Here is the current code in my application:
String ids = str.split("/");
String.split(String) won't create regexp if your pattern is only one character long. When splitting by single character, it will use specialized code which is pretty efficient.
StringTokenizer is not much faster in this particular case.
Here's a bug report and a commit. This wasn't that long ago so it won't affect you, if you are using older versions (probably anything other than oracle7 or openjdk7). I've made a simple benchmark here.
$ java -version java version "1.8.0_20" Java(TM) SE Runtime Environment (build 1.8.0_20-b26) Java HotSpot(TM) 64-Bit Server VM (build 25.20-b23, mixed mode) $ java Split split_banthar: 1231 split_tskuzzy: 1464 split_tskuzzy2: 1742 string.split: 1291 StringTokenizer: 1517