A DESCRIPTION OF THE REQUEST : On start-up, class ExtendedCharsets instantiates hundreds of Strings and puts them into 3 hashmaps. Better have all those names in a single (maybe 3) well-sorted indexed byte/char array/s, ideally loaded from a data file (pre-generated by JDK make processing). JUSTIFICATION : Filling all the strings in the hashmaps needs some time, and should be superfluous at start-up. It should be sufficient, to only put according names in the cache hashmap when a charset is first instantiated. Start-up of ExtendedCharsets influences JDK start-up time, when extended charset is configured for default charset. See also: http://bugs.sun.com/bugdatabase/view_bug.do?bug_id=6795536