title: Java Collection<Object> or Collection<?>
body: <p>I try use List instead of List </p>
  
  <pre><code>List&lt;?&gt; list = new ArrayList&lt;Integer&gt;();
  ...
  list.add(1); //compile error
  </code></pre>
  
  <p>What i do wrong and how cast new value to Integer? 
   Maybe i shoud use List in my project?</p>