Retrofit cache 404 response

Question

I am using retrofit cache with okhttp3 as described in this answer : https://stackoverflow.com/a/23503804/6212796, here's my intercepter

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();
        }
    }

http client:

OkHttpClient client = new OkHttpClient();
client.networkInterceptors().add(REWRITE_CACHE_CONTROL_INTERCEPTOR);

    File httpCacheDirectory = new File(context.getCacheDir(), "responses");
    int cacheSize = 10 * 1024 * 1024; // 10 MiB
    Cache cache = new Cache(httpCacheDirectory, cacheSize);
    client.setCache(cache);

and the caching is working fine, but once I get a 404 response from the server retrofit get stuck with this response even if the server come to life again.

here's the log when the server is on :

and this is the response when the server is down :

and this when it is up again :

hmm, since the server said it not change (http 304), retrofit take cache data — hakim, Dec 02 '17 at 14:14
I am not quite sure why the server it is not? if you use etag may be the etag value is not changed. (see in your 2nd screenshot it 304 for some reason) — hakim, Dec 02 '17 at 14:32
I figured out that the problem appear when the server go down and work again without any change in the api response but if changed the data get updated .@hakim — Ahmed Esameddeen, Dec 02 '17 at 16:13

score 1 · Accepted Answer · answered Aug 14 '18 at 09:03

I had the same error in OkHttp 3.10.0. I fixed it by removing the response from cache manually. I created class in okhttp3 package. (It's important!)

package okhttp3;

import android.content.Context;

import java.io.File;


class CacheUtil {
    static void remove(Context context, Request request) {
        try {
        Cache cache = new Cache(new File(context.getCacheDir(), "responses"), (10 * 1024 * 1024));//your cache folder
        cache.remove(request);
        } catch (Exception e) {
        }
    }
}

It can be added to your retrofit call enqueue, like this:

    call.enqueue(new Callback<City>() {
        @Override
        public void onResponse(Call<City> call, Response<City> response) {
            if(response.isSuccessful()) {
                //execute success code
            } else {
                if (response.code() == 404) {
                    CacheUtil.remove(context, response.raw().request());
                }
            }
        }

        @Override
        public void onFailure(Call<City> call, Throwable t) {
            //execute failure code
        }
    });

Or it can be added to interceptor (which has to be added to OkHttpClient.Builder) like this:

new Interceptor() {
    @Override
    public Response intercept(Chain chain) throws IOException {
        Request request = chain.request();
        Response response = chain.proceed(request);
        if (response.code() == 404) {
            CacheUtil.remove(context, request);
        }
        return response;
    }
}

May be this will help somebody.

Retrofit cache 404 response

1 Answers1