Created on Dec 4, ’22 ・ Updated on Dec 4, ’22

jEnv

jEnv is a version manager for Java. It has, however, some limitations:

1. It does not provide the ability to install Java versions, this must be done using brew.
2. It will not update the JAVA_HOME. The export plugin must be enabled, but even then the JAVA_HOME will only be updated when the shell (re)starts.

Install jEnv

# install jenv
brew install jenv

# enable the export plugin
jenv enable-plugin export

# add these two lines in .zshrc
export PATH="$HOME/.jenv/bin:$PATH"
eval "$(jenv init -)"

Install Java versions

# for the latest java version
brew cask install adoptopenjdk

# for a specific version
# see https://github.com/AdoptOpenJDK/homebrew-openjdk
brew tap adoptopenjdk/openjdk
brew cask install adoptopenjdk8

Configure jEnv

# inform jenv of the installed java versions
jenv add /Library/Java/JavaVirtualMachines/adoptopenjdk-16.jdk/Contents/Home
jenv add /Library/Java/JavaVirtualMachines/adoptopenjdk-8.jdk/Contents/Home

jenv rehash

# verify
jenv versions

Change the Java version

# set the global version
jenv global 13.0

# set a local per-directory version
jenv local 1.8

# or a per-shell version
jenv shell 1.8

UI Applications

JAVA_HOME issue with UI apps: https://www.ibm.com/support/knowledgecenter/en/SSPJLC_7.6.2/com.ibm.si.mpl.doc/tshoot/ts_java_home.html

Misc

# to see if everything is ok, or not
jenv doctor

# list all commands
jenv commands

# help for a specific command
jenv help <command>

# to get a list of installed JVM
/usr/libexec/java_home -V