Retrofit + Okhttp是否使用httpCaching作为Android的默认设置？

OkHttpClient v2的正确实现:

int cacheSize = 10 * 1024 * 1024; // 10 MiB
File cacheDir = new File(context.getCacheDir(), "HttpCache");
Cache cache = new Cache(cacheDir, cacheSize);
OkHttpClient client = new OkHttpClient.Builder()
    .cache(cache)
    .build();

看文档

您应该手动创建OkHttpClient并根据需要进行配置.在这种情况下,您应该安装缓存.一旦你有了创建一个OkClient并将其传递给Retrofit的RestAdapter.Builder

此外,没有HTTP POST请求的缓存.但是,GET将被缓存.

已弃用OkHttpClient v2.0.0及更高版本

正如杰西威尔逊指出你需要创建自己的缓存.
以下代码应创建10MB缓存.

File httpCacheDirectory = new File(application.getApplicationContext()
    .getCacheDir().getAbsolutePath(), "HttpCache");

HttpResponseCache httpResponseCache = null;
try {
   httpResponseCache = new HttpResponseCache(httpCacheDirectory, 10 * 1024);
} catch (IOException e) {
   Log.e(getClass().getSimpleName(), "Could not create http cache", e);
}

OkHttpClient okHttpClient = new OkHttpClient();
okHttpClient.setResponseCache(httpResponseCache);
builder.setClient(new OkClient(okHttpClient));

该代码基于Github上的Jesse Wilsons示例.