Traversing directories without using recursion?

Question

The Problem I need to write a simple software that, giving certain constraints, appends to a list a series of files. The user could choose between

Answer 1

Based on PATRY Guillaume solution

public static List getFolderTree(File node)
  {
    List directories = new ArrayList();
    if (node.isDirectory())
    {
      directories.add(node);
    }

    for(int i=0; i