"The commit occurs when the statement completes. The time when the statement completes depends on the type of SQL Statement: [...] For CallableStatement objects or for statements that return multiple results, the statement is complete when all of the associated result sets have been closed, and all update counts and output parameters have been retrieved."
Also, the spec says you should always turn off autocommit before batch updates, because the commit behavior in this case is implementation-defined.
Both of these points were raised the last time we discussed this on the list, but I didn't see a reply from you addressing them: http://archives.postgresql.org/pgsql-jdbc/2011-01/msg00055.php. Could you respond to the points in that post if you disagree?
Otherwise, I don't think it's very useful to rehash old issues as if they hadn't been discussed before.