Flutter app 2.save session

本地保存 方式 使用shared_preferences

参考

https://flutter.io/cookbook/persistence/key-value/

1. Add the dependency 添加依赖

https://pub.dartlang.org/

中查找最新版本

Add this to your package’s pubspec.yaml file:

dependencies:
  shared_preferences: ^0.4.2

更新

flutter packages get

2. 使用 shared_preferences 保存

引入

import 'package:shared_preferences/shared_preferences.dart';

创建 util/DataUtils.dart

import 'package:shared_preferences/shared_preferences.dart';
import 'dart:async';

class DataUtils {
  static final String SP_SESSION = "SESSION";

  static Future<String> getAccessToken() async {
    SharedPreferences sp = await SharedPreferences.getInstance();
    return sp.getString(SP_SESSION);
  }

  static Future<bool> setAccessToken(String session) async {
    SharedPreferences sp = await SharedPreferences.getInstance();
    return await sp.setString(SP_USER_NAME, session);
  }
}

3. LoginPage.dart 中使用 保存用户信息 以及session

1. 登陆完成保存 session

创建单例 保存 app 缓存数据 session

/helper/DataHelper.dart

import 'package:flutter_snap/util/DataUtils.dart';

class DataHelper {
  static final DataHelper _singleton = new DataHelper._internal();

  factory DataHelper() {
    return _singleton;
  }

  DataHelper._internal();

  String session;

  void setSession(String session){
    print(session);

    if (session != this.session){
      this.session = session ;
      var result = DataUtils.setAccessToken(session);
      print("setSession");

      print(result);

    }
  }

  String getSession(){
    if (null == this.session){
      var jsession =  DataUtils.getAccessToken();

      print("getSession");

      print(jsession);

      this.session = jsession.toString();
    }
    return session ;
  }
}

LoginPage.dart

showTips() async {
    //TODO loading
    setState( () {
        _isLoading = true;
      },
    );

    Map map = {
      'user': 'las@sengled.com',
      'pwd': '123456',
      'osType':'android',
      'uuid':'4CC09670-0623-497B-AB82-F48611FA4C42',
      'appCode':'snap',
      'productCode':'snap'
    };

    print(Api.AuthenCross);
    print(json.encode(map));

    String result = await apiRequest(Api.AuthenCross, map);

    Map<String, dynamic> resultMap = json.decode(result);


    if( null != resultMap ){

      if( 0 == resultMap['ret'] || "success" == resultMap['msg']){
        var jsessionId = resultMap['jsessionId'];

        print(jsessionId)   ;
        if( jsessionId.length > 0 ){
          new DataHelper().setSession(jsessionId);
        }

        getUserInfo();

      } else {

      }

    }
  }

LoginPage login 调用DataHelper 保存 session
在 调用 getUserInfo 获取用户信息

2. 获取用户信息 在 head 中添加 session

http 代码

util/NetUtils.dart

http headers 添加 session

class NetUtils {
  

  static Future<String> apiRequest(String url, Map jsonMap) async {
    String  session =   new DataHelper().getSession();
    print(session);
    print(url);
    print(json.encode(jsonMap));

    HttpClient httpClient = new HttpClient();
    HttpClientRequest request = await httpClient.postUrl(Uri.parse(url));
    request.headers.set('content-type', 'application/json');
    if (null != session){
      request.headers.add('Cookie', 'JSESSIONID=' + session.toString());
    }

    request.add(utf8.encode(json.encode(jsonMap)));
    HttpClientResponse response = await request.close();
    // todo - you should check the response.statusCode
    String reply = await response.transform(utf8.decoder).join();
    httpClient.close();
    return reply;
  }
}

LoginPage.dart

Future getUserInfo() async {
    Map map = {};
    String result = await  NetUtils.apiRequest(Api.getUserInfo, map);
    Map<String, dynamic> resultMap = json.decode(result);
    print(resultMap);
    if( null != resultMap ){
      if( 200 == resultMap['messageCode'] || "ok" == resultMap['message']){
        var data = resultMap['data'];
        if ( null != data ){
          num id = data['id'];
          var account = data['account'];
          var nickName = data['nickName'];
          var profile = data['profile'];
          User userInfo = new User(
              id:id,
              name:nickName,
              avatar:profile,
              account:account);

          new UserHelper().setUser(userInfo) ;
          DataUtils.saveUserInfo(userInfo);
        }


      } else {

      }

    }

  }

model/User.dart

class User {
  num id;
  String account;
  String name;
  String avatar;

  User( {this.id, this.name,  this.avatar, this.account} );

  User.fromJson(Map<String, dynamic> json)
      : id = json['id'],
        account = json['account'],
        name = json['name'],
        avatar = json['avatar'] ;

  Map<String, dynamic> toJson() =>
      {
        'id': id,
        'account': account,
        'name': name,
        'avatar': avatar,
      };
}

helper/UserHelper.dart

class UserHelper {
  static final UserHelper _singleton = new UserHelper._internal();
  factory UserHelper() {
    return _singleton;
  }

  UserHelper._internal();
  User user;

  setUser(User u){
    this.user = u;
  }

  User getUser(){
    return user;
  }
}

总结

1. shared_preferences 存储
2. http请求 添加 session