Flutter网络请求与JSON

GitHub - dio是一个强大的Dart Http请求库

path/param/options(配置headers/timeout/baseurl等)

///await返回一个Response(Future),包含data,headers,request(本次请求信息),statusCode
response = await request(
      "/test",
      data: {"id": 12, "name": "xx"},
      options: Options(method: "GET"),
  );

封装成单例

import 'dart:io';//http
import 'package:dio/dio.dart';//http
import 'dart:convert';//json
import 'package:crypto/crypto.dart';//MD5
import 'package:convert/convert.dart';//MD5
import 'package:flustars/flustars.dart';//本地储存sputil

//单例网络请求库(封装dio)
class DioUtil {
  static final DioUtil _singleton = DioUtil._init();
  static Dio _dio;

  BaseOptions _options = defaultOptions();
  
  static DioUtil getInstance() {
    return _singleton;
  }
  
  factory DioUtil() {
    return _singleton;
  }

  DioUtil._init() {
    _dio = new Dio(_options);
  }

  static BaseOptions defaultOptions() {
    BaseOptions options = new BaseOptions();
    options.contentType = ContentType.parse("application/x-www-form-urlencoded");
    options.responseType = ResponseType.json;
    options.connectTimeout = 1000 * 10;
    options.receiveTimeout = 1000 * 20;
    options.queryParameters = {"token":SpUtil.getString("UserToken")};//公共参数
    options.headers = {"platform":"ios"};//请求头
    return options;
  }

  Options _checkOptions(method, options) {
    if (options == null) {
      options = new Options();
    }
    options.method = method;
    return options;
  }

  //HTTP请求
  Future request<T>(String method,
                    String path,
                    {data,Options options,CancelToken cancelToken}) async{
    Options currentOptions = options;
    currentOptions.headers = {"sign":generateMd5(json.encode(data))};//签名..
    //关键API
    Response response = await _dio.request(path,
                                           data: data,
                                           options: _checkOptions(method, currentOptions),
                                           cancelToken: cancelToken);
    if (response.statusCode == HttpStatus.ok || response.statusCode == HttpStatus.created) {
      try {
        return BaseRespModel.fromJson(_decodeData(response));
      } catch (e) {
        return new Future.error(
          new DioError(
            response: response,
            message: "data parsing exception...",
            type: DioErrorType.RESPONSE
          )
        );
      }
    } else {
      return new Future.error(
        new DioError(
          response: response,
          message: "statusCode: $response.statusCode, serverError",
          type: DioErrorType.RESPONSE
        )
      );
    }
    //HTTP下载
    Future<Response> download(String urlPath,savePath,
                              {ProgressCallback onProgress,
                              CancelToken cancelToken,
                              data,
                              Options options}){
      return _dio.download(urlPath, savePath,
                          onReceiveProgress: onProgress,
                          cancelToken: cancelToken,
                          data: data,
                          options: options);                           
    }
  }

  /// decode response data.
  Map<String, dynamic> _decodeData(Response response) {
    if (response == null ||
        response.data == null ||
        response.data.toString().isEmpty) {
      return new Map();
    }
    return json.decode(response.data.toString());
  }

  // md5 加密
  String generateMd5(String data) {
    var content = new Utf8Encoder().convert(data);
    var digest = md5.convert(content);
    // 这里其实就是 digest.toString()
    return hex.encode(digest.bytes);
  }
}

//统一返回模型
class BaseRespModel<T> {
  String status;
  int code;
  String msg;
  T data;

  BaseRespModel(this.status, this.code, this.msg, this.data);

  BaseRespModel.fromJson(Map<String, dynamic> json)
      : status = json['status'],
        code = json['code'],
        msg = json['msg'],
        data = json['data'];

  @override
  String toString() {
    StringBuffer sb = new StringBuffer('{');
    sb.write("\"status\":\"$status\"");
    sb.write(",\"code\":$code");
    sb.write(",\"msg\":\"$msg\"");
    sb.write(",\"data\":\"$data\"");
    sb.write('}');
    return sb.toString();
  }
}

///请求方法枚举
class Method {
  static final String get = "GET";
  static final String post = "POST";
  static final String put = "PUT";
  static final String head = "HEAD";
  static final String delete = "DELETE";
  static final String patch = "PATCH";
}

---

Dart内置::dart:convert::库，包含简单JSON编码和解码。

• 解码：Map<String, dynamic> map = json.decode(jsonString);
• 编码：String jsonString = JSON.encode(model);

class LoginReq {
  String username;
  String password;

  LoginReq(this.username, this.password);

  LoginReq.fromJson(Map<String, dynamic> json)
      : username = json['username'],
        password = json['password'];

  Map<String, dynamic> toJson() => {
        'username': username,
        'password': password,
      };

  @override
  String toString() {
    return '{' +
        " \"username\":\"" +
        username +
        "\"" +
        ", \"password\":\"" +
        password +
        "\"" +
        '}';
  }
}

---

thanks for your reading~