JDBC with PG 8.4 bytea character escaping wire protocol

Does the JDBC 4 driver for PG 8.4 escape each character of the bytea
type, or does it use a binary protocol?

 From another post, Merlin Moncure wrote, "libpq supports a binary
protocol mode which allows you to execute queries sending bytea without
escaping."  Is that true of the JDBC driver?  I'm concerned about the
data size expansion that would result for the wire protocol when I use
setBytes().

Thanks,
David