Standard algorithm to parse XML with DOM

Hi,


   Using methods from the Node class you can parse an entire DOM tree. I 
found a nice tutorial at:

http://www.troubleshooters.com/tpromag/200103/codexercises.htm#_domwalkerjava 


   Is there an "official" implementation (a Java class) of such an 
algorithm ? Is there a class that would make this easier - perhaps such 
a class should allow the navigation of DOM using XPATH expressions ?


Regards,
Razvan