Beware - I'm not a Java coder.
Reading through some of [link|http://java.sun.com/products/jdk/1.1/docs/api/java.lang.String.html|Sun's docs] on String, it seems that strings are "immutable" so you have to do the conversion another way (as I understand the writeup). StringBuffer seems to have some of the functionality you'd expect, but doesn't list any conversions.
[link|http://gcc.gnu.org/ml/java-patches/2001-q2/msg00260.html|Here] some patches which talk about ints to strings and strings to ints. Maybe that'll help.
Good luck.
Cheers,
Scott.