See 'air-dex' example on this post: http://askubuntu.com/questions/159575/how-do-i-make-java-default-to-a-manually-installed-jre-jdk . Note: sometimes people install Java JDK's into '/usr/lib/jvm', and as you can see in the output on my blog post, the system came with default JVMs in this location, but personally I don't recommend that for a JDK. Maybe I would choose '/usr/lib/jvm' if it was a JRE I was installing. If you wanted an alternative location for JDKs and JREs, I would choose either:
1. /usr/java/ 2. /opt/java/ If I were comparing to windows, I might say:
JDKs: /usr/java = C:\Java JREs: /usr/lib/jvm = C:\Program Files\Java Alt: /opt/java = E:\Java