Copy/usr/libexec/java_home -V

lists one line per Java environment installed (and known to the /usr/bin/java command).

You can still have other Java distributions which are not registered. They are typically downloaded as ZIP files without an installer, or using another package manager like homebrew.

Mac OS X has a cool binary (/usr/libexec/java_home) that returns the path to a Java home directory from the current user's settings. You may want to issue:

Copy/usr/libexec/java_home -V

It prints the full JVM list with architectures like this:

CopyMatching Java Virtual Machines (2):
    13, x86_64: "OpenJDK 13"    /Library/Java/JavaVirtualMachines/openjdk-13.jdk/Contents/Home
    1.8.0_265, x86_64:  "AdoptOpenJDK 8"    /Library/Java/JavaVirtualMachines/adoptopenjdk-8.jdk/Contents/Home

/Library/Java/JavaVirtualMachines/openjdk-13.jdk/Contents/Home

If you want to print the JAVA_HOME path of a specific JDK version, you can do it like this:

Copy/usr/libexec/java_home -v 1.8
/Library/Java/JavaVirtualMachines/adoptopenjdk-8.jdk/Contents/Home

You can see the complete usage options of below:

CopyUsage: java_home [options...]
    Returns the path to a Java home directory from the current user's settings.

Options:
    [-v/--version   <version>]       Filter Java versions in the "JVMVersion" form 1.X(+ or *).
    [-a/--arch      <architecture>]  Filter JVMs matching architecture (i386, x86_64, etc).
    [-d/--datamodel <datamodel>]     Filter JVMs capable of -d32 or -d64
    [-t/--task      <task>]          Use the JVM list for a specific task (Applets, WebStart, BundledApp, JNI, or CommandLine)
    [-F/--failfast]                  Fail when filters return no JVMs, do not continue with default.
    [   --exec      <command> ...]   Execute the $JAVA_HOME/bin/<command> with the remaining arguments.
    [-R/--request]                   Request installation of a Java Runtime if not installed.
    [-X/--xml]                       Print full JVM list and additional data as XML plist.
    [-V/--verbose]                   Print full JVM list with architectures.
    [-h/--help]                      This usage information.

The cleanest way to manage multiple java versions on Mac is to use Homebrew.

And within Homebrew, use:

• homebrew-cask to install the versions of java
• jenv to manage the installed versions of java

As seen on http://hanxue-it.blogspot.ch/2014/05/installing-java-8-managing-multiple.html , these are the steps to follow.

1. install homebrew
2. install homebrew jenv
3. install homebrew-cask
4. install a specific java version using cask (see "homebrew-cask versions" paragraph below)
5. add this version for jenv to manage it
6. check the version is correctly managed by jenv
7. repeat steps 4 to 6 for each version of java you need

homebrew-cask versions

Add the homebrew/cask-versions tap to homebrew using:

Copybrew tap homebrew/cask-versions

Then you can look at all the versions available by searching for Eclipse temurin, more details here

Copybrew search temurin

Then you can install the version(s) you like, though version 7 no longer shows up in homebrew via these casks:

Copybrew install --cask temurin8
brew install --cask temurin9

And add them to be managed by jenv as usual.

Copyjenv add <javaVersionPathHere>

I think this is the cleanest & simplest way to go about it.

Another important thing to note, as mentioned in Mac OS X 10.6.7 Java Path Current JDK confusing :

For different types of JDKs or installations, you will have different paths

You can check the paths of the versions installed using /usr/libexec/java_home -V, see How do I check if the Java JDK is installed on Mac?

On Mac OS X Mavericks, I found as following:

1. Built-in JRE default: /Library/Internet\ Plug-Ins/JavaAppletPlugin.plugin/Contents/Home

2. JDKs downloaded from Apple: /System/Library/Java/JavaVirtualMachines/1.6.0.jdk/Contents/Home/

3. JDKs downloaded from Oracle: /Library/Java/JavaVirtualMachines/jdk1.8.0_11.jdk/Contents/Home

Resources

• Removing Java 8 JDK from Mac
• http://hanxue-it.blogspot.ch/2014/05/installing-java-8-managing-multiple.html
• http://sourabhbajaj.com/mac-setup/index.html
• http://brew.sh
• https://github.com/Homebrew/homebrew/tree/master/share/doc/homebrew#readme
• http://sourabhbajaj.com/mac-setup/Homebrew/README.html
• "brew tap” explained https://github.com/Homebrew/homebrew/blob/master/share/doc/homebrew/brew-tap.md
• “brew versions” explained Homebrew install specific version of formula? and also https://github.com/Homebrew/homebrew-versions
• https://github.com/caskroom/homebrew-cask
• “cask versions”, similar to “brew versions”, see https://github.com/caskroom/homebrew-versions and also https://github.com/caskroom/homebrew-cask/issues/9447
• http://www.jenv.be
• https://github.com/gcuisinier/jenv