Assign Values To Nodes Read From XML Using Java?

i am trying to assign unique values to nodes read from XML file.. eg: consider this XML file:
 
<breakfast_menu>
<food>
<name>Belgian Waffles</name>
<price>$5.95</price>
<description> ...Strong Belgian waffles...</description>
<calories>650</calories>

[code]....

now assigning these nodes "a unique value" has to be done following the LSDX labelling pattern i.e:

To the document element we first give an “a”.As there is no parent node for the document element, we assign “0” at the front of that “a” . “0a” is the unique code for the document element (breakfast_menu). For the children nodes of “0a”, we continue with the next level of the XML tree which is “1” then the code of its parent node which is “a” and a concatenation “.” . We then add a letter “b” for the first child, letter “c” for the second child, “d” for the third child and so on.Unique codes for children nodes of “0a” shall be “1a.b”, “1a.c”, “1a.d”, etc.Hence foe the above given XML the mapping would look something like this:

0a breakfast_menu
1a.b food
2ab.b name
2ab.c price
2ab.d description
2ab.e calories
2ab.f chef
3abf.b chef1
3abf.c chef2
1a.c food
2ac.b name
2ac.c price
2ac.d description
2ac.e calories
2ac.f chef
3acf.b chef1
3acf.c chef2

For more samples about LSDX labelling : 1.) Section 3.1 LSDX Labelling on this link: [URL]

2.) Fig 3 on page 1189 on this link:[URL]

right now i am using SAX parser to read xml and get the nodes in their hierarchical order..now the problem is that i have to assign these specific value to their respective nodes using java.