Using JAXB to edit XML documents

Question

I am trying to understand how (and whether) JAXB can be used to make the following types of changes to an existing XML document. I know that I can EDIT an XML document using the set methods that are generated by JAXB (in conformance with the XML Schema), and then I create a Marshaller and marshall the root element object.
However, I have not figured out how to do any of the following:
(i) insert a new element
(ii) delete an existing element
(iii) reorder elements.
Here is an excerpt from an XML document:
<directory name="dir">
<file name="file1"/>
<file name="file2"/>
<file name="file3"/>
</directory>
The order in which the file elements appear is significant.
If I want to add a new file (file4), how would I do this? Where would it be added, at the end? What if I wanted to add it after file2?
If I want to delete file1, I don't know how to do that.
Finally, if I want to move file2 after file3, I don't know how to do that.
It seems as though I need access to the underlying com.sun.xml.bind.util.ListImpl (or similar collection object), which holds the actual file elements when JAXB unmarshals the xml file. However, this seems dangerous and I have gotten a concurrent access exception while trying to do something like this. (Another problem has to do with iterators, where I can't iterate through a list and then make a change to the list w/o messing up the iterator.)
If there are any technologies other than JAXB that might accomplish this, but that provide data binding, I would be happy to hear about it. (I could try SAX/DOM/JDOM/DOM4J or XSLT, I guess, but I like the data binding of JAXB.)

Answer 1

As is typical for me, I answered my own questions.
if you are outside of an iterator, you can simply use the:
add(object)
add(position,object)
remove(object)
methods of the List interface to add and remove elements from the list of elements.
Also, if you use a ListIterator, you can call the add() and remove() methods of ListIterator while iterating through the list.
In order to reorder elements in the list, use:
Collections.swap(list,pos1,pos2). Why this method is not built into the List interface itself is beyond me. This was only added in 1.4, btw.