使用HTTPS进行连接：服务器重定向次数过多

Question

我正在尝试使用Java程序连接到安全连接URL（https://example.com）以检查站​​点的可用性。通常，我通过禁用代理设置连接到浏览器中的https://example.com。此外，我们已在受信任的根证书中安装证书。我已成功将这些证书添加到Java Keystore。

  import java.net.URL;
    import java.net.URLConnection;
    import java.security.Security.*;
    import com.sun.net.ssl.*;
    import com.sun.*; 

    import javax.net.ssl.HttpsURLConnection;
    import java.security.cert.Certificate;
    import java.io.*;
    import javax.net.ssl.SSLPeerUnverifiedException;
    import org.omg.CORBA_2_3.portable.InputStream;

    public class TestConn {
    public static void main(String args [])
    {
        try{
                 URL hp = new URL("https://example.com");
                HttpsURLConnection hpCon = (HttpsURLConnection)hp.openConnection();

        boolean isProxy = hpCon.usingProxy();
        System.out.println("is using proxy " + isProxy);
        InputStream obj = (InputStream) hpCon.getInputStream();
        while(obj.read()!=-1){
            System.out.println(obj.read_char());

        }
                System.out.println("content >> " + obj.toString());
        }catch (Exception ex){
            ex.printStackTrace();
        }
    }
    }

我遇到了以下错误：

java.net.ProtocolException: Server redirected too many  times (20)
    at sun.net.www.protocol.http.HttpURLConnection.getInputStream(Unknown Source)
    at sun.net.www.protocol.https.HttpsURLConnectionImpl.getInputStream(Unknown Source)
    at TestConn.main(TestConn.java:28)

关于这个例外，有谁可以帮助我？

Answer 1

如果您想查看网站的可用性，您应该使用hpCon.getResponseCode();。响应代码200表示该站点可用。坦率地说，我不知道你的进一步目的。这是修改后的代码，确实得到了输出内容。

import java.io.BufferedReader;
import java.io.InputStream;
import java.io.InputStreamReader;
import java.net.URL;
import javax.net.ssl.HttpsURLConnection;

public class Test {
public static void main(String[] args) {

    try {
        URL hp = new URL("https://godaddy.com");
        HttpsURLConnection hpCon = (HttpsURLConnection) hp.openConnection();

        boolean isProxy = hpCon.usingProxy();
        System.out.println("is using proxy " + isProxy);
        InputStream obj = hpCon.getInputStream();
        BufferedReader br = new BufferedReader(new InputStreamReader(obj));

        String s;
        while ((s = br.readLine()) != null) {
            System.out.println("content >>" + s);
        }

    } catch (Exception ex) {
        ex.printStackTrace();
    }
}
}