Java HTTPURLConnection不跟随从HTTP重定向到HTTPS
我不明白为什么Java HttpURLConnection
不遵循从HTTP到HTTPS URL的HTTP重定向。我使用以下代码在https://httpstat.us/上获取页面:
import java.net.URL;import java.net.HttpURLConnection;
import java.io.InputStream;
public class Tester {
public static void main(String argv[]) throws Exception{
InputStream is = null;
try {
String httpUrl = "http://httpstat.us/301";
URL resourceUrl = new URL(httpUrl);
HttpURLConnection conn = (HttpURLConnection)resourceUrl.openConnection();
conn.setConnectTimeout(15000);
conn.setReadTimeout(15000);
conn.connect();
is = conn.getInputStream();
System.out.println("Original URL: "+httpUrl);
System.out.println("Connected to: "+conn.getURL());
System.out.println("HTTP response code received: "+conn.getResponseCode());
System.out.println("HTTP response message received: "+conn.getResponseMessage());
} finally {
if (is != null) is.close();
}
}
}
该程序的输出为:
Original URL: http://httpstat.us/301Connected to: http://httpstat.us/301
HTTP response code received: 301
HTTP response message received: Moved Permanently
对http://httpstat.us/301的请求返回以下(缩短的)响应(这似乎绝对正确!):
HTTP/1.1 301 Moved PermanentlyCache-Control: private
Content-Length: 21
Content-Type: text/plain; charset=utf-8
Location: https://httpstat.us
不幸的是,Java HttpURLConnection不遵循重定向!
回答:
仅当重定向使用相同的协议时,才遵循重定向。(请参见源代码中的followRedirect()方法。)无法禁用此检查。
即使我们知道它是HTTP的镜像,但从HTTP协议的角度来看,HTTPS还是其他完全不同的未知协议。未经用户批准而进行重定向是不安全的。
例如,假设将应用程序设置为自动执行客户端身份验证。用户期望匿名访问,因为他正在使用HTTP。但是,如果他的客户不经询问就遵循HTTPS,则他的身份将显示给服务器。
以上是 Java HTTPURLConnection不跟随从HTTP重定向到HTTPS 的全部内容, 来源链接: utcz.com/qa/431792.html