sorting - Java Comparator for byte array (lexicographic)

Question

I have a hashmap with byte[] keys. I'd like to sort it through a TreeMap.

What is the most effective way to implement the comparator for lexicographic order?

Answer 1

Using Guava, you can use either of:

• UnsignedBytes.lexicographicalComparator()
• SignedBytes.lexicographicalComparator()

The UnsignedBytes comparator appears to have an optimized form using Unsafe that it uses if it can. Comments in the code indicate that it may be at least twice as fast as a normal Java implementation.