Writing an ArrayList back to an XML File
<p>When my activity starts I check for an existing data file and if there isn't one I call a web service that provides a blank one to begin with. The file is read into an ArrayList collection and the user makes changes as needed. Now I am in need of advice for the best approach. </p>

<p>Should I try to match the updated contents in the ArrayList to the element in the XML file (there is an ID field that could be used for matching) or should I just write out the ArrayList overwriting the old xml file? No worries about maintaining a hx.</p>

<p>If I write out the file (what I'm thinking is the way to go) do I have to decorate everything in the DataObject class (ie all the properties) as serializable or just at the class level. Do I also somehow need to mark the ArrayList collection serializable as well?</p>
