HttpUrlConnection proxy authentication gets into redirect loop

Question

I am trying to get contents of an URL through an authenticated proxy. This is the code i am trying to use:

        Authenticator authenticator = new Authenticator() {
            public PasswordAuthentication getPasswordAuthentication() {
                System.out.println("authenticating");
                return (new PasswordAuthentication("username", "password".toCharArray()));
            }
        };
        Authenticator.setDefault(authenticator);
        URL url = new URL("http://www.google.com");
        InetSocketAddress proxyAddress = new InetSocketAddress("address.of.proxy", 6060);
        Proxy proxy = new Proxy(Proxy.Type.HTTP, proxyAddress);
        HttpURLConnection uc = (HttpURLConnection) url.openConnection(proxy);
        uc.connect();
        System.out.println(uc.getResponseCode());

For some reason, the authentication gets into a redirect loop, so the result is the authenticator printing "authenticating" 20 times, then a ProtocolException

java.net.ProtocolException: Server redirected too many  times (20)
at sun.net.www.protocol.http.HttpURLConnection.getInputStream0(HttpURLConnection.java:1846)
at sun.net.www.protocol.http.HttpURLConnection.getInputStream(HttpURLConnection.java:1439)
at java.net.URLConnection.getContent(URLConnection.java:739)
at proxytest.RunThis.main(RunThis.java:29)

The proxy is working with the given credentials, i have tried it through browser. I am trying to get this working for days, i have tried setting system properties, apache httpclient, and anything i could get out of google. Any ideas appreciated. :)

UPDATE:

I tested with WireShark, the proxy authentication details are in the request, but the proxy throws back a 407 error. Again, the credentials are OK, its working perfectly from browser ( i actually copied them from the source code to make sure ).

There is one thing i noticed though. The value of the Proxy-Authorization header differs in one and only one character between the browser and the request sent by java. Can this mean something?

Answer 1

The Authenticator.setDefault(authenticator); must be after the openConnection(proxy);

URL url = new URL("http://www.google.com");
InetSocketAddress proxyAddress = new InetSocketAddress("address.of.proxy", 6060);
Proxy proxy = new Proxy(Proxy.Type.HTTP, proxyAddress);
HttpURLConnection uc = (HttpURLConnection) url.openConnection(proxy);
    Authenticator.setDefault(new Authenticator() {
          protected PasswordAuthentication getPasswordAuthentication() {
            return (new PasswordAuthentication("username", "password".toCharArray()));
          }
        });
uc.connect();
System.out.println(uc.getResponseCode());