Home » Core Java » net » URLConnection » Get response headers from HTTP request

About Byron Kiourtzoglou

Byron Kiourtzoglou
Byron is a master software engineer working in the IT and Telecom domains. He is an applications developer in a wide variety of applications/services. He is currently acting as the team leader and technical architect for a proprietary service creation and integration platform for both the IT and Telecom industries in addition to a in-house big data real-time analytics solution. He is always fascinated by SOA, middleware services and mobile development. Byron is co-founder and Executive Editor at Java Code Geeks.

Get response headers from HTTP request

With this example we are going to demonstrate how to get response headers from an HTTP request in Java. In short, to get the response headers from an HTTP request you should :

  • Create a URL Object that represents the resource you want to access
  • Use the openConnection() API method of the URL Object to access connection specific parameters for the HTTP request
  • Use the getHeaderFields() API method from the connection Object to get a Name-Value pare Map Object containing all respose headers for the specific HTTP request

You can Iterate over the contents of the header’s Map Object as shown in the code snippet below.

package com.javacodegeeks.snippets.core;

import java.net.URL;
import java.net.URLConnection;
import java.util.Iterator;
import java.util.List;
import java.util.Map;
import java.util.Set;

public class GetResponseHeadersFromHTTPRequest {
	
	public static void main(String[] args) throws Exception {
		
		URL url = new URL("http://www.google.com:80");
		URLConnection conn = url.openConnection();

		Map<String, List<String>> headerFields = conn.getHeaderFields();

		Set<String> headerFieldsSet = headerFields.keySet();
		Iterator<String> hearerFieldsIter = headerFieldsSet.iterator();
		
		while (hearerFieldsIter.hasNext()) {
			
			 String headerFieldKey = hearerFieldsIter.next();
			 List<String> headerFieldValue = headerFields.get(headerFieldKey);
			 
			 StringBuilder sb = new StringBuilder();
			 for (String value : headerFieldValue) {
				 sb.append(value);
				 sb.append("");
			}
			 
			 System.out.println(headerFieldKey + "=" + sb.toString());
			
		}
		
	}

}

Output:

null=HTTP/1.1 200 OK
X-Frame-Options=SAMEORIGIN
Date=Sat, 29 Oct 2011 19:59:40 GMT
Transfer-Encoding=chunked
Expires=-1
X-XSS-Protection=1; mode=block
Set-Cookie=NID=52=k77gRcAV5E3Gh7PIobW26tSHsyc2gBeTEOHastZBxQdvqJ5JwfFCbhEaJh8uQ0bH3PFNvnpeGGtumB8pe1XWMcF7dQC9TugHOgzseBEl6CxOTmcvq_RHGwdQcFq6LUZQ; expires=Sun, 29-Apr-2012 19:59:40 GMT; path=/; domain=.google.gr; HttpOnlyPREF=ID=a372139a705e35a1:FF=0:TM=1319918380:LM=1319918380:S=i8JHod81lVWzINZg; expires=Mon, 28-Oct-2013 19:59:40 GMT; path=/; domain=.google.gr
Content-Type=text/html; charset=ISO-8859-7
Server=gws
Cache-Control=private, max-age=0

This was an example of how to get response headers from an HTTP request in Java.

(No Ratings Yet)
Start the discussion Views Tweet it!

Do you want to know how to develop your skillset to become a Java Rockstar?

Subscribe to our newsletter to start Rocking right now!

To get you started we give you our best selling eBooks for FREE!

 

1. JPA Mini Book

2. JVM Troubleshooting Guide

3. JUnit Tutorial for Unit Testing

4. Java Annotations Tutorial

5. Java Interview Questions

6. Spring Interview Questions

7. Android UI Design

 

and many more ....

 

Receive Java & Developer job alerts in your Area

 

Leave a Reply

avatar
  Subscribe  
Notify of