Flutter Dio二次封装的实现

时间:2022-07-27
本文章向大家介绍Flutter Dio二次封装的实现,主要内容包括其使用实例、应用技巧、基本知识点总结和需要注意事项,具有一定的参考价值,需要的朋友可以参考一下。

目录:

  • DioManager:Dio辅助类NWMethod:请求方法,get、post等
  • NWApi:大家都知道
  • EntityFactory:json转换辅助工厂,把json转为T
  • BaseEntity<T :数据基类,返回的参数为 {“code”: 0, “message”: “”, “data”: {}}
  • BaseListEntity<T :数据基类2,返回的参数为 {“code”: 0, “message”: “”, “data”: []}
  • ErrorEntity:请求报错基类,{“code”: 0, “message”: “”}

EntityFactory:

class EntityFactory {
 static T generateOBJ<T (json) {
  if (json == null) {
   return null;
  }
//可以在这里加入任何需要并且可以转换的类型,例如下面
//  else if (T.toString() == "LoginEntity") {
//   return LoginEntity.fromJson(json) as T;
//  }
  else {
   return json as T;
  }
 }
}

BaseEntity:

class BaseEntity<T  {
 int code;
 String message;
 T data;

 BaseEntity({this.code, this.message, this.data});

 factory BaseEntity.fromJson(json) {
  return BaseEntity(
   code: json["code"],
   message: json["msg"],
   // data值需要经过工厂转换为我们传进来的类型
   data: EntityFactory.generateOBJ<T (json["data"]),
  );
 }
}

BaseListEntity:

class BaseListEntity<T  {
 int code;
 String message;
 List<T  data;

 BaseListEntity({this.code, this.message, this.data});

 factory BaseListEntity.fromJson(json) {
  List<T  mData = List();
  if (json['data'] != null) {
   //遍历data并转换为我们传进来的类型
   (json['data'] as List).forEach((v) {
    mData.add(EntityFactory.generateOBJ<T (v));
   });
  }

  return BaseListEntity(
   code: json["code"],
   message: json["msg"],
   data: mData,
  );
 } }

ErrorEntity:

class ErrorEntity {
 int code;
 String message;
 ErrorEntity({this.code, this.message});
}

NWApi:

class NWApi {
 static final baseApi = "https://easy-mock.bookset.io/mock/5dfae67d4946c20a50841fa7/example/";
 static final loginPath = "user/login";//接口返回:{"code": int, "message": "String", "data": {"account": "String", "password": "String"}}
 static final queryListPath = "/query/list";//接口返回:{"code": ing, "message": "String", "data": [int, int, String, int, String, int]}
 static final queryListJsonPath = "/query/listjson";//接口返回:{"code": int, "message": "String", "data": [{"account": "String", "password": "String"}, {"account": "String", "password": "String"}]}
}

NWMethod:

enum NWMethod {
 GET,
 POST,
 DELETE,
 PUT
}
//使用:NWMethodValues[NWMethod.POST]
const NWMethodValues = {
 NWMethod.GET: "get",
 NWMethod.POST: "post",
 NWMethod.DELETE: "delete",
 NWMethod.PUT: "put"
};

下面就可以进行正式的封装了:

第一步是创建Dio的单例辅助类,并初始化Dio和对Dio进行一些全局的参数设置:

import 'package:dio/dio.dart';
import 'package:flutter_app/network/NWApi.dart';
import 'package:flutter_app/utils/PrintUtil.dart';
class DioManager {
 static final DioManager _shared = DioManager._internal();
 factory DioManager() =  _shared;
 Dio dio;
 DioManager._internal() {
  if (dio == null) {
   BaseOptions options = BaseOptions(
    baseUrl: NWApi.baseApi,
    contentType: Headers.jsonContentType,
    responseType: ResponseType.json,
    receiveDataWhenStatusError: false,
    connectTimeout: 30000,
    receiveTimeout: 3000,
   );
   dio = Dio(options);
  }
 }
}

第二步对请求进行封装,在我的想法中 {“code”: 0, “message”: “”, “data”: {}} 和 {“code”: 0, “message”: “”, “data”: []} 这两种数据是要分开两个请求方法的:

 // 请求,返回参数为 T
 // method:请求方法,NWMethod.POST等
 // path:请求地址
 // params:请求参数
 // success:请求成功回调
 // error:请求失败回调
 Future request<T (NWMethod method, String path, {Map params, Function(T) success, Function(ErrorEntity) error}) async {
  try {
   Response response = await dio.request(path, queryParameters: params, options: Options(method: NWMethodValues[method]));
   if (response != null) {
    BaseEntity entity = BaseEntity<T .fromJson(response.data);
    if (entity.code == 0) {
     success(entity.data);
    } else {
     error(ErrorEntity(code: entity.code, message: entity.message));
    }
   } else {
    error(ErrorEntity(code: -1, message: "未知错误"));
   }
  } on DioError catch(e) {
   error(createErrorEntity(e));
  }
 }

 // 请求,返回参数为 List
 // method:请求方法,NWMethod.POST等
 // path:请求地址
 // params:请求参数
 // success:请求成功回调
 // error:请求失败回调
 Future requestList<T (NWMethod method, String path, {Map params, Function(List) success, Function(ErrorEntity) error}) async {
  try {
   Response response = await dio.request(path, queryParameters: params, options: Options(method: NWMethodValues[method]));
   if (response != null) {
    BaseListEntity entity = BaseListEntity<T .fromJson(response.data);
    if (entity.code == 0) {
     success(entity.data);
    } else {
     error(ErrorEntity(code: entity.code, message: entity.message));
    }
   } else {
     error(ErrorEntity(code: -1, message: "未知错误"));
   }
  } on DioError catch(e) {
   error(createErrorEntity(e));
  }
 }

提取请求错误处理方法createErrorEntity:

 // 错误信息
 ErrorEntity createErrorEntity(DioError error) {
  switch (error.type) {
   case DioErrorType.CANCEL:{
    return ErrorEntity(code: -1, message: "请求取消");
   }
   break;
   case DioErrorType.CONNECT_TIMEOUT:{
    return ErrorEntity(code: -1, message: "连接超时");
   }
   break;
   case DioErrorType.SEND_TIMEOUT:{
    return ErrorEntity(code: -1, message: "请求超时");
   }
   break;
   case DioErrorType.RECEIVE_TIMEOUT:{
    return ErrorEntity(code: -1, message: "响应超时");
   }
   break;
   case DioErrorType.RESPONSE:{
    try {
     int errCode = error.response.statusCode;
     String errMsg = error.response.statusMessage;
     return ErrorEntity(code: errCode, message: errMsg);
//     switch (errCode) {
//      case 400: {
//       return ErrorEntity(code: errCode, message: "请求语法错误");
//      }
//      break;
//      case 403: {
//       return ErrorEntity(code: errCode, message: "服务器拒绝执行");
//      }
//      break;
//      case 404: {
//       return ErrorEntity(code: errCode, message: "无法连接服务器");
//      }
//      break;
//      case 405: {
//       return ErrorEntity(code: errCode, message: "请求方法被禁止");
//      }
//      break;
//      case 500: {
//       return ErrorEntity(code: errCode, message: "服务器内部错误");
//      }
//      break;
//      case 502: {
//       return ErrorEntity(code: errCode, message: "无效的请求");
//      }
//      break;
//      case 503: {
//       return ErrorEntity(code: errCode, message: "服务器挂了");
//      }
//      break;
//      case 505: {
//       return ErrorEntity(code: errCode, message: "不支持HTTP协议请求");
//      }
//      break;
//      default: {
//       return ErrorEntity(code: errCode, message: "未知错误");
//      }
//     }
    } on Exception catch(_) {
     return ErrorEntity(code: -1, message: "未知错误");
    }
   }
   break;
   default: {
    return ErrorEntity(code: -1, message: error.message);
   }
  }
 }

完整的 DioManager 类代码:

import 'package:dio/dio.dart';
import 'package:flutter_app/network/entity/BaseEntity.dart';
import 'package:flutter_app/network/entity/BaseListEntity.dart';
import 'package:flutter_app/network/entity/EntityFactory.dart';
import 'package:flutter_app/network/entity/ErrorEntity.dart';
import 'package:flutter_app/network/NWApi.dart';
import 'package:flutter_app/network/NWMethod.dart';
class DioManager {
static final DioManager _shared = DioManager._internal();
factory DioManager() =  _shared;
Dio dio;
DioManager._internal() {
if (dio == null) {
BaseOptions options = BaseOptions(
baseUrl: NWApi.baseApi,
contentType: Headers.jsonContentType,
responseType: ResponseType.json,
receiveDataWhenStatusError: false,
connectTimeout: 30000,
receiveTimeout: 3000,
);
dio = Dio(options);
}
}
// 请求,返回参数为 T
// method:请求方法,NWMethod.POST等
// path:请求地址
// params:请求参数
// success:请求成功回调
// error:请求失败回调
Future request<T (NWMethod method, String path, {Map params, Function(T) success, Function(ErrorEntity) error}) async {
try {
Response response = await dio.request(path, queryParameters: params, options: Options(method: NWMethodValues[method]));
if (response != null) {
BaseEntity entity = BaseEntity<T .fromJson(response.data);
if (entity.code == 0) {
success(entity.data);
} else {
error(ErrorEntity(code: entity.code, message: entity.message));
}
} else {
error(ErrorEntity(code: -1, message: "未知错误"));
}
} on DioError catch(e) {
error(createErrorEntity(e));
}
}
// 请求,返回参数为 List
// method:请求方法,NWMethod.POST等
// path:请求地址
// params:请求参数
// success:请求成功回调
// error:请求失败回调
Future requestList<T (NWMethod method, String path, {Map params, Function(List<T ) success, Function(ErrorEntity) error}) async {
try {
Response response = await dio.request(path, queryParameters: params, options: Options(method: NWMethodValues[method]));
if (response != null) {
BaseListEntity entity = BaseListEntity<T .fromJson(response.data);
if (entity.code == 0) {
success(entity.data);
} else {
error(ErrorEntity(code: entity.code, message: entity.message));
}
} else {
error(ErrorEntity(code: -1, message: "未知错误"));
}
} on DioError catch(e) {
error(createErrorEntity(e));
}
}
// 错误信息
ErrorEntity createErrorEntity(DioError error) {
switch (error.type) {
case DioErrorType.CANCEL:{
return ErrorEntity(code: -1, message: "请求取消");
}
break;
case DioErrorType.CONNECT_TIMEOUT:{
return ErrorEntity(code: -1, message: "连接超时");
}
break;
case DioErrorType.SEND_TIMEOUT:{
return ErrorEntity(code: -1, message: "请求超时");
}
break;
case DioErrorType.RECEIVE_TIMEOUT:{
return ErrorEntity(code: -1, message: "响应超时");
}
break;
case DioErrorType.RESPONSE:{
try {
int errCode = error.response.statusCode;
String errMsg = error.response.statusMessage;
return ErrorEntity(code: "$errCode", message: errMsg);
//     switch (errCode) {
//      case 400: {
//       return ErrorEntity(code: errCode, message: "请求语法错误");
//      }
//      break;
//      case 403: {
//       return ErrorEntity(code: errCode, message: "服务器拒绝执行");
//      }
//      break;
//      case 404: {
//       return ErrorEntity(code: errCode, message: "无法连接服务器");
//      }
//      break;
//      case 405: {
//       return ErrorEntity(code: errCode, message: "请求方法被禁止");
//      }
//      break;
//      case 500: {
//       return ErrorEntity(code: errCode, message: "服务器内部错误");
//      }
//      break;
//      case 502: {
//       return ErrorEntity(code: errCode, message: "无效的请求");
//      }
//      break;
//      case 503: {
//       return ErrorEntity(code: errCode, message: "服务器挂了");
//      }
//      break;
//      case 505: {
//       return ErrorEntity(code: errCode, message: "不支持HTTP协议请求");
//      }
//      break;
//      default: {
//       return ErrorEntity(code: errCode, message: "未知错误");
//      }
//     }
} on Exception catch(_) {
return ErrorEntity(code: -1, message: "未知错误");
}
}
break;
default: {
return ErrorEntity(code: -1, message: error.message);
}
}
}
}

使用:

// 返回 LoginEntity
DioManager().request<LoginEntity (
NWMethod.POST,
NWApi.loginPath,
params: {"account": "421789838@qq.com", "password": "123456"},
success: (data) {
print("success data = $data"});
}, error: (error) {
print("error code = ${error.code}, massage = ${error.message}");
}
);
// 返回 List
DioManager().requestList<LoginEntity (
NWMethod.POST,
NWApi.queryListJsonPath,
params: {"account": "421789838@qq.com", "password": "123456"},
success: (data) {
print("success data = $data"});
}, error: (error) {
print("error code = ${error.code}, massage = ${error.message}");
}
);

以上就是本文的全部内容,希望对大家的学习有所帮助。