Although this question was more specifically about IP addresses in Subject Alt. Names, the commands are similar (using DNS entries for a host name and IP entries for IP addresses).
To quote myself:
If you’re using
keytool, as of Java 7, keytool has an option to
include a Subject Alternative Name (see the table in the documentation
for -ext): you could use -ext san=dns:www.example.com or -ext
san=ip:10.0.0.1
Note that you only need Java 7’s keytool to use this command. Once you’ve prepared your keystore, it should work with previous versions of Java.
(The rest of this answer also mentions how to do this with OpenSSL, but it doesn’t seem to be what you’re using.)