title: spring portlet mvc: model attribute is null despite being modelAttribute?
body: <p>In my rendermapping I put a User object in my model<code>(model.addAttribute)</code>.
  In the coupled JSP I do:</p>
  
  <pre><code>&lt;form:form action="x" method="post" modelAttribute="user"&gt;
  Username: ${user.username}
  Age: ${age}
  This information is correct: &lt;input type="checkbox" id="correctInformation"/&gt;
  &lt;input type="submit" value="Submit"/&gt;
  &lt;/form:form&gt;
  </code></pre>
  
  <p>However in the method mathing x when I retrieve the user object using an <code>@ModelAttribute</code> tag the user object is a new instance instead of the one used in the form (the username is empty etc).</p>
  
  <p>Does anyone know why this happens and the solution?</p>
  
  <p>edit:
  I can use <code>&lt;input type:hidden path="username"/&gt;</code> and it works but that isn't really that clean... Is there a better solution?</p>