HttpURLConnection Class in Java

HttpURLConnection

Java provides a subclass of URLConnection that provides support for HTTP connections. This class is called a HttpURLConnection. You obtain an HttpURLConnection in the same way just shown, by calling openConnection() on a URL object, but you must cast the result to HttpURLConnection. Once you have obtained a reference to an HttpURLConnection object, you can use any of the methods inherited from URLConnection.

HttpURLConnection Methods

static boolean getFollowRedirects(): Returns true if redirects are automatically followed and false otherwise. This feature is on by default.

String getRequestMethod(): Returns a string representing how URL requests are made. The default is GET. Other options, such as POST,
are available.

int getResponseCode() throws IOException: Returns the HTTP response code. –1 is returned if no response code can be obtained. An IOException is thrown if the connection fails.

String getResponseMessage() throws IOException: Returns the response message associated with the response code. Returns null if no message is available. An IOException is thrown if the connection fails.

static void setFollowRedirects(boolean how): If how is true, then redirects are automatically followed. If how is false, redirects are not automatically followed. By default, redirects are automatically followed.

void setRequestMethod(String how) throws ProtocolException: Sets the method by which HTTP requests are made to that specified by how. The default method is GET, but other options, such as POST, are available.

Demonstrate HttpURLConnection Program

import java.net.*;
import java.io.*;
import java.util.*;
class Demo
{
public static void main(String args[]) throws Exception
{
URL hp = new URL("https://webeduclick.com/");
HttpURLConnection hpCon = (HttpURLConnection) hp.openConnection();
System.out.println("Request method is " + hpCon.getRequestMethod());
System.out.println("Response code is " + hpCon.getResponseCode());
System.out.println("Response Message is " + hpCon.getResponseMessage());
Map<String, List> hdrMap = hpCon.getHeaderFields();
Set hdrField = hdrMap.keySet();
System.out.println("\nHere is the header:");
for(String k : hdrField)
{
System.out.println("Key: " + k + " Value: " + hdrMap.get(k));
}
}
}