With the relatively rapid change schedule for Java nowadays, I find it useful to have several versions of the JDK installed on my Mac so that I can easily switch between versions depending upon need.

I use the AdoptOpenJDK binaries and install them via HomeBrew.

Installation

To install via Homebrew, execute the following command (after installing HomeBrew itself which I'll not discuss here):

brew tap AdoptOpenJDK/openjdk
brew cask install <version>

Version can be one of:

• adoptopenjdk8
• adoptopenjdk9
• adoptopenjdk10
• adoptopenjdk11
• adoptopenjdk12
• adoptopenjdk13

In addition to these "standard" builds, you can install AdoptOpenJDK builds with the OpenJ9 JVM by adding the suffix -openj9, for example:

brew tap AdoptOpenJDK/openjdk
brew cask install adoptopenjdk13-openj9

You can get a full list of JDK and JRE versions that can be installed from the ( Project Page.

Selecting JDK Version

After installing the different versions of the JDK, you can easily add a zshrc (or bash) alias to allow a different version of the JDK to be selected. This can be achieved by running the following command to select a different Java version.

> echo 'alias java8="export JAVA_HOME=`/usr/libexec/java_home -v 1.8`; java -version"' >> ~/.zshrc
> echo 'alias java11="export JAVA_HOME=`/usr/libexec/java_home -v 11`; java -version"' >> ~/.zshrc

This example installs aliases for Java 8 and 11, but you can see how it would be easy to expand this for different versions of Java.

Credits

Photo by Tim Foster on Unsplash