Java EE (Java Enterprise Edition) General Discussion

I'm writing a standalone desktop application that reads and stores data as XML files. Eventually, it might be converted to use some web services, but it's not a priority right now.

What I need to do is to use an XML file, which could be large, as kind of a database -- there are many entries, each with a unique identifier, and the application will query the file to find those it needs to match and returns those as objects I'm mapping.

At the moment, because this is a personal project and I'm using it to learn more technologies, I'm trying to (somewhat artificially) restrict myself to the pure Sun APIs. So far, my investigations have pointed to JAXP (by including Java EE 5 libraries) with StAX (including JAX-WS). Which raises two questions:

1) To do this "right", do I really need to bundle my app with the entire JaveEE+Metro stack?
2) Is there a better solution than StAX that's fully Java 5 compliant, even if it means stepping out of the Sun box? I haven't found many references to other solutions that are more recent than 2004. Is parsing XML on an app that has nothing to do with an appserver that uncommon?