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

Recursion can always be transformed into a loop.
A quick and dirty possible solution (not tested) follows :

private static void displayDirectory(File node){
    ArraList directories = new ArrayList();
    if (node.isDirectory())
       directories.append (node);    
    // Iterate over the directory list
    Iterator it = directories.iterator();
    while(it.hasNext()){
       File dir  = (File)it.next();           
       // get childs
       String[] subNote = dir.list();
       for(String filename : subNote){
          subNode = new File(node, filename);
          // display current child name
          System.out.println(subNode.getAbsoluteFile());
          // if directory : add current child to the list of dir to process
          if (subnode.isDirectory()){
             directories.append(subNode);
          }
       }
    }
}

please note that the source node should be a directory for anything to be displayed.
Also, this is a breadth-first display. if you want a depth first, you should change the "append" to put the file it just after the current node in the array list.

i'm not sure about the memory consomation, however.
Regards
Guillaume