Before installing this JRE, you have to install the linux binary compatibility on FreeBSD, you can follow this documentation. Jave requires some information about the proc. You have to mount linprocfs, type:
kldload linprocfs
mount -t linprocfs linprocfs /compat/linux/proc
and add this line to /etc/fstab:
linprocfs /compat/linux/proc linprocfs rw 0 0