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Wilson Mar


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There are several ways to install Java. This is a deep dive into the various editions to equip you to debug JVM installation issues.

Which Java You Got?

  1. Open a Terminal session.

  2. Shell scripts check if Java is available by:

    command -v java

    Alternately, the older form is:

    which java

    Either way, the response:


    PROTIP: File “java” in the above path is a binary file.

  3. To see what Java VM you have already installed:

    /usr/bin/java -version

    PROTIP: -version is a non-standard parameter. Most other programs use either the -v flag or two-dash --version with the longer-form parameter name.

    A sample response:

    java version "1.8.0_162"
    Java(TM) SE Runtime Environment (build 1.8.0_162-b12)
    Java HotSpot(TM) 64-Bit Server VM (build 25.162-b12, mixed mode)
  4. List which versions are installed on your machine:

    ls /Library/Java/JavaVirtualMachines/

    PROTIP: On Macs, all known JVM’s are located at:

    NOTE: This directory is at the root for the whole machine, not a particular user’s home folder.

    The response on my machine:

  5. PROTIP: The Java program looks for the $JAVA_HOME environment variable to obtain files:

    echo $JAVA_HOME

    Sample response:


    PROTIP: This command is my preferred way to see what a machine has because if you invoke java or javac, if it’s not installed, MacOS prompts you to install the JDK. Clever. But don’t do it if you want other version of Java.

    Java is used by Groovy, Grails, Spring Boot, and others.

  6. PROTIP: Developers use the JDK rather than the JRE (Runtime Environment) in order to get the javac compiler. See what version of the Java Compiler is installed:

    javac -version

    A sample response:

    javac 1.8.0_162
  7. Additional details are provided with this command:

    /usr/libexec/java_home -V

    That’s a capital -V.

    The response on my machine:

    Matching Java Virtual Machines (1):
     1.8.0_232, x86_64:	"AdoptOpenJDK 8"	/Library/Java/JavaVirtualMachines/adoptopenjdk-8.jdk/Contents/Home


    Matching Java Virtual Machines (4):
    1.8.0_45, x86_64:	"Java SE 8"	/Library/Java/JavaVirtualMachines/jdk1.8.0_45.jdk/Contents/Home
    1.7.0_65, x86_64:	"Java SE 7"	/Library/Java/JavaVirtualMachines/jdk1.7.0_65.jdk/Contents/Home
    1.6.0_65-b14-466.1, x86_64:	"Java SE 6"	/System/Library/Java/JavaVirtualMachines/1.6.0.jdk/Contents/Home
    1.6.0_65-b14-466.1, i386:	"Java SE 6"	/System/Library/Java/JavaVirtualMachines/1.6.0.jdk/Contents/Home

    Apple Java

    PROTIP: The version that comes installed on Apple Macs is obsolete and thus does not have the latest security patches. But do NOT delete the default version.

    But if you did uninstall it, to re-install Java 6 for OS X 2014-001, it can be obtained from https://support.apple.com/kb/DL1572?locale=en_US

    Different Javas

    https://en.wikipedia.org/wiki/List_of_Java_virtual_machines lists all the known Java compilers. Several organizations work on OpenSDK specs from AdoptOpenJDK and certified for Java SE TCK compliance on x64 reference architecture systems

    • When Oracle acquired Sun, the jdk (Java Development Kit) was one of the products obtained. Versions are downloaded directly from Oracle from http://jdk.java.net.

    • https://adoptopenjdk.net/ has both 8, 11, and 13 running the tradition “HotSpot” JVM and the more recent and faster “OpenJ9” JVM. To install the latest (v13):

    brew install --cask adoptopenjdk
    • Azul Zulu downloads for macOS, from a company that also sells Java optimization products. Its zulu8.30.0.1-jdk8.0.172-macosx_x64 from zip April 18, 2018 is 179.2 MB expanded
    brew cask search zulu

    Latest Version of Oracle Java

  8. PROTIP: Hold off downloading the java .dmg installer file as described at https://java.com/en/download/help/mac_install.xml

    WARNING: Oracle installs an annoying Ask Toolbar, without asking.

    Oracles docs on installing the JDK:

  9. Use an internet browser to

  10. Click the “Download” button for the JDK (not the JRE).

    NOTE: Downloads of the JDK contains the JRE.

Install Jenv to manage multiple Versions of Java

PROTIP: If you’re a developer, you’ll likely need to manage different versions of Java needed by different apps. Much like NPM for Node and rbenv for Ruby.

describes the steps.

  1. Install Jenv by specifying the location URL: https://raw.githubusercontent.com/entrypass/jenv/homebrew/homebrew/jenv.rb

    brew install jenv

    The response:

    ==> Downloading https://github.com/gcuisinier/jenv/archive/0.4.4.tar.gz
    ==> Downloading from https://codeload.github.com/gcuisinier/jenv/tar.gz/0.4.4
    ######################################################################## 100.0%
    🍺  /usr/local/Cellar/jenv/0.4.4: 78 files, 65.5KB, built in 8 seconds
  2. To see if jenv can run, list its version and commands:


    The response is like this (at time of writing Oct 15, 2018):

    jenv 0.4.4
    Usage: jenv  []
    Some useful jenv commands are:
    commands    List all available jenv commands
    local       Set or show the local application-specific Java version
    global      Set or show the global Java version
    shell       Set or show the shell-specific Java version
    rehash      Rehash jenv shims (run this after installing executables)
    version     Show the current Java version and its origin
    versions    List all Java versions available to jenv
    which       Display the full path to an executable
    whence      List all Java versions that contain the given executable
    See `jenv help ' for information on a specific command.
    For full documentation, see: https://github.com/hikage/jenv#readme
  3. See where it was installed:

    which jenv

    My response:


    NOTE: The file jenv is a binary executable.

  4. Use Homebrew’s directories rather than ~/.jenv add to the bottom of your bash_profile file:

    export JENV_ROOT=/usr/local/var/jenv

  5. To enable shims and autocompletion add to the botton of your bash_profile file:

    if which jenv > /dev/null; then eval "$(jenv init -)"; fi

    Jenv for several Java versions

  6. Get info:

    jenv info java

    Sample response:

    Jenv will exec : /usr/bin/java
    Exported variables :
  7. List installers available for use by jenv:

    ls -al /Library/Java/JavaVirtualMachines/

    The response:

    total 0
    drwxr-xr-x  5 root  wheel  160 Mar 30  2018 .
    drwxr-xr-x  5 root  wheel  160 Mar 30  2018 ..
    drwxr-xr-x  2 root  wheel   64 Mar 30  2018 jdk-10.jdk
    drwxr-xr-x  2 root  wheel   64 Mar 30  2018 jdk1.8.0_144.jdk
    drwxr-xr-x  3 root  wheel   96 Mar 30  2018 jdk1.8.0_162.jdk

    If you don’t see any, you need to first download a JVM installer containing folders bin, lib, jre, include, bundle, db, man.

    The path to a particular version is constructed by adding “/Contents/Home” to the end of the path.

  8. The point of jenv is to add additional versions, such as back version JDK 7.

    jenv add /Library/Java/JavaVirtualMachines/jdk1.7.0_65.jdk/Contents/Home

    The response:

    oracle64- added
  9. Add JDK 8:

    jenv add /Library/Java/JavaVirtualMachines/jdk1.8.0_162.jdk/Contents/Home


    The response:

    oracle64- added

    The above provide a handle for jenv provide other apps to use.

  10. List the Java versions jenv knows about:

    jenv versions

    The response if none if brew cask was not installed:

    * system (set by /usr/local/var/jenv/version)
  11. To configure global version for all apps to use:

    jenv global oracle64-

    Example response:

    * oracle64- (set by /Users/wilsonmar/.jenv/version)

Open JDK

Open JDK is the open-sourced implementation of the JRE spec, at http://openjdk.java.net

But some say it is not ready for “prime time” on MacOS because its installation is a dirty affair from 2013 when going from v6 to v7:

  • https://wiki.openjdk.java.net/display/MacOSXPort/Mac+OS+X+Port+Project+Status

Open JDK’s install page at http://openjdk.java.net/install/ shows apt-get (for Debian, Ubuntu) and yum (for Red Hat, CentOS, Oracle Linus, Fedora).

  • http://blog.shelan.org/2015/03/how-to-build-open-jdk-9-on-mac-osx.html on Yosemite

  • http://hanxue-it.blogspot.com/2014/05/installing-java-8-managing-multiple.html

For macOS, this page recommends using Make to compile from source.

  1. Download source using Mercurial to a new folder “openjdk9”:

    hg clone http://hg.openjdk.java.net/jdk9/jdk9 openjdk9 cd ./openjdk9

    Note JDK 9 is under active development.

    http://hg.openjdk.java.net/jdk8/jdk8 work stopped at 2014-03-04.

  2. Install XQuartz for X Window System that runs on Macs:

    brew install Caskroom/cask/xquartz
    brew cask list

    NOTE: Downloaded /Library/Caches/Homebrew/xquartz-2.7.9.dmg was 7.9K

    xquartz staged at ‘/opt/homebrew-cask/Caskroom/xquartz/2.7.9’ (73M)

  3. cd to the .tar.gz directory containing the configure file for Make to use.
  4. XQuartz fixes an error in this command:

    bash ./configure

  5. Install apple-gcc42 the Apple C compiler.

    Mihail recommends:

  6. Install ccache (compiler cache):

    brew install ccache

  7. Make a symlink /usr/bin/gcc -> /usr/local/Cellar/apple-gcc42/4.2.1-5666.3/bin/gcc-4.2 (same for g++)

Test JDK Build

https://mihail.stoynov.com/2015/01/29/building-openjdk-9-on-a-osx-or-any-linux/ shows JDK 9 install using ccache, mercurial (hg), jtreg “testing harness”, and Webrev to diff code

Update Java


NOTE: Others include cheatsheet, google-chrome, google-drive, google-hangouts, dropbox, etc. listed in Sourabh Bajaj’s venerable Mac OSX Setup Guide, developed and distributed as a GitBook.

Maven (mvn)

  1. Install using Homebrew:

    brew install maven
  2. See its metadata and what java version Maven is based on:

    mvn -version

    If it’s installed, the sample response:

    Apache Maven 3.6.3 (cecedd343002696d0abb50b32b541b8a6ba2883f)
    Maven home: /usr/local/Cellar/maven/3.6.3/libexec
    Java version: 1.8.0_232, vendor: AdoptOpenJDK, runtime: /Library/Java/JavaVirtualMachines/adoptopenjdk-8.jdk/Contents/Home/jre
    Default locale: en_US, platform encoding: UTF-8
    OS name: "mac os x", version: "10.14.6", arch: "x86_64", family: "mac"

    PROTIP: Many have switched to using Gradle instead of Maven or Ant.


Kotlin is a language that makes use of the JVM. Invented by JetBrains (IntelliJ).


Top Java Blogs/bloggers to follow on Twitter:

More on macOS

This is one of a series about macOS (previously Mac OSX):