Creating Nested Lists
<p>How do I create nested lists in java? so I have a factory method below which will pass a list to the constructor of the ROOM class. But I need to associate each wall with a window, So when I iterate over the list in the constructor it knows that a certain window belongs to a certain wall?.</p>

<pre><code>public static Room RoomU(){
    List&lt;Room&gt; RoomU = new ArrayList&lt;Room&gt;();

    // THESE TWO SHOULD BE PAIRED AND SO ON...
    RoomU.add(new Walls(Height, Width));
    RoomU.add(new Windows(Height,Width));

    RoomU.add(new Walls(Height, Width));
    RoomU.add(new Windows(Height,Width));

    RoomU.add(new Walls(Height, Width));
    RoomU.add(new Windows(Height,Width));

    RoomU.add(new Walls(Height, Width));
    RoomU.add(new Windows(Height,Width));

    RoomU.add(new Walls(Height, Width));
    RoomU.add(new Windows(Height,Width));

    return new Room(RoomU);
}
</code></pre>
