I would be interested in the answer to this. But unless you need the string concat "+" operation I would suggest making your own string class that does not check for sync, assuming you don''t need it. I assume that even if it has a lock from the start, the stringbuffer will still check for a lock.
The fanatic is incorruptible: if he kills for an idea, he can just as well get himself killed for one; in either case, tyrant or martyr, he is a monster. --EM Cioran