Thread: sending password form post doesn't work

There is a website from which I want to access the data in my Java program. When opening the site in a browser, instead of the content I want to see, there is a text field for the password and a button for submitting it. After typing in the correct password and pressing the submit button, I can see the content. The URL is still the same. Normally I can get the html data using code like this:

        URL url = new URL("https://wordpress.***.***/***/***/***/");
        HttpURLConnection connection = (HttpURLConnection) url.openConnection();
        connection.setRequestMethod("GET");
        connection.connect();
 
        var reader = new BufferedReader(new InputStreamReader(connection.getInputStream()));
 
        String line;
        while ((line = reader.readLine()) != null) {
            System.out.println(line);
        }

Of course this won't print out the data I want to access. The interesting part is probably this one:

    <form action="https://wordpress.***.***/***/wp-login.php?action=postpass" class="post-password-form" method="post">
<p>Some text:</p>
<p><label for="pwbox-526">Passwort: <input name="post_password" id="pwbox-526" type="password" size="20" /></label> <input type="submit" name="Submit" value="Absenden" /></p>
</form>

After researching a bit about sending form posts in Java, I came up with this code, though now it doesn't print anything:

        URL url = new URL("https://wordpress.***.***/***/wp-login.php?action=postpass");
        HttpURLConnection connection = (HttpURLConnection) url.openConnection();
        connection.setRequestMethod("POST");
        connection.setDoOutput(true);
        connection.setDoInput(true);
 
        String postData = "post_password=*******&Submit=Absenden";
 
        connection.setRequestProperty("Content-Length", postData.length() + "");
        connection.setRequestProperty("Content-Type", "application/x-www-form-urlencoded; charset=UTF-8");
 
        connection.setUseCaches(false);
        connection.connect();
 
        var out = connection.getOutputStream();
        out.write(URLEncoder.encode(postData, StandardCharsets.UTF_8).getBytes());
        out.flush();
        out.close();
 
        var reader = new BufferedReader(new InputStreamReader(connection.getInputStream()));
 
        String line;
        while ((line = reader.readLine()) != null) {
            System.out.println(line);
        }

This is what the network panel looks like in the Microsoft Edge Developer Tools
image.jpg
Does anyone have a solution? This is the first time I'm working with networks in a Java project. I need it for an android app btw.

Solved:
Needed to use HttpClient and change the request header a bit

What response do you get from the server when you run that code with the login attempt?

When running that code it doesnt print anything

Add code to print the response code and the contents of the response header.

Content-Length: [0]

I have no idea why the server didn't send any content.

response code is FOUND
Strange. I've never seen the word FOUND as the response code. It has always been a number like 200 or 404

content length is 20
What is in the content?

Maybe the server does not like the way it is receiving the password and wants to make sure it is talking to a person and not a program.