 <p>You can take the <code>iterator</code> from the List of <strong>OrdemItem</strong> here:</p> <pre><code>private List&lt;OrderItem&gt; items = new ArrayList&lt;OrderItem&gt;(); </code></pre> <p>and do:</p> <pre><code>public Iterator&lt;OrderItem&gt; iterator() { return items.iterator(); } </code></pre> <p>instead of doing </p> <pre><code>public Iterator&lt;OrderItem&gt; iterator() { return this.iterator(); //How to do this part?? } </code></pre>