HTTP Authentication issue

Hi,
I am using "Authenticator" to do http authentication, for URL's which
require
http authentication.

Code is as follow:

import java.io.BufferedReader;
import java.io.IOException;
import java.io.InputStream;
import java.io.InputStreamReader;
import java.net.Authenticator;
import java.net.MalformedURLException;
import java.net.PasswordAuthentication;
import java.net.URL;

public class AuthDemo {
  public static void main(String args[]) throws MalformedURLException,
      IOException {
    String urlString = "";
    String username = "";
    String password = "";
    Authenticator.setDefault(new MyAuthenticator(username, password));
    URL url = new URL(urlString);
    InputStream content = (InputStream) url.getContent();
    BufferedReader in = new BufferedReader(new InputStreamReader
(content));
    String line;
    while ((line = in.readLine()) != null) {
      System.out.println(line);
    }
    System.out.println("Done.");
  }

  static class MyAuthenticator extends Authenticator {
    private String username, password;

    public MyAuthenticator(String user, String pass) {
      username = user;
      password = pass;
    }

    protected PasswordAuthentication getPasswordAuthentication() {
      System.out.println("Requesting Host : " + getRequestingHost());
      System.out.println("Requesting Port : " + getRequestingPort());
      System.out.println("Requesting Prompt : " + getRequestingPrompt
());
      System.out.println("Requesting Protocol: "
          + getRequestingProtocol());
      System.out.println("Requesting Scheme : " + getRequestingScheme
());
      System.out.println("Requesting Site : " + getRequestingSite());
      return new PasswordAuthentication(username, password.toCharArray
());
    }
  }
}

Even after specified proper url, username & password, i am still
getting HTTP 401 i.e. unauthorised http error.
I have observed that MyAuthenticator::getPasswordAuthentication() is
not getting called.

Setup Details:
Machine OS: Red Hat Linux
JRE: 1.5.0_05-b05

Can anyone comment this issue?

Thanks,
Suraj