HttpURLConnection getHeaderFieldKey(int) in Java

getHeaderFieldKey(int): This method is available in the java.net.HttpURLConnection class of Java.

Syntax:

String java.net.HttpURLConnection.getHeaderFieldKey(int n)

This method takes one argument. This method returns the key for the nth header field.

Some implementations may treat the 0th header field as special, i.e. as the status line returned by the HTTP server.

Parameters: One parameter is required for this method.

n: an index, where n >=0.

Returns: the key for the nth header field, or null if the key does not exist.

Exceptions: NA

Approach

Java

package com.HttpURLConnection;

import java.io.IOException;
import java.net.HttpURLConnection;
import java.net.URL;

public class HttpURLConnectiongetHeaderFieldKey {
    public static void main(String[] args) throws IOException {
        URL url = 
          new URL("https://beingcodeexpert.blogspot.com/");
        HttpURLConnection httpURLConnection = 
                  (HttpURLConnection) url.openConnection();

        int n = 10;

        System.out.println(httpURLConnection.getHeaderFieldKey(n));

    }
}

Output:

Alt-Svc

Some other methods of HttpURLConnection

HttpURLConnection Status Code: Some of the status codes of HttpURLConnection. example HttpURLConnection.HTTP_ACCEPTED, HttpURLConnection.HTTP_BAD_GATEWAY, etc.

disconnect(): This method indicates that other requests to the server are unlikely in the near future.

getErrorStream(): This method returns the error stream if the connection failed but the server sent useful data nonetheless.

HttpURLConnection.getFollowRedirects(): This method returns a boolean indicating whether or not HTTP redirects (3xx) should be automatically followed.

getHeaderField(int): This method returns the value for the nth header field.

getHeaderFieldDate(String, long): This method Returns the value of the named field parsed as a date. The result is the number of milliseconds since January 1, 1970, GMT represented by the named field.

getHeaderFieldKey(int): This method returns the key for the nth header field.

getInstanceFollowRedirects(): This method returns the value of this HttpURLConnection instanceFollowRedirects field.

getPermission(): This method returns a SocketPermission object representing the permission necessary to connect to the destination host and port.

getRequestMethod(): This method gets the request method.

getResponseCode(): This method gets the status code from an HTTP response message.

getResponseMessage(): This method gets the HTTP response message, if any, returned along with the response code from a server.

setAuthenticator(Authenticator): This method supplies an Authenticator to be used when authentication is requested through the HTTP protocol for this HttpURLConnection.If no authenticator is supplied, the default authenticator will be used.

setChunkedStreamingMode(int): This method is used to enable the streaming of an HTTP request body without internal buffering when the content length is not known in advance.

setFixedLengthStreamingMode(int): This method is used to enable the streaming of an HTTP request body without internal buffering when the content length is known in advance.

setFixedLengthStreamingMode(long): This method is used to enable the streaming of an HTTP request body without internal buffering when the content length is known in advance.

HttpURLConnection.setFollowRedirects(boolean): This method sets whether HTTP redirects (requests with response code 3xx) should be automatically followed by this class.

setInstanceFollowRedirects(boolean): This method sets whether HTTP redirects (requests with response code 3xx) should be automatically followed by this HttpURLConnection instance.

setRequestMethod(String): This method sets the method for the URL request, as one of •GET •POST •HEAD •OPTIONS •PUT •DELETE •TRACE are legal, subject to protocol restrictions.

usingProxy(): This method indicates if the connection is going through a proxy.