Flutter+retrofit +dio+rxdart网络请求

pubspec.yaml:

dependencies:
rxdart: ^0.23.1
retrofit: '>=3.0.0 <4.0.0'
logger: any #for logging purpose

dev_dependencies:
retrofit_generator: any
build_runner: '>1.3.0 <4.0.0'//用于生成.g文件
json_serializable: '>4.4.0'//生成实体

json_serializable代码在线生成网址
运行:flutter packages pub run build_runner build 会生成 .g文件
报错 flutter packages get
part 'RestClient.g.dart'; //必须配置，否则无法生成.g文件

BaseError

abstract class BaseError {
  final int? code;
  final String? message;

  BaseError({this.code, this.message});
}

class NeedLogin implements BaseError {
  @override
  int get code => 401;

  @override
  String get message => "请先登录";
}

class NeedAuth implements BaseError {
  @override
  int get code => 403;

  @override
  String get message => "非法访问，请使用正确的token";
}

class UserNotExist implements BaseError {
  @override
  int get code => 408;

  @override
  String get message => "用户不存在";
}

class UserNameEmpty implements BaseError {
  @override
  int get code => 405;

  @override
  String get message => "用户名不能为空";
}

class PwdNotMatch implements BaseError {
  @override
  int get code => 409;

  @override
  String get message => "用户密码不正确";
}

class PwdEmpty implements BaseError {
  @override
  int get code => 406;

  @override
  String get message => "用户密码不能为空";
}

class OtherError implements BaseError {
  final int? statusCode;
  final String? statusMessage;

  OtherError({this.statusCode, this.statusMessage});

  @override
  int? get code => statusCode;

  @override
  String? get message => statusMessage;
}

HeaderInterceptor

///    author : luzi
///    date   : 2021/7/11
///    desc   : 请求头拦截器
class HeaderInterceptor extends Interceptor {
  @override
  Future<void> onRequest(
    RequestOptions options,
    RequestInterceptorHandler handler,
  ) async {
    Map<String, dynamic> headers = options.headers;
    headers['clientId'] = 1; //渠道(1.APP 2.Web）
    if (Platform.isAndroid) {
      headers['systemName'] = 'Android'; //系统名称
    } else if (Platform.isIOS) {
      headers['systemName'] = 'iOS'; //系统名称
    }

    var time = DateTime.now().millisecondsSinceEpoch;
    headers['ts'] = time; //时间戳
    String sign = getParamsStr(options, time);
    headers['sign'] = sign; //参数加密签名
    headers['language'] = Get.locale?.countryCode ?? 'MY'; //语言环境
    headers['Accept'] = 'application/json';
    options.headers = headers;
    handler.next(options);
  }

  getParamsStr(RequestOptions options, int time) {
    StringBuffer stringBuffer = new StringBuffer();
    String? paramsStr;
    var method = options.method;
    if (method == 'GET') {
      if (options.queryParameters.isNotEmpty) {
        String query = options.uri.query;
        var splitArray = query.split('&');
        var splayTreeMap = new SplayTreeMap();
        splitArray.forEach((split) {
          var splitChild = split.split('=');
          splayTreeMap[splitChild[0]] = Uri.encodeQueryComponent(splitChild[1]);
        });
        paramsStr = json.encode(splayTreeMap);
        if (paramsStr.isNotEmpty) {
          stringBuffer.write('$paramsStr&');
        } else {
          stringBuffer.write('{}&');
        }
      } else {
        stringBuffer.write('{}&');
      }
    } else if (method == 'POST') {
      var data = options.data;
      if (data is FormData) {
        if (data.fields.isNotEmpty) {
          String replace = data.fields
              .join(",")
              .replaceAll('MapEntry', '')
              .replaceAll('(', '')
              .replaceAll(')', '');
          paramsStr = replace;
          if (paramsStr.isNotEmpty) {
            stringBuffer.write('{$paramsStr}&');
          } else {
            stringBuffer.write('{}&');
          }
        } else {
          stringBuffer.write('{}&');
        }
      } else {
        paramsStr = jsonEncode(data);
        if (paramsStr.isNotEmpty) {
          stringBuffer.write('$paramsStr&');
        } else {
          stringBuffer.write('{}&');
        }
      }
    }
    // NativeUtils.sendNativeData(NativeUtils.NATIVE_LOG, paramsStr.toString());
    // print(paramsStr.toString());
    stringBuffer.write('ts=$time&');
    stringBuffer.write('tmpsign=${DioManager.getInstance().signKey}');
    String toString = stringBuffer.toString().replaceAll("\"", "");
    // NativeUtils.sendNativeData(NativeUtils.NATIVE_LOG, toString);
    // print(toString);
    // Get.log.printInfo(info: '拼接后：$toString');
    var content = new Utf8Encoder().convert(toString);
    var digest = md5.convert(content);
    String md5Encode = hex.encode(digest.bytes).toUpperCase();
    Get.log.printInfo(info: 'MD5：$md5Encode');
    return md5Encode;
  }
}

BaseDio

class BaseDio {
  BaseDio._(); // 把构造方法私有化

  static BaseDio? _instance;

  static BaseDio? getInstance() {  // 通过 getInstance 获取实例
    _instance ??= BaseDio._();

    return _instance;
  }

  Dio getDio() {
    final Dio dio = Dio();
    dio.options = BaseOptions(receiveTimeout: 55000, connectTimeout: 66000); // 设置超时时间等 ...
    dio.interceptors.add(HeaderInterceptor()); // 添加拦截器，如 token之类，需要全局使用的参数
    dio.interceptors.add(PrettyDioLogger(  // 添加日志格式化工具类
      requestHeader: true,
      requestBody: true,
      responseBody: true,
      responseHeader: false,
      compact: false,
    ));

    return dio;
  }

  BaseError getDioError(Object obj) {  // 这里封装了一个 BaseError 类，会根据后端返回的code返回不同的错误类
    switch (obj.runtimeType) {
      case DioError:
         if ((obj as DioError).type == DioErrorType.response) {
          final response = (obj as DioError).response;
          if (response!.statusCode == 401) {
            return NeedLogin();
          } else if (response!.statusCode == 403) {
            return NeedAuth();
          } else if (response.statusCode == 408) {
            return UserNotExist();
          } else if (response.statusCode == 409) {
            return PwdNotMatch();
          } else if (response.statusCode == 405) {
            return UserNameEmpty();
          } else if (response.statusCode == 406) {
            return PwdEmpty();
          } else {
            return OtherError(
              statusCode: response.statusCode,
              statusMessage: response.statusMessage,
            );
          }
        }
    }

    return OtherError();
  }
}

RestApi

part 'RestClient.g.dart'; //必须配置，否则无法生成.g文件

@RestApi(baseUrl: "https://uat.../")
abstract class RestClient {
  factory RestClient({Dio? dio, String? baseUrl}) {
    dio ??= BaseDio.getInstance()!.getDio();
    return _RestClient(dio, baseUrl: baseUrl);
  }

  @POST("user/getImgCode.do")
  // Future<Task> getTasks(@Body()Task task);
  Future<Entity> getTasks(@Body() loginparms task);
}

//
// @JsonSerializable()
// class Task {
//   String? imgToken;
//   String? img;
//
//   Task({this.imgToken, this.img});
//
//   factory Task.fromJson(Map<String, dynamic> json) => _$TaskFromJson(json);
//   Map<String, dynamic> toJson() => _$TaskToJson(this);
// }
@JsonSerializable()
class Entity extends Object {
  @JsonKey(name: 'data')
  Data data;

  Entity(
    this.data,
  );

  factory Entity.fromJson(Map<String, dynamic> srcJson) =>
      _$EntityFromJson(srcJson);

  Map<String, dynamic> toJson() => _$EntityToJson(this);
}

@JsonSerializable()
class Data extends Object {
  @JsonKey(name: 'imgToken')
  String imgToken;

  @JsonKey(name: 'img')
  String img;

  Data(
    this.imgToken,
    this.img,
  );

  factory Data.fromJson(Map<String, dynamic> srcJson) =>
      _$DataFromJson(srcJson);

  Map<String, dynamic> toJson() => _$DataToJson(this);
}

@JsonSerializable()
class loginparms extends Object {

  @JsonKey(name: 'parameter')
  Parameter parameter;

  @JsonKey(name: 'versionCode')
  String versionCode;

  loginparms(this.parameter,this.versionCode,);

  factory loginparms.fromJson(Map<String, dynamic> srcJson) => _$loginparmsFromJson(srcJson);

  Map<String, dynamic> toJson() => _$loginparmsToJson(this);

}


@JsonSerializable()
class Parameter extends Object {

  Parameter();

  factory Parameter.fromJson(Map<String, dynamic> srcJson) => _$ParameterFromJson(srcJson);

  Map<String, dynamic> toJson() => _$ParameterToJson(this);

调用

Future<void> clickLike() async {
    try {
      print('你好============123456789--0}');
  
      Parameter parameter=Parameter();
      loginparms loginparm= loginparms(parameter,"");
      Entity data = await RestClient().getTasks(loginparm); // 使用非常简单一句代码即可
      // ImageCodeBean data = await RestClient().getTasks(map); // 使用非常简单一句代码即可
      print('你好============123456789--5${data.data.imgToken}');
    } catch (e) {
      error: BaseDio.getInstance()!.getDioError(e);
      //拿到BaseError对应自定义message错误信息
      print('你好============123456789--1${BaseDio.getInstance()!.getDioError(e).message}');

    }
  }

可参照:https://www.psvmc.cn/article/2020-05-12-flutter-start-07-http-json.html