Store interface in array list java
<p>I am learning java. I am trying to use composite design pattern. I am trying to use
following logic. ( Don't laugh I know it is very basic :) )</p>

<pre><code>Item -&gt; interface
Folder -&gt; class
File -&gt; class
</code></pre>

<p>In folder class, can I create an arraylist of Item to store files information?</p>

<pre><code>ArrayList&lt;Item&gt; info = ArrayList&lt;Item&gt;();
</code></pre>

<p>Or should I use Folder Arraylist?</p>

<pre><code>ArrayList&lt;Folder&gt; info = ArrayList&lt;Folder&gt;();
</code></pre>

<p>I don't know if interface can store real data as there is no variable just
function definitions.</p>

<p>Thanks for helping a newbie :)</p>
