OkHttp响应缓存不起作用

Question

in my android application I am using retrofit for making network download, also I am using OkHttp to cache the response, given below is the code that I wrote

 private RestAdapter buildRestAdapter(String baseUrl, Context ctx) {
    RestAdapter.LogLevel logLevel = RestAdapter.LogLevel.FULL;
    RestAdapter.Builder builder = new RestAdapter.Builder();
    builder.setLogLevel(logLevel);

    if (!TextUtils.isEmpty(baseUrl))
        builder.setEndpoint(baseUrl);

    builder.setRequestInterceptor(new RequestInterceptor() {
        @Override
        public void intercept(RequestFacade request) {
            int maxStale = 60 * 60 * 24 * 28;
            request.addHeader("Cache-Control",
                    "public, only-if-cached, max-stale=" + maxStale);
        }
    });

    File httpCacheDirectory = new File(ctx.getCacheDir(), "responses");
    Cache cache = new Cache(httpCacheDirectory, 10 * 1024 * 1024);
    OkHttpClient okHttpClient = new OkHttpClient();

    if (cache != null) {
        okHttpClient.setCache(cache);
    }
    builder.setClient(new OkClient(okHttpClient));
    return builder.build();
}

the problem here is when I am making an API call I'm getting failure response and the Error says 504 Unsatisfiable Request (only-if-cached)

what could be the issue here ? any help will be appreciated

Answer 1

By having "only-if-cached" in the Cache-Control directive the client won't contact the server, it's just going to check the cache and return the 504 when it cannot find a cache entry match.

How to solve it?

Handling the 504 response with a new request without the client's Cache-Control header. Or just removing the "only-if-cached" if it's not the intented behaviour.