使用 http 响应头的 Flutter Cache JSON 响应 [英] Flutter Cache JSON response using http response header

问题描述

我正在尝试为服务器 JSON 响应创建和使用缓存.

类似于 volley 响应缓存的功能.https://stackoverflow.com/a/32022946/1993001 在 Android

我使用 DIO 进行网络操作.

解决方案

您可以使用基于 Dio 请求的拦截器创建自己的缓存.

您可以自己创建:

import 'package:dio/dio.dart';类 CacheInterceptor 扩展拦截器 {缓存拦截器();var _cache = new Map();@覆盖onRequest(RequestOptions options) 异步 {退货选项；}@覆盖onResponse(响应响应)异步{_cache[response.request.uri] = 响应；}@覆盖onError(DioError e) 异步{print('onError: $e');if (e.type == DioErrorType.CONNECT_TIMEOUT || e.type == DioErrorType.DEFAULT) {var cachedResponse = _cache[e.request.uri];如果(缓存响应！= null){返回缓存响应；}}返回 e;}}

然后将其用于:

final dio = Dio()..interceptors.add(CacheInterceptor());

或者只是检查库:https://pub.dev/packages/dio_cache

I'm trying to create and use a cache for a server JSON response.

something like volley response caching does. https://stackoverflow.com/a/32022946/1993001 in Android

I am using DIO for network operations.

解决方案

You can you create your own cache with Interceptors on top of Dio requests.

You can create in on your own:

import 'package:dio/dio.dart';

class CacheInterceptor extends Interceptor {
  CacheInterceptor();

  var _cache = new Map<Uri, Response>();

  @override
  onRequest(RequestOptions options) async {
    return options;
  }

  @override
  onResponse(Response response) async {
    _cache[response.request.uri] = response;
  }

  @override
  onError(DioError e) async{
    print('onError: $e');
    if (e.type == DioErrorType.CONNECT_TIMEOUT || e.type == DioErrorType.DEFAULT) {
      var cachedResponse = _cache[e.request.uri];
      if (cachedResponse != null) {
        return cachedResponse;
      }
    }
    return e;
  }
}

and then use it with:

final dio = Dio()..interceptors.add(CacheInterceptor());   

or just check the library: https://pub.dev/packages/dio_cache

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