flutter 专题 六十六 Flutter Dio包网络请求抓包解决方案

在Flutter中进行网络请求时，我们可以使用的库有3个，即Http请求库、HttpClient请求库和Dio请求库（详细介绍请参考：Flutter开发之Http网络请求），使用得最多的就是Dio请求库。因为相比Http请求库和HttpClient请求库，Dio库不仅支持常见的网络请求，还支持Restful API、FormData、拦截器、请求取消、Cookie管理、文件上传/下载、超时等操作。

不过，默认情况下，Dio进行网络请求时是不支持抓包的，所以如果要进行抓包，就需要对Dio进行请求封装，并编写代理代码。下面是代理的几种写法：

方法一

我们可以直接在Dio里面设置ip以及端口，通过硬编码的方式进行代理，代码如下：

(_dio.httpClientAdapter as DefaultHttpClientAdapter).onHttpClientCreate =(client) {//这一段是解决安卓https抓包的问题client.badCertificateCallback =(X509Certificate cert, String host, int port) {return Platform.isAndroid;};client.findProxy = (uri) {return "PROXY 代理ip:代理port";};};

不过，这种硬编码方式，写得太死，不够灵活，每次更改代理都需要打包。

方法二

直接在原生插件获取手代理ip和代理端口，不过Android比较难，下面是iOS的实现。

 //自动获取手机代理NSDictionary *proxySettings = (__bridge NSDictionary *)(CFNetworkCopySystemProxySettings());NSArray *proxies = (__bridge NSArray *)(CFNetworkCopyProxiesForURL((__bridge CFURLRef _Nonnull)([NSURL URLWithString:call.arguments]), (__bridge CFDictionaryRef _Nonnull)(proxySettings)));NSString *hostName = proxySettings[@"HTTPSProxy"];NSString *portName = [NSString stringWithFormat:@"%@",proxySettings[@"HTTPPort"]];long HTTPEnable = [proxySettings[@"HTTPEnable"] longValue];if (HTTPEnable==0) {hostName = @"";}

方法三

除了上面的硬编码方式外，我们还可以采用scheme协议的方式传入代理ip和代理端口。此方法的步骤如下：
1，注册自己的URL Scheme，例如：scheme://
2，定义参数规则，例如：scheme://tiaoshi?host=10.0.206.163
3，引入flutter插件：uni_links: ^0.2.0
4，flutter监听解析参数，并在dio里面设置代理
5，使用[草料]https://cli.im生成一个二维码：内容：scheme://tiaoshi?host=10.0.206.163
6，使用原生相机扫码进入app就可以抓包

下面是涉及的代码，Flutter代码如下：

Future<Null> initUniLinks() async {// 监听插件scheme数据getLinksStream().listen((String link) {link =  Uri.decodeComponent(link);if(link.contains("scheme://")){String type = getTypeStr(link);String param = link.replaceAll("scheme://$type?", "");Map dict = getUrlParams(param);if(type=="tiaoshi"){//设置抓包代理String host = dict["host"];String port = dict["port"];//这里是网络请求封装Net.setHttpProxy(host,port==null?"8888":port);}}// Parse the link and warn the user, if it is not correct}, onError: (err) {// Handle exception by warning the user their action did not succeed});}//获取scheme 要处理的业务类型String getTypeStr(String link){List params = link.split("?");String typeStr = params[0];typeStr =  typeStr.replaceAll("scheme://", "");return typeStr;}//url参数转mapMap getUrlParams(String paramStr) {Map map = Map();List params = paramStr.split("&");for(int i=0;i<params.length;i++){String str = params[i];List arr = str.split("=");map[arr[0]]= arr[1];}return map;}

代理层代码：

static void setHttpProxy(String host,String port) {Application.httpProxy = host+':'+port;_initDio();}static Future<void> _initDio() async {DeviceInfoPlugin deviceInfo = DeviceInfoPlugin();if (Platform.isAndroid) {_androidInfo = await deviceInfo.androidInfo;} else if (Platform.isIOS) {_iosInfo = await deviceInfo.iosInfo;}_dio = Dio(BaseOptions(contentType: 'application/json',baseUrl: Config.BASE_URL,));_dio.options.receiveTimeout = 5000;_dio.options.connectTimeout = 10000;if (Application.httpProxy.length != 0) {(_dio.httpClientAdapter as DefaultHttpClientAdapter).onHttpClientCreate =(client) {//这一段是解决安卓https抓包的问题client.badCertificateCallback =(X509Certificate cert, String host, int port) {return Platform.isAndroid;};//这是抓包代理client.findProxy = (uri) {return "PROXY ${Application.httpProxy}";};};}_dio.interceptors.addAll([InterceptorsWrapper(onRequest: (Options options) {options.headers['DeviceName'] = 'xxxx';return options;},onResponse: (Response res) {try {...return res;} catch (e) {return res;}},onError: (DioError e) {print(e);}break;default:}return e;},),]);}static Future<ResponseModel> get(String path, {Map<String, dynamic> queryParameters,Options options,CancelToken cancelToken,void Function(int, int) onReceiveProgress,}) async {if (_dio == null) {await _initDio();}final res = await _dio.get<ResponseModel>(path,queryParameters: queryParameters,options: options,cancelToken: cancelToken,onReceiveProgress: onReceiveProgress,);return res.data;}static Future<ResponseModel> post(String path, {dynamic data,Map<String, dynamic> queryParameters,Options options,CancelToken cancelToken,void Function(int, int) onSendProgress,void Function(int, int) onReceiveProgress,}) async {if (_dio == null) {await _initDio();}final res = await _dio.post<ResponseModel>(path,data: data,queryParameters: queryParameters,options: options,cancelToken: cancelToken,onSendProgress: onSendProgress,onReceiveProgress: onReceiveProgress,);return res.data;}