Retrofit - Okhttp client Wie man die Antwort zwischenspeichert

Question

Ich versuche, die Antwort von HTTP-Aufrufen von Retrofit (v 1.9.0) mit OkHttp (2.3.0) zu cachen. Es hat immer die Netzwerkanrufe gemacht, wenn ich versuche, einen Anruf ohne Internet dann java.net.UnknownHostException zu machen.

RestClient

public class RestClient { 
public static final String BASE_URL = "http://something.example.net/JSONService"; 
private com.ucc.application.rest.ApiService apiService; 

public RestClient() { 
    Gson gson = new GsonBuilder() 
      .setDateFormat("yyyy'-'MM'-'dd'T'HH':'mm':'ss'.'SSS'Z'") 
      .create(); 

    RequestInterceptor requestInterceptor = new RequestInterceptor() { 

     @Override 
     public void intercept(RequestFacade request) { 
      request.addHeader("Accept", "application/json"); 
      int maxAge = 60 * 60; 
      request.addHeader("Cache-Control", "public, max-age=" + maxAge); 
     } 
    }; 

    RestAdapter restAdapter = new RestAdapter.Builder() 
      .setLogLevel(RestAdapter.LogLevel.FULL) 
      .setEndpoint(BASE_URL) 
      .setClient(new OkClient(OkHttpSingleTonClass.getOkHttpClient())) 
      .setConverter(new GsonConverter(gson)) 
      .setRequestInterceptor(requestInterceptor) 
      .build(); 

    apiService = restAdapter.create(com.ucc.application.rest.ApiService.class); 
} 

public com.ucc.application.rest.ApiService getApiService() { 
    return apiService; 
} 

} 

OkHttpSingleTonClass

public class OkHttpSingleTonClass { 


private static OkHttpClient okHttpClient; 

private OkHttpSingleTonClass() { 
} 

public static OkHttpClient getOkHttpClient() { 
    if (okHttpClient == null) { 
     okHttpClient = new OkHttpClient(); 
     createCacheForOkHTTP(); 
    } 
    return okHttpClient; 
} 

private static void createCacheForOkHTTP() { 
    Cache cache = null; 
    cache = new Cache(getDirectory(), 1024 * 1024 * 10); 
    okHttpClient.setCache(cache); 
} 

public static File getDirectory() { 
    final File root = new File(Environment.getExternalStorageDirectory() + File.separator + "UCC" + File.separator); 
    root.mkdirs(); 
    final String fname = UserUtil.CACHE_FILE_NAME; 
    final File sdImageMainDirectory = new File(root, fname); 
    return sdImageMainDirectory; 
} 

} 

MyActivity

Request request = new Request.Builder() 
      .cacheControl(new CacheControl.Builder() 
        .onlyIfCached() 
        .maxAge(60 * 60, TimeUnit.SECONDS) 
        .build()) 
      .url(RestClient.BASE_URL + Constants.GET_ABOUT_US_COLLECTION + "?userid=59e41b02-35ed-4962-8517-2668b5e8dae3&languageid=488d8f13-ef7d-4a3a-9516-0e0d24cbc720") 
      .build(); 
    Log.d("url_request", RestClient.BASE_URL + Constants.GET_ABOUT_US_COLLECTION + "/?userid=10"); 
    com.squareup.okhttp.Response forceCacheResponse = null; 
    try { 
     forceCacheResponse = OkHttpSingleTonClass.getOkHttpClient().newCall(request).execute(); 
    } catch (IOException e) { 
     e.printStackTrace(); 
    } 
    if (forceCacheResponse.code() != 504) { 
     // The resource was cached! Show it. 
     Log.d("From", "Local"); 
     Toast.makeText(AboutUs.this, "Local", Toast.LENGTH_SHORT).show(); 
    } else { 
     // The resource was not cached. 
     Log.d("From", "Network"); 
     Toast.makeText(AboutUs.this, "Network", Toast.LENGTH_SHORT).show(); 
     getAbouUsDetails();//This will use the Apiservice interface to hit the server. 

    } 

folgte ich this. Aber ich kann nicht arbeiten. Es trifft einfach vom Server. Was mache ich falsch?

Answer 1

Nach Retrofit 1.9.0, die OkClient verwendet, hat keine Caching-Unterstützung. Wir müssen OkHttpClient Instanz von Square OkHttpClient Bibliothek verwenden.

Sie können compile 'com.squareup.okhttp:okhttp:2.3.0'

Vor allem Nachrüst-Caches durch Response-Header wie

Cache-Control:max-age=120,only-if-cached,max-stale

** 120 Sekunden kompilieren.

Sie können mehr über Header lesen here.

Caching-Header werden meist durch Server-Antwort angewiesen. Versuchen Sie, Cache-Header in Servern zu implementieren. Wenn Sie keine Option haben, ja Nachrüstung hat es.

private static final Interceptor REWRITE_CACHE_CONTROL_INTERCEPTOR = new Interceptor() { 
    @Override 
    public Response intercept(Chain chain) throws IOException { 
     Response originalResponse = chain.proceed(chain.request()); 
     return originalResponse.newBuilder() 
       .header("Cache-Control", String.format("max-age=%d, only-if-cached, max-stale=%d", 120, 0)) 
       .build(); 
    } 
}; 

Wo zwischenzuspeichern:

private static void createCacheForOkHTTP() { 
    Cache cache = null; 
    cache = new Cache(getDirectory(), 1024 * 1024 * 10); 
    okHttpClient.setCache(cache); 
} 

// returns the file to store cached details 
private File getDirectory() { 
    return new File(“location”); 
} 

Abfangjäger zum OkHttpClient Instanz hinzufügen:

okHttpClient.networkInterceptors().add(REWRITE_CACHE_CONTROL_INTERCEPTOR); 

Und schließlich OkHttpClient zum RestAdapter hinzufügen:

RestAdapter.setClient(new OkClient(okHttpClient)); 

Und Sie können durch this Folie für mehr Referenz gehen.