Actually, that's not correct, and it's the exact same mistake I made when using that API. codePointAt returns the codepoint at index i, where i is measured in 16-bit chars, which means you could index into the middle of a surrogate pair.

The correct version is:

  for (int i = 0; i < string.length(); i = string.offsetByCodePoints(i, 1))
  {
     int codepoint = string.codePointAt(i);
  }

Java 8 seems to have acquired a codePoints() method on the CharSequence interface which seems to do the same thing.

But this just adds to the fact, proper Unicode string processing is a pain :).