title: Caching response data with retrofit2+okhttp3
body: <p>I`m using retrofit_2 (beta4) with okhttp_3 libraries in network requests. And i need to cache response data for situations when network is off and application must show responce data from last identical request. All guides for solving this problem that i found were with okhttp lib (not okhttp_3).
   I tried to solve problem:</p>
  
  <pre><code>public class ApiFactory  {
  
  private static final int CONNECT_TIMEOUT = 45;
  private static final int WRITE_TIMEOUT = 45;
  private static final int READ_TIMEOUT = 45;
  private static final long CACHE_SIZE = 10 * 1024 * 1024; // 10 MB
  
  private static OkHttpClient.Builder clientBuilder;
  static {
      clientBuilder = new OkHttpClient
              .Builder()
              .connectTimeout(CONNECT_TIMEOUT, TimeUnit.SECONDS)
              .readTimeout(READ_TIMEOUT, TimeUnit.SECONDS)
              .writeTimeout(WRITE_TIMEOUT, TimeUnit.SECONDS)
              .cache(new Cache(MyApp.getInstance().getCacheDir(), CACHE_SIZE)) // 10 MB
              .addInterceptor(new Interceptor() {
                  @Override
                  public Response intercept(Chain chain) throws IOException {
                      Request request = chain.request();
                      if (MyApp.getInstance().isNetwConn()) {
                          request = request.newBuilder().header("Cache-Control", "public, max-age=" + 60).build();
                      } else {
                          request = request.newBuilder().header("Cache-Control", "public, only-if-cached, max-stale=" + 60 * 60 * 24 * 7).build();
                      }
                      return chain.proceed(request);
                  }
              });
  }
  
  @NonNull
  public static ApiRequestService getApiRequestService() {
      return getRetrofitDefault().create(ApiRequestService.class);
  }
  
  @NonNull
  private static Retrofit getRetrofitDefault() {
      return new Retrofit.Builder()
              .baseUrl(NetworkUrls.URL_MAIN)
              .addConverterFactory(GsonConverterFactory.create())
              .callbackExecutor(Executors.newFixedThreadPool(5))
              .callbackExecutor(Executors.newCachedThreadPool())
              .callbackExecutor(new Executor() {
                  private final Handler mHandler = new Handler(Looper.getMainLooper());
  
                  @Override
                  public void execute(Runnable command) {
                      mHandler.post(command);
                  }
              })
              .client(clientBuilder.build())
              .build();
  }
  }
  </code></pre>
  
  <p>but this doesnt work. All requests work well when network is ON, but not return cache data when network is OFF. Please, help to solve this problem.</p>