Critical Description
I was digging some test failures with testRandomHugeStrings that occurred since the upgrade to ICU4J 60.2 which happen to boil down to this bug: http://bugs.icu-project.org/trac/ticket/13512 which is fixed but not released yet.
In short an int[] is shared across several threads while it shouldn't. As a consequence, ICUTokenizer may sometimes return corrupt tokens. I pinged on the issue to know when a release fixing this bug is expected.