使用Retrofit 2.0.x进行HTTP缓存

1> Amr Barakat..：

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最后我得到了答案.

网络拦截器应如下:

public class CachingControlInterceptor implements Interceptor {
    @Override
    public Response intercept(Chain chain) throws IOException {
        Request request = chain.request();

        // Add Cache Control only for GET methods
        if (request.method().equals("GET")) {
            if (ConnectivityUtil.checkConnectivity(YaootaApplication.getContext())) {
                // 1 day
               request = request.newBuilder()
                        .header("Cache-Control", "only-if-cached")
                        .build();
            } else {
                // 4 weeks stale
               request = request.newBuilder()
                        .header("Cache-Control", "public, max-stale=2419200")
                        .build();
            }
        }

        Response originalResponse = chain.proceed(request);
        return originalResponse.newBuilder()
            .header("Cache-Control", "max-age=600")
            .build();
    }
}

然后安装缓存文件就这么简单

long SIZE_OF_CACHE = 10 * 1024 * 1024; // 10 MiB
Cache cache = new Cache(new File(context.getCacheDir(), "http"), SIZE_OF_CACHE);
OkHttpClient client = new OkHttpClient();
client.cache(cache);
client.networkInterceptors().add(new CachingControlInterceptor());

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OkHttpClient client = new OkHttpClient.Builder().cache(cache).networkInterceptor(new CachingControlInterceptor()).build();

2> iagreen..：

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在您CachingControlInterceptor,您创建新请求,但从未实际使用它们.您调用newBuilder并忽略结果,因此标题修改永远不会实际发送到任何位置.尝试这些值分配request,然后,而不是调用proceed上chain.request()调用它request.

public class CachingControlInterceptor implements Interceptor {
    @Override
    public Response intercept(Chain chain) throws IOException {
        Request request = chain.request();

        // Add Cache Control only for GET methods
        if (request.method().equals("GET")) {
            if (ConnectivityUtil.checkConnectivity(getContext())) {
                // 1 day
                request = request.newBuilder()
                    .header("Cache-Control", "only-if-cached")
                    .build();
            } else {
                // 4 weeks stale
                request = request.newBuilder()
                    .header("Cache-Control", "public, max-stale=2419200")
                    .build();
            }
        }

        Response originalResponse = chain.proceed(request);
        return originalResponse.newBuilder()
            .header("Cache-Control", "max-age=600")
            .build();
    }
}