title: Java ArrayList: Adding primitive type or its wrapper-class: What's the difference?
body: <p>imagine the following ArrayList in Java:</p>
  
  <pre><code>ArrayList&lt;Integer&gt; u = new ArrayList&lt;Integer&gt;();
  </code></pre>
  
  <p>I want to know if there is a difference when adding new values either as primitive types or as wrapper-classes:</p>
  
  <pre><code>u.add(new Integer(12));
  u.add(12);
  </code></pre>
  
  <p>Thanks in advance!</p>