Java 改造连接失败返回 RetrofitError.response 为空
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Retrofit connection failure returns RetrofitError.response as null
提问by Marc
Using Retrofit 1.6.0, OkHTTP 2.0.0, and OkHTTP-UrlConnection 2.0.0.
使用 Retrofit 1.6.0、OkHTTP 2.0.0 和 OkHTTP-UrlConnection 2.0.0。
I am doing a POST to a service using Retrofit to a URL that does not exist. The failure callback is called, as expected. However, the RetrofitError parameter does not have a response. I would really like to grab the HTTP status code that was returned by using
我正在使用 Retrofit 对不存在的 URL 执行 POST 服务。正如预期的那样，调用失败回调。但是，RetrofitError 参数没有响应。我真的很想获取使用返回的 HTTP 状态代码
error.getResponse().getStatus()
but since getResponse() returns null, I can't.
但由于 getResponse() 返回 null，我不能。
Why is getResponse() null and how can I get the status?
为什么 getResponse() 为 null 以及如何获取状态？
Thanks.
谢谢。
Also, the error I am receiving is UnknownHostException, as expected. Repeat: I am expecting this error. I want to know how to get the HTTP status code or why error.getResponse() returns null.
此外，正如预期的那样，我收到的错误是 UnknownHostException。重复：我期待这个错误。我想知道如何获取 HTTP 状态代码或为什么 error.getResponse() 返回 null。
Edit: Here's some code:
编辑：这是一些代码：
RestAdapterBuilderClass.java
RestAdapter restAdapter = new RestAdapter.Builder()
.setEndpoint("http://badURL.DoesntMatter/");
.setRequestInterceptor(sRequestInterceptor)
.setLogLevel(RestAdapter.LogLevel.FULL)
.build();
sService = restAdapter.create(ServiceInterface.class);
ServiceInterface.java
@POST("/Login")
void login(@Body JsonObject body, Callback<String> callback);
CallbackClass.java
@Override
public void failure(RetrofitError error) {
if (error.getResponse() == null) {
// error.getResponse() is null when I need to get the status code
// from it.
return;
}
}
采纳答案by lyio
When you get an UnknownHostException it means, that you were not able to establish a connection to the server. You cannot, in fact, expect a HTTP status in that case.
当您收到 UnknownHostException 时，这意味着您无法与服务器建立连接。实际上，在这种情况下您不能期望 HTTP 状态。
Naturally you only get a Http response (and with that a status) when you can connect to a server.
当然，当您可以连接到服务器时，您只会收到 Http 响应（以及状态）。
Even when you get a 404 status code, you made a connection to the server. That is not the same as a UnknownHostException.
即使您收到 404 状态代码，您也已连接到服务器。这与 UnknownHostException 不同。
The getResponse() can return null if you didn't get a response.
如果您没有收到响应， getResponse() 可以返回 null。
回答by swanson
RetrofitErrorhas a method called isNetworkError()that you can use to detect a failed request due to network problems. I usually add a small helper method like this:
RetrofitError有一个方法isNetworkError()可以用来检测由于网络问题而失败的请求。我通常会添加一个像这样的小辅助方法：
public int getStatusCode(RetrofitError error) {
if (error.isNetworkError()) {
return 503; // Use another code if you'd prefer
}
return error.getResponse().getStatus();
}
and then use that result to handle any additional failure logic (logout on 401, display error message on 500, etc).
然后使用该结果来处理任何其他故障逻辑（在 401 上注销，在 500 上显示错误消息等）。
回答by mustaq
I am using Retrofit 2. When endpoint url end with "/" as in your case and again in your interface it starts with "/" [@POST("/Login")] causes this problem. Remove the "/" from .setEndpoint() method
我正在使用 Retrofit 2。当端点 url 以“/”结尾时，在你的情况下，再次在你的界面中，它以“/”开头 [@POST("/Login")] 会导致这个问题。从 .setEndpoint() 方法中删除“/”
回答by Peter File
Just to expand on @lyio's answer, I found from Fabric logging that getKind() sometimes returns UNEXPECTED and then if you parse the message you get timeouts and connection issues so I wrote the utility class below.
只是为了扩展@lyio 的答案，我从 Fabric 日志记录中发现 getKind() 有时会返回 UNEXPECTED，然后如果您解析消息，您会遇到超时和连接问题，因此我编写了下面的实用程序类。
public class NetworkUtils {
// Compiled from Fabric events
private static final List<String> networkErrorStrings = new ArrayList<>(Arrays.asList(
"Unable to resolve host",
"Connection closed by peer",
"Failed to connect",
"timeout",
"Connection timed out"));
public static boolean isNetworkError(@Nullable RetrofitError retrofitError) {
if (retrofitError != null) {
if (retrofitError.getKind() != RetrofitError.Kind.NETWORK) {
for (String error : networkErrorStrings) {
if (retrofitError.getMessage().contains(error)) {
return true;
}
}
} else {
return true;
}
}
return false;
}
}
}
