前言

在开发过程中，我们经常会用到网络请求，在flutter框架中，dio框架非常不错，所以今天的文章在dio的基础上搭建一套网络持久化框架，那么在flutter项目中如何搭建一套，高可用性，维护性较高的dio公共请求参数框架呢？

搭建前夕准备

一、基本认知

要持久化那么必然要有存储设备
持久化的数据在app启动后要即使填充到项目中
由于项目中网络请求地址繁多，类型不同，需要持久化的位置不同

二、基于基本认知来找合适的工具&必要点

2.1 持久化的工具：

我的推荐

mmkv
share_prefresence

今天主要用讲解mmkv版本

2.2必要点：

dio拦截器

拦截器是搭建这套持久化的关键

三、准备好如上技能，我们来搭建这套持久化网络框架吧

1、首先要知道有几种类型的公共

  //请求中url后追加公共请求
  static const int urlPresistent = 1;
  //请求头中追加公共请求
  static const int headerPresistent = 2;
  //全部都追加公共请求
  static const int allPresistent = 3;

2、构建缓存参数（为了快速获取）

  static Map<String,Map<String, String?>> headerPersistent = Map();
  static Map<String,Map<String, String?>> urlPersistent = Map();

3、构建mmkv存储结构（加密存储）

static MMKV _store(String baseUrl, int type) => MMKVStore.sysSafeMMKV(name: '${SysConfig.sysPersistent}${baseUrl}_${type.toString()}');

4、构建基本函数

单健值对存储

static void setPersistent(String baseUrl,String key,String? value,{int type = allPresistent}){
    if (type == allPresistent || type == headerPresistent) {
      if (!headerPersistent.containsKey(baseUrl)) {
        headerPersistent[baseUrl] = Map<String, String?>();
      }
      var keyMap = headerPersistent[baseUrl]!;
      keyMap[key] = value;
      _store(baseUrl, headerPresistent).encodeString(key, value??"");
    }
    if (type == allPresistent || type == urlPresistent) {
      if (!urlPersistent.containsKey(baseUrl)) {
        urlPersistent[baseUrl] = Map<String, String?>();
      }
      var keyMap = urlPersistent[baseUrl]!;
      keyMap[key] = value;
      _store(baseUrl, urlPresistent).encodeString(key, value??"");
    }
  }

多健值对存储

static void setPersistentMap(String baseUrl,Map<String, String?> map,{int type = allPresistent}){
    if (type == allPresistent || type == headerPresistent) {
      if (!headerPersistent.containsKey(baseUrl)) {
        headerPersistent[baseUrl] = Map<String, String?>();
      }
      var keyMap = headerPersistent[baseUrl]!;
      keyMap.addAll(map);
      keyMap.forEach((key, value) {
        _store(baseUrl, headerPresistent).encodeString(key, value??"");
      });
    }
    if (type == allPresistent || type == urlPresistent) {
      if (!urlPersistent.containsKey(baseUrl)) {
        urlPersistent[baseUrl] = Map<String, String?>();
      }
      var keyMap = urlPersistent[baseUrl]!;
      keyMap.addAll(map);
      keyMap.forEach((key, value) {
        _store(baseUrl, urlPresistent).encodeString(key, value??"");
      });
    }
  }

参数获取：

  static Map<String, String?>? getPersistent(String baseUrl, {int type = allPresistent}) {
    Map<String, String?>? map;
    if (type == allPresistent || type == headerPresistent) {
      Map<String, String?>? headerMap;
      if (headerPersistent.containsKey(baseUrl)) {
        headerMap = headerPersistent[baseUrl];
      } else {
        headerMap = null;
      }
      if (headerMap != null) {
        if (map == null) {
          map = Map();
        }
        map.addAll(headerMap);
      }
    }
    if (type == allPresistent || type == urlPresistent) {
      Map<String, String?>? urlMap;
      if (urlPersistent.containsKey(baseUrl)) {
        urlMap = urlPersistent[baseUrl];
      } else {
        urlMap = null;
      }

      if (urlMap != null) {
        if (map == null) {
          map = Map();
        }
        map.addAll(urlMap);
      }
    }
    return map;
  }

刷新当前缓存（应用启动刷新）

  static Map<String, String?> _all(String baseurl, int type) {
    var mmkv= _store(baseurl, type);
    var keys = mmkv.allKeys;
    var map = Map<String, String?>();
    keys.forEach((element) {
      var value = mmkv.decodeString(element);
      map[element] = value;
    });
    return map;
  }

  static void flushPersistent(String baseurl, {int type = allPresistent}) {
    if (type == allPresistent || type == headerPresistent) {
      var map = _all(baseurl, headerPresistent);
      headerPersistent[baseurl]?.clear();

      if (!headerPersistent.containsKey(baseurl)) {
        headerPersistent[baseurl] = Map<String, String?>();
      }
      var keyMap = headerPersistent[baseurl]!;
      keyMap.addAll(map);
    }
    if (type == allPresistent || type == urlPresistent) {
      var map = _all(baseurl, urlPresistent);
      urlPersistent[baseurl]?.clear();
      if (!urlPersistent.containsKey(baseurl)) {
        urlPersistent[baseurl] = Map<String, String?>();
      }
      var keyMap = urlPersistent[baseurl]!;
      keyMap.addAll(map);
    }

  }

退出登陆移除持久化

static void removeAllPersistent(String baseurl, {int type = allPresistent}) {
    if (type == allPresistent || type == headerPresistent) {
      headerPersistent[baseurl]?.clear();
      _store(baseurl, headerPresistent).clearAll();
    }
    if (type == allPresistent || type == urlPresistent) {
      urlPersistent[baseurl]?.clear();
      _store(baseurl, urlPresistent).clearAll();
    }
  }

拦截器实现（dio请求拦截管理）

class PresistentInterceptor extends Interceptor {

  @override
  void onRequest(RequestOptions options, RequestInterceptorHandler handler) {
    var urlPersitents = HttpPersistent.getPersistent(options.baseUrl,type: HttpPersistent.urlPresistent);
    var headerPersitents = HttpPersistent.getPersistent(options.baseUrl,
        type: HttpPersistent.headerPresistent);
    headerPersitents?.forEach((key, value) {
      options.headers[key] = value;
    });

    urlPersitents?.forEach((key, value) {
      options.queryParameters[key] = value;
    });
    super.onRequest(options, handler);
  }

}

四、整体代码&事件调用逻辑

整体代码


class HttpPersistent{

  static const int urlPresistent = 1;
  static const int headerPresistent = 2;
  static const int allPresistent = 3;

  static MMKV _store(String baseUrl, int type) => MMKVStore.sysSafeMMKV(name: '${SysConfig.sysPersistent}${baseUrl}_${type.toString()}');
  static Map<String,Map<String, String?>> headerPersistent = Map();
  static Map<String,Map<String, String?>> urlPersistent = Map();

  static void setPersistent(String baseUrl,String key,String? value,{int type = allPresistent}){
    if (type == allPresistent || type == headerPresistent) {
      if (!headerPersistent.containsKey(baseUrl)) {
        headerPersistent[baseUrl] = Map<String, String?>();
      }
      var keyMap = headerPersistent[baseUrl]!;
      keyMap[key] = value;
      _store(baseUrl, headerPresistent).encodeString(key, value??"");
    }
    if (type == allPresistent || type == urlPresistent) {
      if (!urlPersistent.containsKey(baseUrl)) {
        urlPersistent[baseUrl] = Map<String, String?>();
      }
      var keyMap = urlPersistent[baseUrl]!;
      keyMap[key] = value;
      _store(baseUrl, urlPresistent).encodeString(key, value??"");
    }
  }

  static void setPersistentMap(String baseUrl,Map<String, String?> map,{int type = allPresistent}){
    if (type == allPresistent || type == headerPresistent) {
      if (!headerPersistent.containsKey(baseUrl)) {
        headerPersistent[baseUrl] = Map<String, String?>();
      }
      var keyMap = headerPersistent[baseUrl]!;
      keyMap.addAll(map);
      keyMap.forEach((key, value) {
        _store(baseUrl, headerPresistent).encodeString(key, value??"");
      });
    }
    if (type == allPresistent || type == urlPresistent) {
      if (!urlPersistent.containsKey(baseUrl)) {
        urlPersistent[baseUrl] = Map<String, String?>();
      }
      var keyMap = urlPersistent[baseUrl]!;
      keyMap.addAll(map);
      keyMap.forEach((key, value) {
        _store(baseUrl, urlPresistent).encodeString(key, value??"");
      });
    }
  }

  static Map<String, String?>? getPersistent(String baseUrl, {int type = allPresistent}) {
    Map<String, String?>? map;
    if (type == allPresistent || type == headerPresistent) {
      Map<String, String?>? headerMap;
      if (headerPersistent.containsKey(baseUrl)) {
        headerMap = headerPersistent[baseUrl];
      } else {
        headerMap = null;
      }
      if (headerMap != null) {
        if (map == null) {
          map = Map();
        }
        map.addAll(headerMap);
      }
    }
    if (type == allPresistent || type == urlPresistent) {
      Map<String, String?>? urlMap;
      if (urlPersistent.containsKey(baseUrl)) {
        urlMap = urlPersistent[baseUrl];
      } else {
        urlMap = null;
      }

      if (urlMap != null) {
        if (map == null) {
          map = Map();
        }
        map.addAll(urlMap);
      }
    }
    return map;
  }

  static Map<String, String?> _all(String baseurl, int type) {
    var mmkv= _store(baseurl, type);
    var keys = mmkv.allKeys;
    var map = Map<String, String?>();
    keys.forEach((element) {
      var value = mmkv.decodeString(element);
      map[element] = value;
    });
    return map;
  }

  static void flushPersistent(String baseurl, {int type = allPresistent}) {
    if (type == allPresistent || type == headerPresistent) {
      var map = _all(baseurl, headerPresistent);
      headerPersistent[baseurl]?.clear();

      if (!headerPersistent.containsKey(baseurl)) {
        headerPersistent[baseurl] = Map<String, String?>();
      }
      var keyMap = headerPersistent[baseurl]!;
      keyMap.addAll(map);
    }
    if (type == allPresistent || type == urlPresistent) {
      var map = _all(baseurl, urlPresistent);
      urlPersistent[baseurl]?.clear();
      if (!urlPersistent.containsKey(baseurl)) {
        urlPersistent[baseurl] = Map<String, String?>();
      }
      var keyMap = urlPersistent[baseurl]!;
      keyMap.addAll(map);
    }

  }

  static void removeAllPersistent(String baseurl, {int type = allPresistent}) {
    if (type == allPresistent || type == headerPresistent) {
      headerPersistent[baseurl]?.clear();
      _store(baseurl, headerPresistent).clearAll();
    }
    if (type == allPresistent || type == urlPresistent) {
      urlPersistent[baseurl]?.clear();
      _store(baseurl, urlPresistent).clearAll();
    }
  }
}



class PresistentInterceptor extends Interceptor {

  @override
  void onRequest(RequestOptions options, RequestInterceptorHandler handler) {
    var urlPersitents = HttpPersistent.getPersistent(options.baseUrl,type: HttpPersistent.urlPresistent);
    var headerPersitents = HttpPersistent.getPersistent(options.baseUrl,
        type: HttpPersistent.headerPresistent);
    headerPersitents?.forEach((key, value) {
      options.headers[key] = value;
    });

    urlPersitents?.forEach((key, value) {
      options.queryParameters[key] = value;
    });
    super.onRequest(options, handler);
  }

}

1、登陆后，调用存储 HttpPersistent.setPersistent("www.baidu.com","token","123",HttpPersistent.headerPresistent)

2、退出登陆后，调用移除 HttpPersistent.removeAllPersistent("www.baidu.com",,type: HttpPersistent.headerPresistent);

3、应用启动后刷新缓存
HttpPersistent.flushPersistent("www.baidu.com", type: HttpPersistent.headerPresistent);

五、大功告成

如上就构建出一套可靠性高，维护性高的网络持久化框架

更多flutter教程请关注我的IMGeek：www.imgeek.org/people/3369…

跟我学企业级flutter项目：dio网络框架增加公共请求参数&header

前言