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Wilson Mar

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Overview

Like a long tour with commentary by an experienced guide, this is a deep dive into the various editions to equip you to debug JVM installation issues. “PROTIP” mark little-know or important facts not seen in many other tutorials.

There are several ways to install Java.

Which Java You Got?

You’ll come back to this after installation.

  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:

    /usr/bin/java

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

  3. List which versions are installed on your machine by looking at where MacOS installs programs:

    ls -al /Library/Java/JavaVirtualMachines/
    

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

    The response on my machine, after all versions of Java are installed (at time of writing):

    total 0
    drwxr-xr-x   6 root  wheel  192 Jul 24 11:13 .
    drwxr-xr-x   5 root  wheel  160 Nov 18  2018 ..
    drwxr-xr-x   3 root  wheel   96 Mar 30  2018 jdk1.8.0_162.jdk
    drwxr-xr-x   3 root  wheel   96 Feb  9  2019 jdk1.8.0_202.jdk
    drwxr-xr-x   3 root  wheel   96 Jul 24 11:13 zulu-16.jdk
    drwxr-xr-x  18 root  wheel  576 Nov 18  2018 zulu8.30.0.1-jdk8.0.172-macosx_x64
    

    WARNING: Older versions may not contain the latest security patches.

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

    echo $JAVA_HOME

    Sample response:

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

    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 many others.

  5. Additional details are provided by 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
     
    /Library/Java/JavaVirtualMachines/adoptopenjdk-8.jdk/Contents/Home
    

    Alternately:

    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
     
    /Library/Java/JavaVirtualMachines/jdk1.8.0_45.jdk/Contents/Home
    
  6. PROTIP: It’s kinda ironic, but to see what Java VM you have already installed, it helps if you know what version you have.

    Java 8 and before uses a non-standard parameter. Most other programs use either the -v flag or two-dash --version with the longer-form parameter name. However, with Java:

    java -version
    

    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)
    

    Alternately, Java 9 and after uses the standard “–version” (with two dashes) like most other Java programs:

    java --version
    
  7. PROTIP: Java 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
    

    I’ll stay with version 8 then

    Like many other open source advocates, we continue to use version 8 even though more recent versions have been created by Oracle.

    This is because Oracle changed their licensing after version 8 in 2017.

    PROTIP: Many prefer to use Java 8 because it is the last version which is free open-source licensed.

    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.

    Oracle’s versions are described at http://www.oracle.com/technetwork/java/javase/downloads/index.html

    Oracles docs on installing the JDK:
    https://docs.oracle.com/javase/8/docs/technotes/guides/install/mac_jdk.html

    NOTE: Downloads of the JDK (Java Development Kit) contains the JRE (Java Runtime Engine).

  8. PROTIP: Install not the latest 64-bit Java Development Kit (JDK), but the last stable v1.8 version:

    brew tap caskroom/versions
    brew install --cask java8
    

    The response:

    ==> Caveats
    This Cask makes minor modifications to the JRE to prevent issues with
    packaged applications, as discussed here:
     
      https://bugs.eclipse.org/bugs/show_bug.cgi?id=411361
     
    If your Java application still asks for JRE installation, you might need
    to reboot or logout/login.
     
    Installing this Cask means you have AGREED to the Oracle Binary Code
    License Agreement for Java SE at
     
      https://www.oracle.com/technetwork/java/javase/terms/license/index.html
     
    ==> Satisfying dependencies
    ==> Downloading http://download.oracle.com/otn-pub/java/jdk/8u152-b16/aa0333dd30
    ######################################################################## 100.0%
    ==> Verifying checksum for Cask java8
    ==> Installing Cask java8
    ==> Running installer for java8; your password may be necessary.
    ==> Package installers may write to any location; options such as --appdir are i
    Password:
    ==> installer: Package name is JDK 8 Update 152
    ==> installer: Installing at base path /
    ==> installer: The install was successful.
    🍺  java8 was successfully installed!
    

    Apple Java obsoleted

    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, re-install Java 6 for OS X 2014-001 obtained from https://support.apple.com/kb/DL1572?locale=en_US

    Different Javas available

    https://www.wikiwand.com/en/List_of_Java_virtual_machines lists all 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

    Zulu

    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 search zulu

    The response:

    ==> Formulae
    zurl
    ==> Casks
    zulu       zulu11     zulu13     zulu15     zulu7      zulu8      zulufx
    
  9. To install the latest:

    brew install zulu

    The response:

    ==> Downloading https://cdn.azul.com/zulu/bin/zulu16.30.15-ca-jdk16.0.1-macosx_x
    ######################################################################## 100.0%
    ==> Installing Cask zulu
    ==> Running installer for zulu; your password may be necessary.
    Package installers may write to any location; options such as `--appdir` are ignored.
    installer: Package name is Zulu 16.30+15
    installer: Installing at base path /
    installer: The install was successful.
    

Install Jenv to manage multiple Versions of Java

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

http://hanxue-it.blogspot.com/2014/05/installing-java-8-managing-multiple.html?q=java
describes the steps.

  1. Consider the Jenv utility:

    brew info jenv

    The response at time of writing:

    jenv: stable 0.5.4 (bottled), HEAD
    Manage your Java environment
    https://www.jenv.be/
    Not installed
    From: https://github.com/Homebrew/homebrew-core/blob/HEAD/Formula/jenv.rb
    License: MIT
    ==> Options
    --HEAD
    Install HEAD version
    ==> Caveats
    To activate jenv, add the following to your /Users/wilsonmar/.bash_profile:
      export PATH="$HOME/.jenv/bin:$PATH"
      eval "$(jenv init -)"
    ==> Analytics
    install: 9,034 (30 days), 28,364 (90 days), 124,693 (365 days)
    install-on-request: 9,030 (30 days), 28,348 (90 days), 124,090 (365 days)
    build-error: 0 (30 days)
    
  2. Install Jenv by specifying the location URL: https://raw.githubusercontent.com/entrypass/jenv/homebrew/homebrew/jenv.rb

    brew install jenv

    The response:

    ...
    ==> Caveats
    To activate jenv, add the following to your /Users/wilsonmar/.bash_profile:
      export PATH="$HOME/.jenv/bin:$PATH"
      eval "$(jenv init -)"
    ==> Summary
    🍺  /usr/local/Cellar/jenv/0.5.4: 84 files, 73KB
    

    Previously:

    🍺  /usr/local/Cellar/jenv/0.4.4: 78 files, 65.5KB, built in 8 seconds
    
  3. Instead of editing ~/.bash_profile as described above, paste this which handles errors better:

    export JENV_ROOT="$(which jenv)" # /usr/local/var/jenv
    if command -v jyenv 1>/dev/null 2>&1; then
      eval "$(jenv init -)"
    fi
    
  4. Restart:

    source ~/.bash_profile

  5. To see if jenv can run, list its version and commands:

    jenv

    The response is like this (at time of writing July 24, 2021):

    jenv 0.5.4
    Usage: jenv <command> [<args>]
     
    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
    add         Add JDK into jenv. A alias name will be generated by parsing "java -version"
     
    See `jenv help ' for information on a specific command.
    For full documentation, see: https://github.com/hikage/jenv#readme
    
  6. See where the symlink leads:

    ls -al $(which jenv)

    My response (at time of writing):

    lrwxr-xr-x  1 wilsonmar  admin  29 Jul 24 10:10 /usr/local/bin/jenv -> ../Cellar/jenv/0.5.4/bin/jenv

    NOTE: The file jenv is a binary executable.

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

    export JENV_ROOT=”$(which jenv)” echo “$JENV_ROOT”

    Jenv for several Java versions

  8. Get info:

    jenv info java
    

    Sample response:

    Jenv will exec : /usr/bin/java
    Exported variables :
      JAVA_HOME=/usr/local/bin/jenv/versions/system
    
  9. List installers available for use by jenv:

    ls -al /Library/Java/JavaVirtualMachines/
    

    The response:

    total 0
    drwxr-xr-x   6 root  wheel  192 Jul 24 11:13 .
    drwxr-xr-x   5 root  wheel  160 Nov 18  2018 ..
    drwxr-xr-x   3 root  wheel   96 Mar 30  2018 jdk1.8.0_162.jdk
    drwxr-xr-x   3 root  wheel   96 Feb  9  2019 jdk1.8.0_202.jdk
    drwxr-xr-x   3 root  wheel   96 Jul 24 11:13 zulu-16.jdk
    drwxr-xr-x  18 root  wheel  576 Nov 18  2018 zulu8.30.0.1-jdk8.0.172-macosx_x64
    

    The folders above provide version handles (such as “zulu-16.jdk”) for jenv to reference.

    For each version, along with lib and man (manual) folders, Jenv looks into a bin folder containing executables to use.

  10. Construct the a path to those folder for a version by adding folder /Contents/Home to the known path:

    FOLDER="/Library/Java/JavaVirtualMachines/zulu-16.jdk/Contents/Home"
    ls "$FOLDER"
    

    The response:

    DISCLAIMER   bin          demo         jmods        lib          readme.txt
    Welcome.html conf         include      legal        man          release
    

    Add Java versions

  11. Construct a command to the path by adding”/Contents/Home” to the path you already know, such as this:

    jenv add "$FOLDER"
    

    A sample response:

    zulu-16.jdk added
    
  12. 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)
    
  13. To configure global version for all apps to use:

    jenv global oracle64-1.8.0.45
    

    Example response:

    system
    oracle64-1.7.0.65
    * oracle64-1.8.0.45 (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

    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

https://java.com/en/download/help/mac_java_update.xml

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 3.8.1 (05c21c65bdfed0f71a2f2ada8b84da59348c4c5d)
    Maven home: /usr/local/Cellar/maven/3.8.1/libexec
    Java version: 1.8.0_162, vendor: Oracle Corporation, runtime: /Library/Java/JavaVirtualMachines/jdk1.8.0_162.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

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

Social

Top Java Blogs/bloggers to follow on Twitter:

More on macOS

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