title: Hibernate locking a arraylist of items
body: <pre><code>List &lt;Student&gt; st = session.createQuery ("select ids from students where a = :a")
                          .setString("a", value)
                          .list();
  
  //Errors out saying that ArrayList is an unknown entity
  session.lock(st, LockMode.UPGRADE); 
  </code></pre>
  
  <p>Students itself extends Serializable.  How do you lock an arraylist of serailizables in Hibernate?</p>