Install OpenJDK Version 12 on Mac

OpenJDK-Mac.md

OpenJDK on Mac

Follow these instructions to move from an Oracle JDK to OpenJDK. In a twist of irony, I had originally replaced OpenJDK on my Mac with the Oracle JDK!

Remove Oracle JDK

The steps for removing different versions of the JDK vary. This is what I did.

sudo rm -rf /Library/Internet\ Plug-Ins/JavaAppletPlugin.plugin
sudo rm -rf /Library/PreferencePanes/JavaControlPanel.prefPane
sudo rm -rf ~/Library/Application\ Support/Oracle/Java

Locate remaing JDKs.

$ ls /Library/Java/JavaVirtualMachines
jdk1.7.0_45.jdk   jdk1.7.0_71.jdk   jdk1.8.0_131.jdk   jdk1.8.0_45.jdk

Remove them too.

$ sudo rm -rf /Libary/Java/JavaVirtualMachines/jdk*

Verify

$ ls -l /usr/bin/java
lrwxr-xr-x  1 root  wheel   74 Oct  3  2018 /usr/bin/java -> /System/Library/Frameworks/JavaVM.framework/Versions/Current/Commands/Java

Install OpenJDK Versions 8, 9, and 10

brew tap AdoptOpenJDK/openjdk
brew search /adoptopenjdk/
brew cask install adoptopenjdk8

It may be possible to do it this way, but I didn't get it to work.

brew install adoptopenjdk/openjdk/adoptopenjdk-openjdk8

Install OpenJDK Version 12 (or Latest)

brew cask install adoptopenjdk

Install OpenJDK Version 11

brew cask install adoptopenjdk11

Set JAVA_HOME in ~/.bash_profile. E.g.

export JAVA_HOME=$(/usr/libexec/java_home)
echo $JAVA_HOME
/Library/Java/JavaVirtualMachines/adoptopenjdk-12.0.2.jdk/Contents/Home

A Note on Brew

I wanted to refresh my version of brew so I typed brew update.

References

1. How to uninstall JDK on Mac OS?
2. How do I uninstall Java on my Mac?
3. How do I remove the Java Deployment cache after Java is uninstalled?
4. Installing OpenJDK Versions on Macs
5. How to install OpenJDK 11 on Mac using brew
6. How do I update Homebrew?