import java.net.HttpURLConnection;
import java.net.URL;
import java.util.List;
import java.util.Map;
import java.util.Set;
public class Main{
public static void main(String args[]) throws Exception {
URL url = new URL("http://www.google.com");
HttpURLConnection httpCon = (HttpURLConnection) url.openConnection();
Map> hdrs = httpCon.getHeaderFields();
Set hdrKeys = hdrs.keySet();
for (String k : hdrKeys)
System.out.println("Key: " + k + " Value: " + hdrs.get(k));
}
}