How can I iterate through the unicode codepoints of a Java String?

So I know about String#codePointAt(int), but it's indexed by the char offset, not by the codepoint offset.

I'm thinking about trying something like:

• using String#charAt(int) to get the char at an index
• testing whether the char is in the high-surrogates range
  • if so, use String#codePointAt(int) to get the codepoint, and increment the index by 2
  • if not, use the given char value as the codepoint, and increment the index by 1

But my concerns are

• I'm not sure whether codepoints which are naturally in the high-surrogates range will be stored as two char values or one
• this seems like an awful expensive way to iterate through characters
• someone must have come up with something better.