Authenticator Problem: ProtocolException: Server redirected too many times

Question

My program needs to login to a certain website, and I'm using Authenticator to do this. If I supply valid credentials this works fine. However, my program needs to handle the case of the user entering invalid credentials. The site responds to invalid logins by redirecting to itself. If I type the URL into a browser, I get a login prompt, and if I enter an invalid login, it just reloads the page and gives me a new login prompt.
Since java automatically tries to login to every page with the given authenticator, it gets stuck in a loop. Login, redirected to same site, login again, etc. until this exception is thrown:
java.net.ProtocolException: Server redirected too many times (20)
What's the best way to handle this? I've tried adding HttpURLConnection.setFollowRedirects(false); but it doesn't seem to work (it still redirects).

Answer 1

The URL I'm connecting to is http://webservices.schedulesdirect.tmsdatadirect.com/schedulesdirect/tvlistings/xtvdService
Here is my code. Right now it's set to assume an incorrect login if there was a redirect. It works, but it's not ideal imo.
public int grabListings(InputSource listingsSource, Calendar start, Calendar end, URL serverURL,
               String username, String password, Progress progress){
          Authenticator.setDefault(new TVAuthenticator(username, password, this));
          int response=-1;
          try {
               //HttpURLConnection.setFollowRedirects(false);
               progress.progressMessage = "Connecting to Schedules Direct";
               conn = (HttpURLConnection) serverURL.openConnection();
               conn.setRequestProperty("Accept-Encoding", "gzip");
               conn.setRequestProperty("SOAPAction", "urn:TMSWebServices:xtvdWebService#download");
               conn.setRequestMethod("POST");
               conn.setDoInput(true);
               conn.setDoOutput(true);
               //conn.setRequestProperty("Authorization", "digest "  + (new sun.misc.BASE64Encoder().encode(
               //          (username + ":" + password).getBytes())));
               //conn.setInstanceFollowRedirects(false);
               PrintWriter pw = new PrintWriter(conn.getOutputStream());
               pw.println(buildDownloadSOAPEnvelope(start, end));
               pw.flush();
               pw.close();
               BufferedReader br = null;
               String enc = conn.getHeaderField("Content-encoding");
              if (enc != null && enc.equals("gzip")) {
                  br = new BufferedReader(new InputStreamReader(new GZIPInputStream(conn.getInputStream()), "UTF-8"));
              else {
                   br = new BufferedReader(new InputStreamReader(conn.getInputStream(), "UTF-8"));
              progress.currentProgress = 5;
              progress.progressMessage = "Downloading listings";
              response = conn.getResponseCode();
              System.out.println(response);
               if (response == HttpURLConnection.HTTP_UNAUTHORIZED) {
                    return GRABBER_UNAUTHORIZED;
               if (response == HttpURLConnection.HTTP_OK) {
                    listingsSource.setCharacterStream(br);
                    return GRABBER_OK;
          catch (UnknownHostException e) {
               return GRABBER_CONNECTION_ERROR;
          catch (IOException e) {
               if (redirected) return GRABBER_UNAUTHORIZED;
               else e.printStackTrace();
          return GRABBER_UNKNOWN_ERROR;
     private class TVAuthenticator extends Authenticator {
          private String username, password;
          int count=0;
          HttpGrabber grabber;
          public TVAuthenticator(String user, String pass, HttpGrabber _grabber) {
               username = user;
               password = pass;
               grabber = _grabber;
          protected PasswordAuthentication getPasswordAuthentication() {
               if (count > 0) {
                    grabber.setRedirected(true); //If we were redirected, that means the login failed
                    return null;
               count ++;
               return new PasswordAuthentication(username, password.toCharArray());
     }Edited by: sureshot324 on Oct 15, 2009 10:42 PM