Retrofit with offline mode

RetrofitOfflineMode.java

//-------

public static final String BASE_URL = "https://lateralview.co";
public static final String HEADER_CACHE_CONTROL = "Cache-Control";
public static final String HEADER_PRAGMA = "Pragma";

private Context mContext;

//-------

public Retrofit getRetrofit() {
    // Add all interceptors you want (headers, URL, logging, stetho logs)
    OkHttpClient.Builder httpClient = new OkHttpClient.Builder()
            .addInterceptor(provideOfflineCacheInterceptor())
            .addNetworkInterceptor(provideCacheInterceptor())
            .cache(provideCache());

    return new Retrofit.Builder()
            .baseUrl(BASE_URL)
            .addConverterFactory(GsonConverterFactory.create(new Gson()))
            // Add your adapter factory to handler Errors
            .client(httpClient.build())
            .build();
}

private Cache provideCache() {
    Cache cache = null;

    try {
        cache = new Cache(new File(mContext.getCacheDir(), "http-cache"),
                10 * 1024 * 1024); // 10 MB
    } catch (Exception e) {
        Log.e(TAG, "Could not create Cache!");
    }

    return cache;
}

private Interceptor provideCacheInterceptor() {
    return chain -> {
        Response response = chain.proceed(chain.request());

        CacheControl cacheControl;

        if (isConnected()) {
            cacheControl = new CacheControl.Builder()
                    .maxAge(0, TimeUnit.SECONDS)
                    .build();
        } else {
            cacheControl = new CacheControl.Builder()
                    .maxStale(7, TimeUnit.DAYS)
                    .build();
        }

        return response.newBuilder()
                .removeHeader(HEADER_PRAGMA)
                .removeHeader(HEADER_CACHE_CONTROL)
                .header(HEADER_CACHE_CONTROL, cacheControl.toString())
                .build();

    };
}

private Interceptor provideOfflineCacheInterceptor() {
    return chain -> {
        Request request = chain.request();

        if (!isConnected()) {
            CacheControl cacheControl = new CacheControl.Builder()
                    .maxStale(7, TimeUnit.DAYS)
                    .build();

            request = request.newBuilder()
                    .removeHeader(HEADER_PRAGMA)
                    .removeHeader(HEADER_CACHE_CONTROL)
                    .cacheControl(cacheControl)
                    .build();
        }

        return chain.proceed(request);
    };
}

public boolean isConnected() {
    try {
        android.net.ConnectivityManager e = (android.net.ConnectivityManager) mContext.getSystemService(
                Context.CONNECTIVITY_SERVICE);
        NetworkInfo activeNetwork = e.getActiveNetworkInfo();
        return activeNetwork != null && activeNetwork.isConnectedOrConnecting();
    } catch (Exception e) {
        Log.w(TAG, e.toString());
    }

    return false;
}