I like to use the IntArrayList from Colt. (http://acs.lbl.gov/~hoschek/colt/
Colt provides a set of Open Source Libraries for High Performance Scientific and Technical Computing in Java.
Api for the IntArrayList is: http://acs.lbl.gov/~hoschek/colt/api/cern/colt/list/IntArrayList.html
The IntArrayList can grow dynamically, you use it like this:
IntArrayList intList = new IntArrayList();
for (int i = 0; i < 10; i++)
int myIntArray = intList.elements();
The Colt library has more goodies than this, check it out