Java可以在脱机时使用OKHttp进行改造以使用缓存数据

Java可以在脱机时使用OKHttp进行改造以使用缓存数据

编辑改造2.x：

OkHttp Interceptor

是脱机时访问缓存的正确方法：

1）创建拦截器：

private static final Interceptor REWRITE_CACHE_CONTROL_INTERCEPTOR = new Interceptor() {    @Override public Response intercept(Chain chain) throws IOException {        Response originalResponse = chain.proceed(chain.request());        if (Utils.isNetworkAvailable(context)) { int maxAge = 60; // read from cache for 1 minute return originalResponse.newBuilder()         .header("Cache-Control", "public, max-age=" + maxAge)         .build();        } else { int maxStale = 60 * 60 * 24 * 28; // tolerate 4-weeks stale return originalResponse.newBuilder()         .header("Cache-Control", "public, only-if-cached, max-stale=" + maxStale)         .build();        }    }

2）安装客户端：

OkHttpClient client = new OkHttpClient();client.networkInterceptors().add(REWRITE_CACHE_CONTROL_INTERCEPTOR);//setup cacheFile httpCacheDirectory = new File(context.getCacheDir(), "responses");int cacheSize = 10 * 1024 * 1024; // 10 MiBCache cache = new Cache(httpCacheDirectory, cacheSize);//add cache to the clientclient.setCache(cache);

3）将客户添加到改造中

Retrofit retrofit = new Retrofit.Builder()        .baseUrl(base_URL)        .client(client)        .addConverterFactory(GsonConverterFactory.create())        .build();

另请检查@kosiara-Bartosz Kosarzycki的答案。您可能需要从响应中删除一些标头。

OKHttp 2.0.x（检查原始答案）：
由于OKHttp 2.0.x HttpResponseCache是Cache，所以setResponseCache是setCache。因此，您应该setCache这样：

        File httpCacheDirectory = new File(context.getCacheDir(), "responses");        Cache cache = null;        try { cache = new Cache(httpCacheDirectory, 10 * 1024 * 1024);        } catch (IOException e) { Log.e("OKHttp", "Could not create http cache", e);        }        OkHttpClient okHttpClient = new OkHttpClient();        if (cache != null) { okHttpClient.setCache(cache);        }        String hostURL = context.getString(R.string.host_url);        api = new RestAdapter.Builder()     .setEndpoint(hostURL)     .setClient(new OkClient(okHttpClient))     .setRequestInterceptor()     .build()     .create(MyApi.class);