Character.java has obsolete URL reference in comment:
 * ftp://unicode.org/pub/MappingTables/UnicodeData1.1.5.txt

this url no longer exists. it has been replaced by

ftp://ftp.unicode.org/Public/UNIDATA/UNIDATA.TXT

but, since this could also change in the future, its best not
to give a specific url, just refer them to the web site:

http://www.unicode.org/