How do I install multiple versions of Java on Ubuntu?

To switch between installed java versions, use the update-java-alternatives command. … where /path/to/java/version is one of those listed by the previous command (e.g. /usr/lib/jvm/java-7-openjdk-amd64 ).

Can I have 2 Java versions installed?

It is very possible to run multiple versions of Java on the same machine so you can run your existing applications and Ignition at the same time.