UTF-8 String class for java

Question

I need to hold lots of string objects in memory (hundreds of MB) and I want to hold them in UTF-8 format since in most cases it will require half of the memory the default implementation use.
The default String class requires for a 12 characters string 60 bytes (See http://blog.griddynamics.com/2010/01/java-tricks-reducing-memory-consumption.html).
Most of my Strings are 10-20 characters long.
I wonder if there is some open source library which offers a wrapper for such strings?
I know how to convert String to UTF-8 byte array but I'm looking for a wrapper class which will provide all needed utilities functions (Hash, Equal, toString, fromString, etc).

Answer 1

Apache Avro has an UTF8 wrapper class which implements CharSequence, but I don't know the memory consumption of such objects

Hadoop has the Text class which has quite the kind of interface you desire