Java HTTP 响应代码 200，而它应该是 301

Question

下面的代码快把我逼疯了。它有时 returns 错误的响应代码，我不明白为什么。例如，现实生活中http://www.ebay.com/itm/131709867498returns一个301 Moved Permanently（Chrome和Edge），而下面的代码returns200。提前致谢。（以防万一，我是运行 Java 1.8.0_66。）

HttpURLConnection connection = (HttpURLConnection)new URL("http://www.ebay.com/itm/131709867498").openConnection();

connection.setRequestMethod("HEAD");
connection.setInstanceFollowRedirects(false);

int statusCode = connection.getResponseCode();
System.out.println(statusCode);

Answer 1

当我在 Curl 中运行你的 URL 时，我得到了“200”。为什么您认为它应该返回 301？


url -I "http://www.ebay.com/itm/131709867498"
HTTP/1.1 200 OK
X-EBAY-C-REQUEST-ID: ri=yGq%2BS7ChLgXP,rci=XOZjR%2BAfGDb5BkY5
RlogId: t6ulcpjqcj9%3Feog4d71f%2B66%600-15436278e5c-0x17a
X-Frame-Options: SAMEORIGIN
X-Content-Type-Options: nosniff
X-XSS-Protection: 1; mode=block
Content-Type: text/html;charset=UTF-8
Content-Language: en-US
Content-Length: 0
Server: Server
Date: Thu, 21 Apr 2016 00:10:42 GMT
Connection: keep-alive
Set-Cookie: JSESSIONID=4694AD028535546045A4E2853D7F8B72; Path=/; HttpOnly
Set-Cookie: ebay=%5Esbf%3D%23%5E;Domain=.ebay.com;Path=/
Set-Cookie: dp1=bu1p/QEBfX0BAX19AQA**58f94e02^bl/US5ada8182^;Domain=.ebay.com;Expires=Sat, 21-Apr-2018 00:10:42 GMT;Path=/
Set-Cookie: s=CgAD4ACBXGWwCMzYyNzhlNTcxNTQwYTYyMjg3MDFkNTExZmZiN2MyMGKrI6lP;Domain=.ebay.com;Path=/; HttpOnly
Set-Cookie: nonsession=CgADLAAFXGCGKMQDKACBgfhwCMzYyNzhlNTcxNTQwYTYyMjg3MDFkNTExZmZiN2MyMGIcCAX2;Domain=.ebay.com;Expires=Fri, 21-Apr-2017 00:10:42 GMT;Path=/

Answer 2

您正在使用 "Head" 方法，但浏览器使用 "GET" 方法，如果您更改

connection.setRequestMethod("HEAD");

到

connection.setRequestMethod("GET");

你会看到 301 状态码

Java HTTP 响应代码 200，而它应该是 301

Java HTTP response code 200, while it should be 301

java

http-response-codes