URLConnection: getHeaderField(int n)

import java.io.IOException;
import java.net.MalformedURLException;
import java.net.URL;
import java.net.URLConnection;

public class MainClass {
  public static void main(String args[]) {
    URL u;
    URLConnection uc;
    String header;

    try {
      u = new URL("http://www.java2s.com");
      uc = u.openConnection();
      for (int j = 1;; j++) {
        header = uc.getHeaderField(j);
        if (header == null)
          break;
        System.out.println(uc.getHeaderFieldKey(j) + " " + header);
      }
    } catch (MalformedURLException e) {
      System.err.println("not a URL I understand.");
    } catch (IOException e) {
      System.err.println(e);
    }
  }

}