POST gets two answers, only got headers from 2nd... Please help!

Question

Hello!
In this attempt to make a software that connects to a webserver (youtube), authenticates and manages a user's address book, I'm using the HttpURLConnection for sending POST data and getting back an answer. Understanding the basics is ok, it works from a Java point of view, but... PLaying with http gets a bit tricky :-)
I've been trying to understand for hours now, and here's the problem: The only HttpURLConnection in use receives a first answer, (with the good data) then a few ms after, it receives a second answer (without that good data).
The headers are read the following way:
Map> headers = http.getHeaderFields();
for (String key : headers.keySet()) {
    for (String value : headers.get(key)) {
        System.out.println(key + ": " + value);
}(see, I've made nothing new)
The system.out.println only outputs the Set-Cookie headers of the second response. A network packet sniffer shows these two responses:
Frame 9 and Frame 18:
{color:#000000}6 {HTTP:1, TCP:0, IPv4:0} 192.168.1.3 208.117.236.70 HTTP HTTP:Request, POST /login{color}
7 {HTTP:1, TCP:0, IPv4:0} 192.168.1.3 208.117.236.70 HTTP HTTP:HTTP Payload, URL: /login
{color:#3366ff}9 {HTTP:1, TCP:0, IPv4:0} 208.117.236.70 192.168.1.3 HTTP HTTP:Response, HTTP/1.1, Status Code = 303, URL: /login{color}
11 {HTTP:1, TCP:0, IPv4:0} 208.117.236.70 192.168.1.3 HTTP HTTP:HTTP Payload, URL: /login
16 {HTTP:3, TCP:2, IPv4:0} 192.168.1.3 208.117.236.70 HTTP HTTP:Request, GET /index
{color:#3366ff}18 {HTTP:3, TCP:2, IPv4:0} 208.117.236.70 192.168.1.3 HTTP HTTP:Response, HTTP/1.1, Status Code = 200, URL: /index {color}
Frame n°
6 being the post request (headers),
7 the payload of the request (i.e. username, password action_login, etc.),
9 is the the answer containing the needed Set-Cookies ("LOGIN_INFO"),
11 the payload of that answer (contains nothing relevant),
16 hmm not sure about its purpose,
18 is the "second" response to the post request.
Frame 18 does contain a few Set-Cookie headers, but these are useless (i.e. GEO tag, etc. which are different between every request). However, I can't find a way to "prevent" my instance of HttpURLConnection to recover further responses... I tried to put
setRequestProperty("Connection", "close");instead of "keep-alive", but no, doesn't help :(
Then I thought it was a header's fault in frame 9: "Location" which would impose a redirect and did expect the following code to prevent "getting" or whatever send another response:
setFollowRedirects(false); Ok. It's a bit early to call it a happy end... I really need help for this!
Thanks a lot for your time!
Edited by: Neurone-shortage on Feb 7, 2009 4:16 AM

Answer 1

Have a look at the status code of your POST request. It's 303 (See other), which is a redirect. Either your request data is missing some data, or you are sending your request to a wrong URL.
I think, the redirect points to /index, that's why HttpUrlConnection transparently request /index for you, which results in the second response.
Cheers
Henrik