HttpsURLConnection:连接超时错误

Question

我有一个简单的代码,用于设置与谷歌的https连接并打印获得的响应.

import java.io.OutputStreamWriter;
import java.net.URL;

import javax.net.ssl.HttpsURLConnection;


public class SendCertReq 
{
public static void main(String[] args) throws Exception 
{
     URL url = new URL("https://www.google.co.in/");
     HttpsURLConnection conn = (HttpsURLConnection)url.openConnection();
     conn.setRequestMethod("GET");
     conn.setDoOutput(true);
     OutputStreamWriter wr = new OutputStreamWriter(conn.getOutputStream());
     wr.close();
     System.out.println(conn.getResponseMessage());
}
}

我尝试运行它时出现以下错误.

Exception in thread "main" java.net.ConnectException: Connection timed out: connect
at java.net.DualStackPlainSocketImpl.connect0(Native Method)
at java.net.DualStackPlainSocketImpl.socketConnect(Unknown Source)
at java.net.AbstractPlainSocketImpl.doConnect(Unknown Source)
at java.net.AbstractPlainSocketImpl.connectToAddress(Unknown Source)
at java.net.AbstractPlainSocketImpl.connect(Unknown Source)
at java.net.PlainSocketImpl.connect(Unknown Source)
at java.net.SocksSocketImpl.connect(Unknown Source)
at java.net.Socket.connect(Unknown Source)
at sun.security.ssl.SSLSocketImpl.connect(Unknown Source)
at sun.security.ssl.BaseSSLSocketImpl.connect(Unknown Source)
at sun.net.NetworkClient.doConnect(Unknown Source)
at sun.net.www.http.HttpClient.openServer(Unknown Source)
at sun.net.www.http.HttpClient.openServer(Unknown Source)
at sun.net.www.protocol.https.HttpsClient.<init>(Unknown Source)
at sun.net.www.protocol.https.HttpsClient.New(Unknown Source)
at sun.net.www.protocol.https.AbstractDelegateHttpsURLConnection.getNewHttpClient(Unknown Source)
at sun.net.www.protocol.http.HttpURLConnection.plainConnect(Unknown Source)
at sun.net.www.protocol.https.AbstractDelegateHttpsURLConnection.connect(Unknown Source)
at sun.net.www.protocol.http.HttpURLConnection.getOutputStream(Unknown Source)
at sun.net.www.protocol.https.HttpsURLConnectionImpl.getOutputStream(Unknown Source)
at SendCertReq.main(SendCertReq.java:16)

任何人都可以指导我.从早上起我就一直在吃我的头脑.

Answer 1

由于超时不是预期的行为,即使发送格式错误的请求,也没有办法确切地说出错误是什么.这是我用来调试的一般过程.