How to Resolve Jsoup Login Form Submission Issues Due to Missing VIEWSTATE and EVENTVALIDATION Parameters?

Troubleshooting Jsoup Login Form Submission Issues

Problem Statement:

Despite using correct login credentials, the Jsoup code posted below fails to log into the target website, displaying the login page's HTML code instead.

<code class="java">public void connect() {

    try {
        Connection.Response loginForm = Jsoup.connect("https://www.capitaliq.com/CIQDotNet/Login.aspx/login.php")
                .method(Connection.Method.GET)
                .execute();

        org.jsoup.nodes.Document document = Jsoup.connect("https://www.capitaliq.com/CIQDotNet/Login.aspx/authentication.php")
                .data("cookieexists", "false")
                .data("username", "myUsername")
                .data("password", "myPassword")
                .cookies(loginForm.cookies())
                .post();
        System.out.println(document);
    } catch (IOException ex) {
        Logger.getLogger(WebCrawler.class.getName()).log(Level.SEVERE, null, ex);
    }
}</code>

Solution:

In addition to the username, password, and cookies, the target website requires two additional values for login: VIEWSTATE and EVENTVALIDATION. To obtain these values:

<code class="java">Document doc = loginForm.parse();
Element e = doc.select("input[id=__VIEWSTATE]").first();
String viewState = e.attr("value");
e = doc.select("input[id=__EVENTVALIDATION]").first();
String eventValidation = e.attr("value");</code>

Then, add these values to the post request (order doesn't matter):

<code class="java">org.jsoup.nodes.Document document = (org.jsoup.nodes.Document) Jsoup.connect("https://www.capitaliq.com/CIQDotNet/Login.aspx/authentication.php").userAgent("Mozilla/5.0")               
            .data("myLogin$myUsername", "MyUsername")
            .data("myLogin$myPassword, "MyPassword")
            .data("myLogin$myLoginButton.x", "22")                   
            .data("myLogin$myLoginButton.y", "8")
            .data("__VIEWSTATE", viewState)
            .data("__EVENTVALIDATION", eventValidation)
            .cookies(loginForm.cookies())
            .post();</code>

To enable the "Remember Me" feature, add:

<code class="java">.data("myLogin$myEnableAutoLogin", "on")</code>

With these modifications, the login should now succeed as expected.

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