Experimenting with jdk8

Debian linux

If you are on any variant of Debian linux, there is the convenience of being able to set alternative java using update alternatives:-

su -c "update-alternatives --config java"

Output

There are 3 choices for the alternative java (providing /usr/bin/java).

  Selection    Path                                            Priority   Status
------------------------------------------------------------
  0            /usr/lib/jvm/java-7-openjdk-amd64/jre/bin/java   1071      auto mode
  1            /opt/jdk1.7.0_51/bin/java                        100       manual mode
* 2            /opt/jdk1.8.0/bin/java                           100       manual mode
  3            /usr/lib/jvm/java-7-openjdk-amd64/jre/bin/java   1071      manual mode

Press enter to keep the current choice[*], or type selection number: 

Other linux

Tools/Configuration

How do I check which version of the JVM JRuby is running on?

jruby -rjava -e "puts java.lang.System.get_property('java.version')"

prints out 1.8.0 with above setup.