Login to a website using httpURLConnection

Question

Hello,
I would like to write a java program that connects to a website, logs in by sending relevant data to the javascript I copy-pasted below and then retrieves the information of the webpage reached after successful login.
<form action="/us/user.html" method="post" class="loginbg">
<script type="text/javascript">
// <![CDATA[
function makeFocus(el)
     switch(el.name)
          case "login_user":      if(el.value == 'Loginname')
                    el.value = '';
                    el.style.textAlign = 'left';
                    el.style.fontSize = '11px';
          break;
          case "login_pwd":      if(el.value == 'Password')
                    el.value = '';
                    el.style.textAlign = 'left';
                    el.style.fontSize = '11px';
                    el.type = "password";
          break;
function makeBlur(el)
     switch(el.name)
          case "login_user":      if(el.value == '')
               el.style.textAlign = 'center';
               el.style.fontSize = '9px';
               el.value = 'Loginname';
          break;
          case "login_pwd":      if(el.value == '')
               el.style.textAlign = 'center';
               el.style.fontSize = '9px';
               el.type = "text";
               el.value = 'Password';
          break;
// ]]>
</script>
<img src="design/user/login.png" alt="Login" title="Login" />
<input type="text" class="name" name="login_user" id="login_user" value="Loginname" onfocus="makeFocus(this);" onblur="makeBlur(this);" style="text-align:left; font-size:11px;" />
<input type="password" class="password" name="login_pwd" id="login_pwd" value="Password" onfocus="makeFocus(this);" onblur="makeBlur(this);" style="text-align:left; font-size:11px;" />
<a href="user,register.html"><img class="regist pngfix" src="design/user/button_regist.png" alt="Regisrieren" title="Registrieren" /></a>
<input class="submit" type="submit" name="send" value="Go!" />
</form>
<script type="text/javascript">
// <![CDATA[
if(document.getElementById('login_user'))
     var el = document.getElementById('login_user');
     if(el.value == 'Loginname')
          el.style.textAlign = 'center';
          el.style.fontSize = '9px';
     el = document.getElementById('login_pwd');
     if(el.value == 'Password')
          el.style.textAlign = 'center';
          el.style.fontSize = '9px';
          el.type = "text";
// ]]>
</script>
{code}                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                           

Answer 1

Read up on HTML and HTTP CGI subsection.
Basically, through the POST, the browser will send an HTTP Request with attached form data to http://[domain]/us/user.html.
All you need is that information and read the HTTP Response.
A typical POST to a server will look like this:
POST /someURL.html HTTP/1.1
Content-Type: text/plain
Content-Length: 68
username=testuser
password=letmein
hiddenfield1=loginform
...