With the increasing number of JDK builds and the more frequent release candence, I found it hard to keep track what I had installed in my MacOS and switch between them on the fly.

Even in 2019 my preferred version of Java is 1.8, probably because this is the version I am using at my work. But depending on the occasion I find myself experimenting with newer features from later versions, or even from experimental builds:

• JShell from Java 9 onwards
• EpsilonGC
• The use of var since Java 10
• Value types in Project Valhalla builds
• etc…

In addition, nowadays on my personal computer I mainly use Java builds from the AdoptOpenJDK project. But there are other builds which I have installed on my MacOS to try out:

• GraalVM
• Zulu
• Coretto

Hence I spent some putting together some bash functions that give me a hand managing and switching between those versions.

For the complete bash script see here, but the highlights are:

• List JKDs

• List Different JDK builds

• Set JDK to a specific version/vendor

Note that java_home=/usr/libexec/java_home