Pre handling in new Java version scheme

// When comparing two version strings, a string with a pre-release
// identifier is always less than one with an equal $VNUM but no such
// identifier. Pre-release identifiers are compared numerically when
// they consist only of digits, and lexicographically otherwise.
if(pre == null && other.pre != null) {
  return 1;
}
if(pre != null && other.pre == null) {
  return -1;
}
if(pre == null /* implicit && o.pre == null */) {
  return 0;
}
// neither pre nor o.pre are null
if(pre.equals(other.pre)) {
  return 0;
}

int value;
try {
  int thisPreAsInt = Integer.parseInt(pre);
  int otherPreAsInt = Integer.parseInt(other.pre);
  // compare numerically
  value = thisPreAsInt - otherPreAsInt;
}
catch(NumberFormatException ex) {
  // compare lexicographically
  value = pre.compareTo(other.pre);
}
if(value < 0) {
  return -1;
}
if(value > 0) {
  return 1;
}

return 0;