Comment automatiser la connexion Gmail pour utiliser HttpsURLConnection et Jsoup en Java 8

Je cherche à automatiser la connexion à un site https qui a un formulaire que je dois appeler plus tard. Je suis tombé sur l'exemple ci-dessous qui explique comment se connecter à gmail; Cependant, le problème que j'ai est quel que soit l'identifiant utilisé, j'obtiens toujours 200Ok. quelqu'un peut-il aider à la résolution de ce problème pour moi?

public class HttpUrlConnectionExample {

  private List<String> cookies;
  private HttpsURLConnection conn;

  private final String USER_AGENT = "Mozilla/5.0";

  public static void main(String[] args) throws Exception {

    String url = "https://accounts.google.com/ServiceLoginAuth";
    String gmail = "https://mail.google.com/mail/#inbox";

    HttpUrlConnectionExample http = new HttpUrlConnectionExample();

    // make sure cookies is turn on
    CookieHandler.setDefault(new CookieManager());

    // 1. Send a "GET" request, so that you can extract the form's data.
    String page = http.GetPageContent(url);
    String postParams = http.getFormParams(page, "[email protected]", "password");



    // 2. Construct above post's content and then send a POST request for
    // authentication
    http.sendPost(url, postParams);



    // 2. Construct above post's content and then send a POST request for


    // 3. success then go to gmail.
    String result = http.GetPageContent(gmail);
    System.out.println(result);
  }

  private void sendPost(String url, String postParams) throws Exception {

    URL obj = new URL(url);
    conn = (HttpsURLConnection) obj.openConnection();

    // Acts like a browser
    conn.setUseCaches(false);
    conn.setRequestMethod("POST");
    conn.setRequestProperty("Host", "accounts.google.com");
    conn.setRequestProperty("User-Agent", USER_AGENT);
    conn.setRequestProperty("Accept",
        "text/html,application/xhtml+xml,application/xml;q=0.9,*/*;q=0.8");
    conn.setRequestProperty("Accept-Language", "en-US,en;q=0.5");
    for (String cookie : this.cookies) {
        conn.addRequestProperty("Cookie", cookie.split(";", 1)[0]);
    }
    conn.setRequestProperty("Connection", "keep-alive");
    conn.setRequestProperty("Referer", "https://accounts.google.com/ServiceLogin");
    conn.setRequestProperty("Content-Type", "application/x-www-form-urlencoded");
    conn.setRequestProperty("Content-Length", Integer.toString(postParams.length()));

    conn.setDoOutput(true);
    conn.setDoInput(true);

    // Send post request
    DataOutputStream wr = new DataOutputStream(conn.getOutputStream());
    wr.writeBytes(postParams);
    wr.flush();
    wr.close();

    int responseCode = conn.getResponseCode();
    System.out.println("\nSending 'POST' request to URL : " + url);
    System.out.println("Post parameters : " + postParams);
    System.out.println("Response Code : " + responseCode);

    BufferedReader in =
             new BufferedReader(new InputStreamReader(conn.getInputStream()));
    String inputLine;
    StringBuffer response = new StringBuffer();

    while ((inputLine = in.readLine()) != null) {
        response.append(inputLine);
    }
    in.close();
    // System.out.println(response.toString());

  }

  private String GetPageContent(String url) throws Exception {

    URL obj = new URL(url);
    conn = (HttpsURLConnection) obj.openConnection();

    // default is GET
    conn.setRequestMethod("GET");

    conn.setUseCaches(false);

    // act like a browser
    conn.setRequestProperty("User-Agent", USER_AGENT);
    conn.setRequestProperty("Accept",
        "text/html,application/xhtml+xml,application/xml;q=0.9,*/*;q=0.8");
    conn.setRequestProperty("Accept-Language", "en-US,en;q=0.5");
    if (cookies != null) {
        for (String cookie : this.cookies) {
            conn.addRequestProperty("Cookie", cookie.split(";", 1)[0]);
        }
    }
    int responseCode = conn.getResponseCode();
    System.out.println("\nSending 'GET' request to URL : " + url);
    System.out.println("Response Code : " + responseCode);

    BufferedReader in =
            new BufferedReader(new InputStreamReader(conn.getInputStream()));
    String inputLine;
    StringBuffer response = new StringBuffer();

    while ((inputLine = in.readLine()) != null) {
        response.append(inputLine);
    }
    in.close();

    // Get the response cookies
    setCookies(conn.getHeaderFields().get("Set-Cookie"));

    return response.toString();

  }

  public String getFormParams(String html, String username, String password)
        throws UnsupportedEncodingException {

    System.out.println("Extracting form's data...");

    Document doc = Jsoup.parse(html);

    // Google form id
    Element loginform = doc.getElementById("gaia_loginform");
    Elements inputElements = loginform.getElementsByTag("input");
    List<String> paramList = new ArrayList<String>();
    for (Element inputElement : inputElements) {
        String key = inputElement.attr("name");
        String value = inputElement.attr("value");

        if (key.equals("Email"))
            value = username;
        else if (key.equals("Passwd"))
            value = password;
        paramList.add(key + "=" + URLEncoder.encode(value, "UTF-8"));
                System.out.println(paramList.toString());
    }

    // build parameters list
    StringBuilder result = new StringBuilder();
    for (String param : paramList) {
        if (result.length() == 0) {
            result.append(param);
        } else {
            result.append("&" + param);
        }
    }
    return result.toString();
  }

  public List<String> getCookies() {
    return cookies;
  }

  public void setCookies(List<String> cookies) {
    this.cookies = cookies;
  }

}