How to change java version on the fly (in MacOS)

First, we need to install JEnv, we can do it through:

brew install jenv

In some cases, the user folders are not created during installation, we can make sure they are created:

mkdir ~/.jenv
mkdir ~/.jenv/versions

Now, we check which versions of Java are installed:

jenv versions

We enable the cask-versions of Homebrew, and we can access some older versions (in this case, Java 8):

brew tap homebrew/cask-versions
brew install --cask graalvm/tap/graalvm-ce-java8

Now, we add it to jenv

jenv add /Library/Java/JavaVirtualMachines/graalvm-ce-java8-21.0.0.2/Contents/Home

We set the global java version we want to use (we can also do this locally, per-project):

jenv global 1.8

For Maven to fetch the current jenv selected version we need to enable the plugin

jenv enable-plugin maven

Some times JEnv will not work without a reboot, we can issue this command to register it:

eval "$(jenv init -)"

Title here