2
我想從我的公司API緩存HTTP響應，但它看起來像應用程序不能訪問緩存目錄緩存錯誤：與改造2和3 okhttp
W/System.err的：刪除失敗： ENOENT（沒有這樣的文件或目錄）： /data/user/0/com.appname/cache/cache_file/journal.tmp
W/System.err的： 的java.net.UnknownHostException：無法解析主機 「www.domain.com」：沒有與主機名關聯的地址
我按照這個tutorial。下面是我安裝改造（2.1.0）：
import lu.CompanyName.R;
import lu.CompanyName.interfaces.CompanyNameAPI;
import okhttp3.Cache;
import okhttp3.Interceptor;
import okhttp3.OkHttpClient;
import okhttp3.Request;
import okhttp3.Response;
import okhttp3.logging.HttpLoggingInterceptor;
import retrofit2.Retrofit;
import retrofit2.converter.gson.GsonConverterFactory;
import static okhttp3.logging.HttpLoggingInterceptor.Level.HEADERS;
public class Injector {
private static final String CACHE_CONTROL = "Cache-Control";
private static Retrofit provideRetrofit (String baseUrl) {
return new Retrofit.Builder()
.baseUrl(baseUrl)
.client(provideOkHttpClient())
.addConverterFactory(GsonConverterFactory.create())
.build();
}
private static OkHttpClient provideOkHttpClient() {
return new OkHttpClient.Builder()
.addInterceptor(provideHttpLoggingInterceptor())
.addInterceptor(provideOfflineCacheInterceptor())
.addNetworkInterceptor(provideCacheInterceptor())
.cache(provideCache())
.build();
}
private static Cache provideCache() {
/*
Cache cache = null;
try
{
File dir = CompanyName.getInstance().getExternalCacheDir();
if (dir == null)
dir = CompanyName.getInstance().getCacheDir();
if (dir == null)
Log.e("provideCache", "dir is null");
cache = new Cache(new File(dir, "http-cache"), 10 * 1024 * 1024); // 10 MB
if (cache == null)
Log.e("provideCache", "cache is null");
}
catch (Exception e)
{
Log.e("provideCache", "Could not create Cache!");
}
return cache;*/
/*
File httpCacheDirectory = new File(CompanyName.getInstance().getCacheDir(), "responses");
httpCacheDirectory.getParentFile().mkdirs();
int cacheSize = 10 * 1024 * 1024; // 10 MiB
Cache cache = new Cache(httpCacheDirectory, cacheSize);
try {
cache.initialize();
Iterator<String> iterator = cache.urls();
Log.i("provideCache", "URLs in cacheHttpClient : ");
while (iterator.hasNext()) {
Log.i("provideCache", iterator.next());
}
} catch (IOException e) {
e.printStackTrace();
Log.i("provideCache", "CACHE NOT INIT");
}
return cache;*/
return new Cache(new File(CompanyName.getInstance().getCacheDir(), "cache_file"), 20 * 1024 * 1024);
}
private static HttpLoggingInterceptor provideHttpLoggingInterceptor() {
HttpLoggingInterceptor httpLoggingInterceptor = new HttpLoggingInterceptor();
httpLoggingInterceptor.setLevel(HEADERS);
return httpLoggingInterceptor;
}
private static Interceptor provideCacheInterceptor() {
/*return new Interceptor() {
@Override
public Response intercept (Chain chain) throws IOException {
Response response = chain.proceed(chain.request());
// re-write response header to force use of cache
CacheControl cacheControl = new CacheControl.Builder()
.maxAge(2, TimeUnit.HOURS)
.build();
return response.newBuilder()
.header(CACHE_CONTROL, cacheControl.toString())
.build();
}
};*/
return new Interceptor() {
@Override
public Response intercept(Chain chain) throws IOException {
Request originalRequest = chain.request();
String cacheHeaderValue = CompanyName.getInstance().checkIfHasNetwork()
? "public, max-age=2419200"
: "public, only-if-cached, max-stale=2419200" ;
Request request = originalRequest.newBuilder().build();
Response response = chain.proceed(request);
return response.newBuilder()
.removeHeader("Pragma")
.removeHeader("Cache-Control")
.header("Cache-Control", cacheHeaderValue)
.build();
}
};
}
private static Interceptor provideOfflineCacheInterceptor() {
/*return new Interceptor()
{
@Override
public Response intercept (Chain chain) throws IOException
{
Request request = chain.request();
if (!CompanyName.hasNetwork())
{
CacheControl cacheControl = new CacheControl.Builder()
//.maxStale(7, TimeUnit.DAYS)
.build();
request = request.newBuilder()
.cacheControl(cacheControl)
.build();
}
return chain.proceed(request);
}
};*/
return new Interceptor() {
@Override
public Response intercept(Chain chain) throws IOException {
Request originalRequest = chain.request();
String cacheHeaderValue = CompanyName.getInstance().checkIfHasNetwork()
? "public, max-age=2419200"
: "public, only-if-cached, max-stale=2419200" ;
Request request = originalRequest.newBuilder().build();
Response response = chain.proceed(request);
return response.newBuilder()
.removeHeader("Pragma")
.removeHeader("Cache-Control")
.header("Cache-Control", cacheHeaderValue)
.build();
}
};
}
public static CompanyNameAPI provideCompanyNameAPI() {
return provideRetrofit(CompanyName.getInstance().getString(R.string.base_url)).create(CompanyNameAPI.class);
}
}
我試圖找到在互聯網和計算器的一些解決方案（仍然在上面的代碼註釋），因爲起初我以爲這是一個「緩存控制」重寫問題。
我還向清單添加了權限READ_EXTERNAL_STORAGE和WRITE_EXTERNAL_STORAGE，但它不會更改任何內容。
我錯過了什麼嗎？ （我正在使用Android 6.0.1 API 23在三星進行測試）
不，我已經添加了此權限。事實上，只有當我關閉互聯網連接（飛行模式）時，我纔得到上述錯誤：我的測試包括首次獲取數據（互聯網）以獲取緩存，然後從緩存中獲取數據（互聯網關閉）。 – Bogy