You should be able to select the faster-but-slightly-less-secure /dev/urandom on Linux using:
-Djava.security.egd=file:/dev/urandom
However, this doesn’t work with Java 5 and later (Java Bug 6202721). The suggested work-around is to use:
-Djava.security.egd=file:/dev/./urandom
(note the extra /./
)