Question

你好我试图缓存我从reddit服务做的GET请求。我用另一个api测试并且工作但我找不到为什么我无法控制缓存的原因。我可以看到缓存数据如何在应用程序设置中上升，当我可以通过互联网连接json时。但是当我关闭互联网连接（飞行模式）时，我收到了这个错误：

01-17 06：00：05.524 17363-17429 / com.amirgb.reddittestapp.debug D / OkHttp： - ＆gt;获得https://www.reddit.com/reddits.json http / 1.1 01-17 06：00：05.524 17363-17429 / com.amirgb.reddittestapp.debug D / OkHttp： - ＆gt;结束 01-17 06：00：05.531 17363-17429 / com.amirgb.reddittestapp.debug D / OkHttp：＆lt; - HTTP FAILED：java.net.UnknownHostException：无法解析主机“www.reddit.com”：没有地址与主机名相关联

我正在测试一个moto g 4 plus api 23我尝试使用https://itunes.apple.com/us/rss/topfreeapplications/limit=20/json服务并且缓存确实有效，所以也许reddit标头有区别？

我的restclient课程：

import android.content.Context;
import android.widget.ImageView;

import com.amirgb.reddittestapp.BuildConfig;
import com.amirgb.reddittestapp.R;
import com.amirgb.reddittestapp.RedditTestApplication;
import com.amirgb.reddittestapp.model.RedditResponse;
import com.amirgb.reddittestapp.util.NetWorkUtils;

import java.io.File;
import java.util.concurrent.TimeUnit;

import okhttp3.Cache;
import okhttp3.CacheControl;
import okhttp3.OkHttpClient;
import okhttp3.Request;
import okhttp3.Response;
import okhttp3.logging.HttpLoggingInterceptor;
import retrofit2.Call;
import retrofit2.Callback;
import retrofit2.Retrofit;
import retrofit2.converter.gson.GsonConverterFactory;

public final class RedditApiService {

    private static IRedditApi mRedditApi;
    private static OkHttpClient mClient;

    /**
     * Inits retrofit
     */
    static {
        HttpLoggingInterceptor interceptor = new HttpLoggingInterceptor();
        interceptor.setLevel(HttpLoggingInterceptor.Level.BODY);

        File httpCacheDirectory = new File(RedditTestApplication.getInstance().getCacheDir(), "reddit");
        Cache cache = new Cache(httpCacheDirectory, 10 * 1024 * 1024);

         mClient = new OkHttpClient.Builder()
                .cache(cache)
                .addInterceptor(chain -> {
                    Request request = chain.request();
                    if (NetWorkUtils.isNetworkAvailable(RedditTestApplication.getInstance())) {
                        request = request.newBuilder()
                                .cacheControl(new CacheControl.Builder()
                                        .maxAge(0, TimeUnit.SECONDS)
                                        .maxStale(365, TimeUnit.DAYS).build())
                                .build();
                    }

                    Response originalResponse = chain.proceed(request);
                    if (NetWorkUtils.isNetworkAvailable(RedditTestApplication.getInstance())) {
                        int maxAge = 60 * 60;
                        return originalResponse.newBuilder()
                                .header("Cache-Control", "public, max-age=" + maxAge)
                                .build();
                    } else {
                        int maxStale = 60 * 60 * 24 * 28;
                        return originalResponse.newBuilder()
                                .header("Cache-Control", "public, only-if-cached, max-stale=" + maxStale)
                                .build();
                    }
                })
                .connectTimeout(60, TimeUnit.SECONDS)
                .writeTimeout(60, TimeUnit.SECONDS)
                .readTimeout(60, TimeUnit.SECONDS)
                .addInterceptor(interceptor)
                .build();

        Retrofit mRetrofit = new Retrofit.Builder()
                .baseUrl(IRedditApi.BASE_URL)
                .addConverterFactory(GsonConverterFactory.create())
                .client(mClient)
                .build();
        mRedditApi = mRetrofit.create(IRedditApi.class);
    }

    /**
     * Get subjects from service api
     *
     * @param callback
     */
    public static void getSubjects(Callback<RedditResponse> callback) {
        Call<RedditResponse> call = mRedditApi.getSubjects();
        call.enqueue(callback);
    }

我的网络工具方法：

public static boolean isNetworkAvailable(Context context) {
    ConnectivityManager cm =
            (ConnectivityManager) context.getSystemService(Context.CONNECTIVITY_SERVICE);
    NetworkInfo activeNetwork = cm.getActiveNetworkInfo();
    return activeNetwork != null &&
            activeNetwork.isConnectedOrConnecting();
}

我的改造界面：

public interface IRedditApi {
String BASE_URL = "https://www.reddit.com";

@GET("/reddits.json")
Call<RedditResponse> getSubjects();}

Reddit响应标题：

accept-ranges→bytes access-control-allow-origin→* access-control-expose-headers→X-Reddit-Tracking，X-Moose cache-control→max-age = 0，必须重新验证 content-encoding→gzip content-length→79113 content-type→application / json;字符集= UTF-8 日期→星期二，2017年1月17日09:16:52 GMT 状态→200 strict-transport-security→max-age = 15552000; includeSubDomains;预紧 vary→accept-encoding 通过→1.1清漆 x-cache→MISS x-cache-hits→0 x-content-type-options→nosniff x-frame-options→SAMEORIGIN x-moose→雄伟壮观 x-reddit-tracking→https://pixel.redditmedia.com/pixel/of_destiny.png?v=W9eORuZE%2BzXXBRZc%2BikbQ8aTR0a7BSLeoE9DDYvuCihjMAifTK%2Bdsr%2F0gX8rDES98kR5xK2vVWc%3D x-served-by→cache-dfw1841-DFW x-timer→S1484644612.225905，VS0，VE254 x-ua-compatible→IE = edge x-xss-protection→1;模式=块

Answer 1

有一个＆＃34;必须重新验证＆＃34;标题，因此您无法直接从缓存中读取

如果您尝试删除它，例如使用charles-proxy，它应该像您期望的那样工作。由于我不知道你想要达到的目的，我无法告诉你最适合你的解决方案。

HTTP FAILED：java.net.UnknownHostException：无法解析主机“www.reddit.com”：没有与主机名关联的地址

1 个答案: