2017-07-07 92 views
0

这里有很多关于Retrofit缓存的复杂答案,但没有一个对我有帮助。Retrofit响应缓存

如何缓存来自Retrofit响应的代码响应?

我的应用程序工作正常下载下面的JSON,但我需要为它做一个缓存,我从来没有在Android上做过缓存。

我需要离线打开应用程序,并从我的Retrofit调用中获得结果,就像我在线一样。

public class APIClient { 

public static final String BASE_URL = "https://raw.githubusercontent.com/"; 
private static Retrofit retrofit = null; 

public static Retrofit getClient() { 
    if (retrofit==null) { 
     OkHttpClient.Builder httpClient = new OkHttpClient.Builder(); 
     httpClient.addInterceptor(new Interceptor() { 
      @Override 
      public Response intercept(Interceptor.Chain chain) throws IOException { 
       Request original = chain.request(); 

       Request request = original.newBuilder() 
         .method(original.method(), original.body()) 
         .build(); 
       return chain.proceed(request); 
      } 
     }); 

     OkHttpClient client = httpClient.build(); 
     retrofit = new Retrofit.Builder() 
       .baseUrl(BASE_URL) 
       .addConverterFactory(GsonConverterFactory.create()) 
       .client(client) 
       .build(); 
    } 
    return retrofit; 
}} 

JSON响应非常简单:

{ 
 
    "fruits":[ 
 
     { 
 
     "name":"Apple", 
 
     "image":"https://upload.wikimedia.org/wikipedia/commons/thumb/1/15/Red_Apple.jpg/265px-Red_Apple.jpg", 
 
     "price":35 
 
     }, 
 
     { 
 
     "name":"Banana", 
 
     "image":"https://upload.wikimedia.org/wikipedia/commons/thumb/4/44/Bananas_white_background_DS.jpg/320px-Bananas_white_background_DS.jpg", 
 
     "price":12 
 
     }, 
 
     { 
 
     "name":"Grapes", 
 
     "image":"https://upload.wikimedia.org/wikipedia/commons/thumb/b/bb/Table_grapes_on_white.jpg/320px-Table_grapes_on_white.jpg", 
 
     "price":45 
 
     }, 
 
     { 
 
     "name":"Pineapple", 
 
     "image":"https://upload.wikimedia.org/wikipedia/commons/thumb/c/cb/Pineapple_and_cross_section.jpg/286px-Pineapple_and_cross_section.jpg", 
 
     "price":200 
 
     }, 
 
     { 
 
     "name":"cherry", 
 
     "image":"http://www.desicomments.com/wp-content/uploads/2017/05/Cherry-Image-600x570.jpg", 
 
     "price":13 
 
     }, 
 
     { 
 
     "name":"clementine", 
 
     "image":"http://www.icecreamnation.org/wp-content/uploads/2013/04/Clementine_orange.jpg", 
 
     "price":12.4 
 
     }, 
 
     { 
 
     "name":"olive", 
 
     "image":"https://www.homenaturalcures.com/wp-content/uploads/olive.jpg", 
 
     "price":9.5 
 
     }, 
 
     { 
 
     "name":"tomato", 
 
     "image":"http://cdn2.stylecraze.com/wp-content/uploads/2013/05/tomato-hair-benefits1.jpg", 
 
     "price":8.75 
 
     }, 
 
     { 
 
     "name":"huckleberry", 
 
     "image":"http://farm3.static.flickr.com/2131/2082287810_47339fc93e.jpg", 
 
     "price":11.75 
 
     }, 
 
     { 
 
     "name":"papaya", 
 
     "image":"http://media.mercola.com/assets/images/foodfacts/papaya-nutrition-facts.jpg", 
 
     "price":2.75 
 
     }, 
 
     { 
 
     "name":"lime", 
 
     "image":"https://www.florihana.com/images/stories/virtuemart/product/FLE019%20-%20LIME.jpg", 
 
     "price":5.75 
 
     }, 
 
     { 
 
     "name":"pear", 
 
     "image":"https://www.organicfacts.net/wp-content/uploads/pear.jpg", 
 
     "price":4.75 
 
     } 
 
    ] 
 
}

回答

1

假设服务器方面Cache-Control/If-Modified-Since头,比所有你所要做的就是创建一个Cache对象并设定它到OkHttpClient。改造将照顾其余的。

 

    int cacheSize = 10 * 1024 * 1024; // 10 MB 
    Cache cache = new Cache(getCacheDir(), cacheSize); 

    OkHttpClient okHttpClient = new OkHttpClient.Builder() 
      .cache(cache) 
      .build(); 

    Retrofit.Builder builder = new Retrofit.Builder() 
      .baseUrl("http://10.0.2.2:3000/") 
      .client(okHttpClient) 
      .addConverterFactory(GsonConverterFactory.create()); 

    Retrofit retrofit = builder.build(); 
 

来源:使用改装2.0和okHttp futurestud.io

+0

当我用这个例子从futurestud.io它变得无法解析法对“getCacheDir()”。我应该在这里改变什么? – BlitzkriegBlue

+0

'getCacheDir()'是'Context'类的一种方法,所以你应该使用'Context'对象或'Activity'(它是'Context'的后代)来做到这一点。 – azizbekian

+0

是的,但是在我的班级APIClient上面它并不“适合”。所以我应该在使Call <>的类上创建缓存。在这里说“新手”。 – BlitzkriegBlue

1

中序缓存我们的服务器响应,大家都需要的是OkHttpClient,AddNetworkInterceptor添加缓存拦截器,则不能使用。 AddInterceptor,同时也不一样。

这种方法不需要服务器端操作,也没有其他服务器端的缓存策略,如果服务器有自己的缓存策略代码,应该相应修改以适应服务器。

You can refer this link , it helped me to solve my problem

+0

https://stackoverflow.com/help/how-to-answer – Kondal