title: Grails get controller parameters
body: <p>I do an AJAX request with some data. I pass a list (for example, [6, 9]). When I print all parameters </p>
  
  <pre><code>println params
  </code></pre>
  
  <p>in controller, I get:</p>
  
  <pre><code>[books[]:[6, 9], action:someAction, controller:someController]
  </code></pre>
  
  <p>but when I do</p>
  
  <pre><code>println params.books
  </code></pre>
  
  <p>I get <code>null</code>. Why??
  Who can I get [6, 9] as a result.</p>
  
  <p>P.S I am using grails 2.2.2</p>