android - okHttp3 response.code() 不会返回 304

Question

我在 Android 应用程序上使用 OkHttp3 来监听网络服务，保持问题的基本性，以下是 trik 的作用:

try(Response response = client.newCall(request).execute()) {
    responseBody = response.body().string();
    responseHeaders = response.headers();

    serviceContent = responseBody; // store response content in class' property
    serviceHeaders = responseHeaders; // store response headers in class' property
    serviceStatusCode = response.code(); // store response status code in class' property
} catch(IOException e) {
    e.printStackTrace();
}

然后在我的 Activity 中，我使用 serviceStatusCode 以不同方式处理网络服务响应。

我正在收听的服务之一是 SkyScanner，它可能会返回 304，表明响应已经创建，您必须使用本地存储的先前响应。

我一切正常，但是当 SkyScanner 返回 304 时，我无法捕捉到它，这是我根据 Activity 中的代码处理响应的方式:

switch(statusCode) {
    case 304: {
        // Get data from local DB
        break;
    }
    case 200: {}
    // And so on
}

问题是 statusCode 是 200(由 response.code() 填充)，即使 Fiddler 说它是 304。为什么 response.code() 返回 304 就不会返回 304 吗？

Answer 1

看看here (section 'Reduce processing') :

On a 304 status, Retrofit2 and OkHttp3 will pretend this response was equal to the last response; the cached response is returned. To notice the 304, check the raw response code:

if (response.isSuccessful() &&
    response.raw().networkResponse() != null &&
    response.raw().networkResponse().code() ==
           HttpURLConnection.HTTP_NOT_MODIFIED) {
    // not modified, no need to do anything.
    return;
}

// parse response here 

Getting the normal (not raw) response code would give you the cached status code, probably 200 OK