This week's book giveaway is in the OCAJP 8 forum. We're giving away four copies of OCA Java SE 8 Programmer I Study Guide and have Edward Finegan & Robert Liguori on-line! See this thread for details.
Actually, most of the API classes have overloaded methods / constructors that take a Comparator for custom sorting as well. The TreeMap / TreeSet constructors, Collections.sort and Arrays.sort sure do.