http://www.oracle.com/technetwork/java/javase/documentation/codeconventions-136091.html#262
Indentation
Four spaces should be used as the unit of indentation. The exact construction of the indentation (spaces vs. tabs) is unspecified. Tabs must be set exactly every 8 spaces (not 4).
http://peacepipe.toshiville.com/2006/05/vimrc-vim.html
set ts=8 sw=4 sts=4
も反しているとはいえない...
