CancelToken能夠用於多個請求，當一個CancelToken取消時，全部使用該CancelToken的請求都會被取消，一個頁面對應一個CancelToken。
  Map<String, CancelToken> _cancelTokens =  Map<String, CancelToken>();

  ///超時時間
  static const int CONNECT_TIMEOUT = 30000;
  static const int RECEIVE_TIMEOUT = 30000;

  /// http request methods
  static const String GET = 'get';
  static const String POST = 'post';

  Dio _client;

  static final HttpManager _instance = HttpManager._internal();

  factory HttpManager() => _instance;

  Dio get client => _client;

  /// 建立 dio 實例對象
  HttpManager._internal() {
    if (_client == null) {
      /// 全局屬性：請求前綴、鏈接超時時間、響應超時時間
      BaseOptions options = BaseOptions(
        connectTimeout: CONNECT_TIMEOUT,
        receiveTimeout: RECEIVE_TIMEOUT,
      );
      _client = Dio(options);
    }
  }

  ///初始化公共屬性
  ///
  /// [baseUrl] 地址前綴
  /// [connectTimeout] 鏈接超時趕時間
  /// [receiveTimeout] 接收超時趕時間
  /// [interceptors] 基礎攔截器
  void init(
      {String baseUrl,
      int connectTimeout,
      int receiveTimeout,
      List<Interceptor> interceptors}) {
    _client.options = _client.options.merge(
      baseUrl: baseUrl,
      connectTimeout: connectTimeout,
      receiveTimeout: receiveTimeout,
    );
    if (interceptors != null && interceptors.isNotEmpty) {
      _client.interceptors..addAll(interceptors);
    }
  }

  ///Get網絡請求
  ///
  ///[url] 網絡請求地址不包含域名
  ///[params] url請求參數支持restful
  ///[options] 請求配置
  ///[successCallback] 請求成功回調
  ///[errorCallback] 請求失敗回調
  ///[tag] 請求統一標識，用於取消網絡請求
  void get({
    @required String url,
    Map<String, dynamic> params,
    Options options,
    HttpSuccessCallback successCallback,
    HttpFailureCallback errorCallback,
    @required String tag,
  }) async {
    _request(
      url: url,
      params: params,
      method: GET,
      successCallback: successCallback,
      errorCallback: errorCallback,
      tag: tag,
    );
  }

  ///post網絡請求
  ///
  ///[url] 網絡請求地址不包含域名
  ///[data] post 請求參數
  ///[params] url請求參數支持restful
  ///[options] 請求配置
  ///[successCallback] 請求成功回調
  ///[errorCallback] 請求失敗回調
  ///[tag] 請求統一標識，用於取消網絡請求
  void post({
    @required String url,
    data,
    Map<String, dynamic> params,
    Options options,
    HttpSuccessCallback successCallback,
    HttpFailureCallback errorCallback,
    @required String tag,
  }) async {
    _request(
      url: url,
      data: data,
      method: POST,
      params: params,
      successCallback: successCallback,
      errorCallback: errorCallback,
      tag: tag,
    );
  }

  ///統一網絡請求
  ///
  ///[url] 網絡請求地址不包含域名
  ///[data] post 請求參數
  ///[params] url請求參數支持restful
  ///[options] 請求配置
  ///[successCallback] 請求成功回調
  ///[errorCallback] 請求失敗回調
  ///[tag] 請求統一標識，用於取消網絡請求
  void _request({
    @required String url,
    String method,
    data,
    Map<String, dynamic> params,
    Options options,
    HttpSuccessCallback successCallback,
    HttpFailureCallback errorCallback,
    @required String tag,
  }) async {
    //檢查網絡是否鏈接
    ConnectivityResult connectivityResult =
        await (Connectivity().checkConnectivity());
    if (connectivityResult == ConnectivityResult.none) {
      if (errorCallback != null) {
        errorCallback(HttpError(HttpError.NETWORK_ERROR, "網絡異常，請稍後重試！"));
      }
      LogUtil.v("請求網絡異常，請稍後重試！");
      return;
    }

    //設置默認值
    params = params ?? {};
    method = method ?? 'GET';

    options?.method = method;

    options = options ??
        Options(
          method: method,
        );

    url = _restfulUrl(url, params);

    try {
      CancelToken cancelToken;
      if (tag != null) {
        cancelToken =
            _cancelTokens[tag] == null ? CancelToken() : _cancelTokens[tag];
        _cancelTokens[tag] = cancelToken;
      }

      Response<Map<String, dynamic>> response = await _client.request(url,
          data: data,
          queryParameters: params,
          options: options,
          cancelToken: cancelToken);
      String statusCode = response.data["statusCode"];
      if (statusCode == "0") {
        //成功
        if (successCallback != null) {
          successCallback(response.data["data"]);
        }
      } else {
        //失敗
        String message = response.data["statusDesc"];
        LogUtil.v("請求服務器出錯：$message");
        if (errorCallback != null) {
          errorCallback(HttpError(statusCode, message));
        }
      }
    } on DioError catch (e, s) {
      LogUtil.v("請求出錯：$e\n$s");
      if (errorCallback != null && e.type != DioErrorType.CANCEL) {
        errorCallback(HttpError.dioError(e));
      }
    } catch (e, s) {
      LogUtil.v("未知異常出錯：$e\n$s");
      if (errorCallback != null) {
        errorCallback(HttpError(HttpError.UNKNOWN, "網絡異常，請稍後重試！"));
      }
    }
  }

  ///下載文件
  ///
  ///[url] 下載地址
  ///[savePath]  文件保存路徑
  ///[onReceiveProgress]  文件保存路徑
  ///[data] post 請求參數
  ///[params] url請求參數支持restful
  ///[options] 請求配置
  ///[successCallback] 請求成功回調
  ///[errorCallback] 請求失敗回調
  ///[tag] 請求統一標識，用於取消網絡請求
  void download({
    @required String url,
    @required savePath,
    ProgressCallback onReceiveProgress,
    Map<String, dynamic> params,
    data,
    Options options,
    HttpSuccessCallback successCallback,
    HttpFailureCallback errorCallback,
    @required String tag,
  }) async {
    //檢查網絡是否鏈接
    ConnectivityResult connectivityResult =
        await (Connectivity().checkConnectivity());
    if (connectivityResult == ConnectivityResult.none) {
      if (errorCallback != null) {
        errorCallback(HttpError(HttpError.NETWORK_ERROR, "網絡異常，請稍後重試！"));
      }
      LogUtil.v("請求網絡異常，請稍後重試！");
      return;
    }

    ////0表明不設置超時
    int receiveTimeout = 0;
    options ??= options == null
        ? Options(receiveTimeout: receiveTimeout)
        : options.merge(receiveTimeout: receiveTimeout);

    //設置默認值
    params = params ?? {};

    url = _restfulUrl(url, params);

    try {
      CancelToken cancelToken;
      if (tag != null) {
        cancelToken =
            _cancelTokens[tag] == null ? CancelToken() : _cancelTokens[tag];
        _cancelTokens[tag] = cancelToken;
      }

      Response response = await _client.download(url, savePath,
          onReceiveProgress: onReceiveProgress,
          queryParameters: params,
          data: data,
          options: options,
          cancelToken: cancelToken);
      //成功
      if (successCallback != null) {
        successCallback(response.data);
      }
    } on DioError catch (e, s) {
      LogUtil.v("請求出錯：$e\n$s");
      if (errorCallback != null && e.type != DioErrorType.CANCEL) {
        errorCallback(HttpError.dioError(e));
      }
    } catch (e, s) {
      LogUtil.v("未知異常出錯：$e\n$s");
      if (errorCallback != null) {
        errorCallback(HttpError(HttpError.UNKNOWN, "網絡異常，請稍後重試！"));
      }
    }
  }

  ///上傳文件
  ///
  ///[url] 網絡請求地址不包含域名
  ///[data] post 請求參數
  ///[onSendProgress] 上傳進度
  ///[params] url請求參數支持restful
  ///[options] 請求配置
  ///[successCallback] 請求成功回調
  ///[errorCallback] 請求失敗回調
  ///[tag] 請求統一標識，用於取消網絡請求
  void upload({
    @required String url,
    FormData data,
    ProgressCallback onSendProgress,
    Map<String, dynamic> params,
    Options options,
    HttpSuccessCallback successCallback,
    HttpFailureCallback errorCallback,
    @required String tag,
  }) async {
    //檢查網絡是否鏈接
    ConnectivityResult connectivityResult =
        await (Connectivity().checkConnectivity());
    if (connectivityResult == ConnectivityResult.none) {
      if (errorCallback != null) {
        errorCallback(HttpError(HttpError.NETWORK_ERROR, "網絡異常，請稍後重試！"));
      }
      LogUtil.v("請求網絡異常，請稍後重試！");
      return;
    }

    //設置默認值
    params = params ?? {};

    //強制 POST 請求
    options?.method = POST;

    options = options ??
        Options(
          method: POST,
        );

    url = _restfulUrl(url, params);

    try {
      CancelToken cancelToken;
      if (tag != null) {
        cancelToken =
            _cancelTokens[tag] == null ? CancelToken() : _cancelTokens[tag];
        _cancelTokens[tag] = cancelToken;
      }

      Response<Map<String, dynamic>> response = await _client.request(url,
          onSendProgress: onSendProgress,
          data: data,
          queryParameters: params,
          options: options,
          cancelToken: cancelToken);
      String statusCode = response.data["statusCode"];
      if (statusCode == "0") {
        //成功
        if (successCallback != null) {
          successCallback(response.data["data"]);
        }
      } else {
        //失敗
        String message = response.data["statusDesc"];
        LogUtil.v("請求服務器出錯：$message");
        if (errorCallback != null) {
          errorCallback(HttpError(statusCode, message));
        }
      }
    } on DioError catch (e, s) {
      LogUtil.v("請求出錯：$e\n$s");
      if (errorCallback != null && e.type != DioErrorType.CANCEL) {
        errorCallback(HttpError.dioError(e));
      }
    } catch (e, s) {
      LogUtil.v("未知異常出錯：$e\n$s");
      if (errorCallback != null) {
        errorCallback(HttpError(HttpError.UNKNOWN, "網絡異常，請稍後重試！"));
      }
    }
  }

  ///GET異步網絡請求
  ///
  ///[url] 網絡請求地址不包含域名
  ///[params] url請求參數支持restful
  ///[options] 請求配置
  ///[tag] 請求統一標識，用於取消網絡請求
  Future<T> getAsync<T>({
    @required String url,
    Map<String, dynamic> params,
    Options options,
    JsonParse<T> jsonParse,
    @required String tag,
  }) async {
    return _requestAsync(
      url: url,
      method: GET,
      params: params,
      options: options,
      jsonParse: jsonParse,
      tag: tag,
    );
  }

  ///POST 異步網絡請求
  ///
  ///[url] 網絡請求地址不包含域名
  ///[data] post 請求參數
  ///[params] url請求參數支持restful
  ///[options] 請求配置
  ///[tag] 請求統一標識，用於取消網絡請求
  Future<T> postAsync<T>({
    @required String url,
    data,
    Map<String, dynamic> params,
    Options options,
    JsonParse<T> jsonParse,
    @required String tag,
  }) async {
    return _requestAsync(
      url: url,
      method: POST,
      data: data,
      params: params,
      options: options,
      jsonParse: jsonParse,
      tag: tag,
    );
  }

  ///統一網絡請求
  ///
  ///[url] 網絡請求地址不包含域名
  ///[data] post 請求參數
  ///[params] url請求參數支持restful
  ///[options] 請求配置
  ///[tag] 請求統一標識，用於取消網絡請求
  Future<T> _requestAsync<T>({
    @required String url,
    String method,
    data,
    Map<String, dynamic> params,
    Options options,
    JsonParse<T> jsonParse,
    @required String tag,
  }) async {
    //檢查網絡是否鏈接
    ConnectivityResult connectivityResult =
        await (Connectivity().checkConnectivity());
    if (connectivityResult == ConnectivityResult.none) {
      LogUtil.v("請求網絡異常，請稍後重試！");
      throw (HttpError(HttpError.NETWORK_ERROR, "網絡異常，請稍後重試！"));
    }

    //設置默認值
    params = params ?? {};
    method = method ?? 'GET';

    options?.method = method;

    options = options ??
        Options(
          method: method,
        );

    url = _restfulUrl(url, params);

    try {
      CancelToken cancelToken;
      if (tag != null) {
        cancelToken =
            _cancelTokens[tag] == null ? CancelToken() : _cancelTokens[tag];
        _cancelTokens[tag] = cancelToken;
      }

      Response<Map<String, dynamic>> response = await _client.request(url,
          queryParameters: params,
          data: data,
          options: options,
          cancelToken: cancelToken);
      String statusCode = response.data["statusCode"];
      if (statusCode == "0") {
        //成功
        if (jsonParse != null) {
          return jsonParse(response.data["data"]);
        } else {
          return response.data["data"];
        }
      } else {
        //失敗
        String message = response.data["statusDesc"];
        LogUtil.v("請求服務器出錯：$message");
        //只能用 Future，外層有 try catch
        return Future.error((HttpError(statusCode, message)));
      }
    } on DioError catch (e, s) {
      LogUtil.v("請求出錯：$e\n$s");
      throw (HttpError.dioError(e));
    } catch (e, s) {
      LogUtil.v("未知異常出錯：$e\n$s");
      throw (HttpError(HttpError.UNKNOWN, "網絡異常，請稍後重試！"));
    }
  }

  ///異步下載文件
  ///
  ///[url] 下載地址
  ///[savePath]  文件保存路徑
  ///[onReceiveProgress]  文件保存路徑
  ///[data] post 請求參數
  ///[params] url請求參數支持restful
  ///[options] 請求配置
  ///[tag] 請求統一標識，用於取消網絡請求
  Future<Response> downloadAsync({
    @required String url,
    @required savePath,
    ProgressCallback onReceiveProgress,
    Map<String, dynamic> params,
    data,
    Options options,
    @required String tag,
  }) async {
    //檢查網絡是否鏈接
    ConnectivityResult connectivityResult =
        await (Connectivity().checkConnectivity());
    if (connectivityResult == ConnectivityResult.none) {
      LogUtil.v("請求網絡異常，請稍後重試！");
      throw (HttpError(HttpError.NETWORK_ERROR, "網絡異常，請稍後重試！"));
    }
    //設置下載不超時
    int receiveTimeout = 0;
    options ??= options == null
        ? Options(receiveTimeout: receiveTimeout)
        : options.merge(receiveTimeout: receiveTimeout);

    //設置默認值
    params = params ?? {};

    url = _restfulUrl(url, params);

    try {
      CancelToken cancelToken;
      if (tag != null) {
        cancelToken =
            _cancelTokens[tag] == null ? CancelToken() : _cancelTokens[tag];
        _cancelTokens[tag] = cancelToken;
      }

      return _client.download(url, savePath,
          onReceiveProgress: onReceiveProgress,
          queryParameters: params,
          data: data,
          options: options,
          cancelToken: cancelToken);
    } on DioError catch (e, s) {
      LogUtil.v("請求出錯：$e\n$s");
      throw (HttpError.dioError(e));
    } catch (e, s) {
      LogUtil.v("未知異常出錯：$e\n$s");
      throw (HttpError(HttpError.UNKNOWN, "網絡異常，請稍後重試！"));
    }
  }

  ///上傳文件
  ///
  ///[url] 網絡請求地址不包含域名
  ///[data] post 請求參數
  ///[onSendProgress] 上傳進度
  ///[params] url請求參數支持restful
  ///[options] 請求配置
  ///[tag] 請求統一標識，用於取消網絡請求
  Future<T> uploadAsync<T>({
    @required String url,
    FormData data,
    ProgressCallback onSendProgress,
    Map<String, dynamic> params,
    Options options,
    JsonParse<T> jsonParse,
    @required String tag,
  }) async {
    //檢查網絡是否鏈接
    ConnectivityResult connectivityResult =
        await (Connectivity().checkConnectivity());
    if (connectivityResult == ConnectivityResult.none) {
      LogUtil.v("請求網絡異常，請稍後重試！");
      throw (HttpError(HttpError.NETWORK_ERROR, "網絡異常，請稍後重試！"));
    }

    //設置默認值
    params = params ?? {};

    //強制 POST 請求
    options?.method = POST;

    options = options ??
        Options(
          method: POST,
        );

    url = _restfulUrl(url, params);

    try {
      CancelToken cancelToken;
      if (tag != null) {
        cancelToken =
            _cancelTokens[tag] == null ? CancelToken() : _cancelTokens[tag];
        _cancelTokens[tag] = cancelToken;
      }

      Response<Map<String, dynamic>> response = await _client.request(url,
          onSendProgress: onSendProgress,
          data: data,
          queryParameters: params,
          options: options,
          cancelToken: cancelToken);

      String statusCode = response.data["statusCode"];
      if (statusCode == "0") {
        //成功
        if (jsonParse != null) {
          return jsonParse(response.data["data"]);
        } else {
          return response.data["data"];
        }
      } else {
        //失敗
        String message = response.data["statusDesc"];
        LogUtil.v("請求服務器出錯：$message");
        return Future.error((HttpError(statusCode, message)));
      }
    } on DioError catch (e, s) {
      LogUtil.v("請求出錯：$e\n$s");
      throw (HttpError.dioError(e));
    } catch (e, s) {
      LogUtil.v("未知異常出錯：$e\n$s");
      throw (HttpError(HttpError.UNKNOWN, "網絡異常，請稍後重試！"));
    }
  }

  ///取消網絡請求
  void cancel(String tag) {
    if (_cancelTokens.containsKey(tag)) {
      if (!_cancelTokens[tag].isCancelled) {
        _cancelTokens[tag].cancel();
      }
      _cancelTokens.remove(tag);
    }
  }

  ///restful處理
  String _restfulUrl(String url, Map<String, dynamic> params) {
    // restful 請求處理
    // /gysw/search/hist/:user_id        user_id=27
    // 最終生成 url 爲     /gysw/search/hist/27
    params.forEach((key, value) {
      if (url.indexOf(key) != -1) {
        url = url.replaceAll(':$key', value.toString());
      }
    });
    return url;
  }
}

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這裏處理了網絡鏈接判斷、取消網絡請求、默認的數據格式解析等。默認解析的數據格式：

{
	"data":{},
	"statusCode":"0",
	"statusDesc":"02032008:用戶授信未經過",
	"timestamp":1569206576392
}
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你們可根據本身的需求更改爲本身的數據格式處理

HttpError

import 'package:dio/dio.dart';

/// @desc  網絡請求錯誤
/// @time 2019/3/20 10:02 AM
/// @author Cheney
class HttpError {
  ///HTTP 狀態碼
  static const int UNAUTHORIZED = 401;
  static const int FORBIDDEN = 403;
  static const int NOT_FOUND = 404;
  static const int REQUEST_TIMEOUT = 408;
  static const int INTERNAL_SERVER_ERROR = 500;
  static const int BAD_GATEWAY = 502;
  static const int SERVICE_UNAVAILABLE = 503;
  static const int GATEWAY_TIMEOUT = 504;

  ///未知錯誤
  static const String UNKNOWN = "UNKNOWN";

  ///解析錯誤
  static const String PARSE_ERROR = "PARSE_ERROR";

  ///網絡錯誤
  static const String NETWORK_ERROR = "NETWORK_ERROR";

  ///協議錯誤
  static const String HTTP_ERROR = "HTTP_ERROR";

  ///證書錯誤
  static const String SSL_ERROR = "SSL_ERROR";

  ///鏈接超時
  static const String CONNECT_TIMEOUT = "CONNECT_TIMEOUT";

  ///響應超時
  static const String RECEIVE_TIMEOUT = "RECEIVE_TIMEOUT";

  ///發送超時
  static const String SEND_TIMEOUT = "SEND_TIMEOUT";

  ///網絡請求取消
  static const String CANCEL = "CANCEL";

  String code;

  String message;

  HttpError(this.code, this.message);

  HttpError.dioError(DioError error) {
    message = error.message;
    switch (error.type) {
      case DioErrorType.CONNECT_TIMEOUT:
        code = CONNECT_TIMEOUT;
        message = "網絡鏈接超時，請檢查網絡設置";
        break;
      case DioErrorType.RECEIVE_TIMEOUT:
        code = RECEIVE_TIMEOUT;
        message = "服務器異常，請稍後重試！";
        break;
      case DioErrorType.SEND_TIMEOUT:
        code = SEND_TIMEOUT;
        message = "網絡鏈接超時，請檢查網絡設置";
        break;
      case DioErrorType.RESPONSE:
        code = HTTP_ERROR;
        message = "服務器異常，請稍後重試！";
        break;
      case DioErrorType.CANCEL:
        code = CANCEL;
        message = "請求已被取消，請從新請求";
        break;
      case DioErrorType.DEFAULT:
        code = UNKNOWN;
        message = "網絡異常，請稍後重試！";
        break;
    }
  }

  @override
  String toString() {
    return 'HttpError{code: $code, message: $message}';
  }
}

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這裏設置了多種錯誤的描述，你們可根據需求修改。

LogInterceptor

import 'package:dio/dio.dart';
import 'package:flutter_common_utils/log_util.dart';

void log2Console(Object object) {
  LogUtil.v(object);
}

/// @desc  自定義日誌攔截器
///@time 2019/3/18 9:15 AM
/// @author Cheney
class LogInterceptor extends Interceptor {
  LogInterceptor({
    this.request = true,
    this.requestHeader = true,
    this.requestBody = false,
    this.responseHeader = true,
    this.responseBody = false,
    this.error = true,
    this.logPrint = log2Console,
  });

  /// Print request [Options]
  bool request;

  /// Print request header [Options.headers]
  bool requestHeader;

  /// Print request data [Options.data]
  bool requestBody;

  /// Print [Response.data]
  bool responseBody;

  /// Print [Response.headers]
  bool responseHeader;

  /// Print error message
  bool error;

  /// Log printer; defaults print log to console.
  /// In flutter, you'd better use debugPrint. /// you can also write log in a file, for example: ///```dart /// var file=File("./log.txt"); /// var sink=file.openWrite(); /// dio.interceptors.add(LogInterceptor(logPrint: sink.writeln)); /// ... /// await sink.close(); ///``` void Function(Object object) logPrint; @override Future onRequest(RequestOptions options) async { logPrint('*** Request ***'); printKV('uri', options.uri); if (request) { printKV('method', options.method); printKV('responseType', options.responseType?.toString()); printKV('followRedirects', options.followRedirects); printKV('connectTimeout', options.connectTimeout); printKV('receiveTimeout', options.receiveTimeout); printKV('extra', options.extra); } if (requestHeader) { logPrint('headers:'); options.headers.forEach((key, v) => printKV(" $key", v)); } if (requestBody) { logPrint("data:"); printAll(options.data); } logPrint(""); } @override Future onError(DioError err) async { if (error) { logPrint('*** DioError ***:'); logPrint("uri: ${err.request.uri}"); logPrint("$err"); if (err.response != null) { _printResponse(err.response); } logPrint(""); } } @override Future onResponse(Response response) async { logPrint("*** Response ***"); _printResponse(response); } void _printResponse(Response response) { printKV('uri', response.request?.uri); if (responseHeader) { printKV('statusCode', response.statusCode); if (response.isRedirect == true) { printKV('redirect', response.realUri); } if (response.headers != null) { logPrint("headers:"); response.headers.forEach((key, v) => printKV(" $key", v.join(","))); } } if (responseBody) { logPrint("Response Text:"); printAll(response.toString()); } logPrint(""); } printKV(String key, Object v) { logPrint('$key: $v'); } printAll(msg) { msg.toString().split("\n").forEach(logPrint); } } 複製代碼

這裏默認使用 LogUtl 輸出日誌，你們可根據須要換成本身的日誌輸出工具類

使用示例

Step1：初始化

//初始化 Http，
  HttpManager().init(
    baseUrl: Api.getBaseUrl(),
    interceptors: [
      HeaderInterceptor(),
      LogInterceptor(),
    ],
  );
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Step2：建立網絡請求

///同步回調模式
///get 網絡請求
void _get(){
   HttpManager().get(
      url: "/app/info",
      params: {"iouCode": iouCode},
      successCallback: (data) {
        
      },
      errorCallback: (HttpError error) {
       
      },
      tag: "tag",
    );
}
///post 網絡請求
void _post(){
     HttpManager().post(
      url: "/app/info",
      data: {"iouCode": iouCode},
      successCallback: (data) {
        
      },
      errorCallback: (HttpError error) {
        
      },
      tag: "tag",
    );
}

///下載文件
void _download(){
     HttpManager().download(
      url: "/app/download",
      savePath: "/savePath",
      onReceiveProgress: (int count, int total) {
      },
      successCallback: (data) {
        
      },
      errorCallback: (HttpError error) {
        
      },
      tag: tag,
    );
}

///上傳文件
void _upload() async{
FormData data = FormData.fromMap({
        "file": await MultipartFile.fromFile(path, filename: "$photoTime"),
      });
    HttpManager().upload(
        url: "/app/upload",
        data: data,
        tag: "tag",
        successCallback: (data) {
          
        },
        errorCallback: (HttpError error) {
          
        },
      );
}


///異步模式
///get 請求
void _getAysnc() async{
     String timestamp =
        await HttpManager().getAsync(url: "/app/info", tag: "syncTime");
}

///post 請求
void _postAysnc() async{
   await HttpManager().postAsync(
        url: "app/info",
        tag: "tag",
        data: {
          'bannerTypes': ["wealthBanner"],
        },
        jsonParse: (json) => Pager(json, (data) => ImageAd(data)))
}

///下載文件
void _downloadAsync() async{
    await HttpManager().downloadAsync(
      url: "/app/download",
      savePath: "/savePath",
      onReceiveProgress: (int count, int total) {
      },
      tag: "tag",
    );
}

///上傳文件
void _uploadAsync() async{
FormData data = FormData.fromMap({
        "file": await MultipartFile.fromFile(path, filename: "$photoTime"),
      });
  await  HttpManager().uploadAsync(
        url: "/app/upload",
        data: data,
        tag: "tag",
       
      );
}
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