Header field

Question

Didn't know where to post this post, but im a newbie, so ill post it among the other newbie posts ;)
My question: what is a header field? Im trying to use the method getHeaderField(String), and I want the value of the string (in the header field?) back. This is what I wrote:
URL url = new URL("http://www.somesite.com/somepage.html");
URLConnection urlconnection = url.openConnection();
String s1 = urlconnection.getHeaderField("Some string");
System.out.println(s1);
So I want the value of the "some string" (which lies in the header, or??), but I only get the value 'null'. Is this correct?
Thanks

Answer 1

Try this and then modify it for your own useimport java.net.*;
import java.util.*;
public class ShowURLHeaders {
    public ShowURLHeaders(String m_url)
        try {
            URL url = new URL(m_url);
            URLConnection urlconnection = url.openConnection();
            Map headers = urlconnection.getHeaderFields();
            Set keys = headers.keySet();
            Iterator it = keys.iterator();
            while (it.hasNext()) {
                String key = (String ) it.next();
                Object value = headers.get(key);
                System.out.println(key + " = " + value.toString());
        } catch (Exception e) {
            // Do something meaningful here.
    public static void main(String[] args)
        ShowURLHeaders ut = new ShowURLHeaders(args[0]);
}