Java HttpURLConnection.getInputStream 但得到 401 IOException
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Java HttpURLConnection.getInputStream but get 401 IOException
提问by Weixiang Guan
I am writing a REST client for CouchDB in Java. The following code should be quite standard:
我正在用 Java 为 CouchDB 编写 REST 客户端。以下代码应该是非常标准的：
this.httpCnt.connect();
Map<String, String> responseHeaders = new HashMap<>();
int i = 1;
while (true){
String headerKey = this.httpCnt.getHeaderFieldKey(i);
if (headerKey == null)
break;
responseHeaders.put(headerKey, this.httpCnt.getHeaderField(i));
i++;
}
InputStreamReader reader = new InputStreamReader(this.httpCnt.getInputStream());
StringBuilder responseBuilder = new StringBuilder();
char[] buffer = new char[1024];
while(true){
int noCharRead = reader.read(buffer);
if (noCharRead == -1){
reader.close();
break;
}
responseBuilder.append(buffer, 0, noCharRead);
}
I want to test what happen if the authentication fails. However if the authentication fails, when calling getInputStreamof the HttpURLConnection, I get directly an IOException saying the server responses 401. I suppose if the server responses something, no matter success or failure, it should be able to read whatever the server returns. And I am sure in this case the server does return some text in the body, since if I do a GETto the server using curl and the authentication fails, I get a JSON object as the response body with some error messages in it.
我想测试如果身份验证失败会发生什么。但是，如果身份验证失败，在调用getInputStreamHttpURLConnection 时，我会直接收到一个 IOException，说明服务器响应 401。我想如果服务器响应某些内容，无论成功还是失败，它都应该能够读取服务器返回的任何内容。而且我确信在这种情况下服务器确实会在正文中返回一些文本，因为如果我GET使用 curl 对服务器执行 a并且身份验证失败，我会得到一个 JSON 对象作为响应正文，其中包含一些错误消息。
Is there any way to still get the response body even if 401?
即使 401，有没有办法仍然获得响应正文？
采纳答案by user3001
See this question:
看到这个问题：
"The HttpURLConnection.getErrorStreammethod will return an InputStream which can be used to retrieve data from error conditions (such as a 404), according to the javadocs."
“根据 javadocs，HttpURLConnection.getErrorStream方法将返回一个 InputStream，可用于从错误条件（例如 404）中检索数据。”
回答by Zavior
You need to check for the http status using getResponseCode()to decide if you should use getInputStream()or getErrorStream(). In this case, you need to read the error stream.
您需要检查 http 状态getResponseCode()以决定是否应该使用getInputStream()或getErrorStream()。在这种情况下，您需要读取错误流。
