I want to install OpenJDK Java 11 on Mac OSX and have it work alongside other JDK's since it is a newer release. Currently, I downloaded the tar.gz and placed it in my path but that is hard to maintain.

The only other installs I found that do more things automatically are the Oracle install via Homebrew cask, but that is the commercial JDK and I want the open-source one!

brew cask info java

Shows:

java: 11,28:55eed80b163941c8885ad9298e6d786a
https://www.oracle.com/technetwork/java/javase/overview/index.html

Which it is the Oracle JDK and not OpenJDK, see:
https://discourse.brew.sh/t/how-to-install-openjdk-with-brew/712

Following directions from an older question (Mac OS X and multiple Java versions) is outdated and gives me the wrong version -- Oracle not OpenJDK.

Update: As of October 3, 2018 the Homebrew cask is now pointing to OpenJDK 11

note: These solutions work for your specific case of Java 11 OpenJDK but also work for any other previous Java version covered by the listed version managers. This includes alternative JDK's from OpenJDK, Oracle, IBM, Azul, Amazon Correto, Graal and more. Easily work with Java 7, Java 8, Java 9, Java 10, Java 11, and even early access Java 12!

You have a few options of how to do the installation as well as manage JDK switching. Installation can be done by Homebrew, SDKMAN, Jabba, or a manual install. Switching can be done by JEnv, SDKMAN, Jabba, or manually by setting JAVA_HOME. All of these are described below.

Installation

First, install Java using whatever method you prefer including Homebrew, SDKMAN or a manual install of the tar.gz file. The advantages of a manual install is that the location of the JDK can be placed in a standardized location for Mac OSX.

Install with SDKMAN

This is a simple model in that it handles both installation and version switching, with a caveat that it installs the JDK into a non-standard directory.

<see below "Installing and Switching versions with SDKMAN">

Install using Jabba

This is also a simple model in that both installation and version switching are handled by the same tool. The installations are made to a non-standard directory.

<see below "Installing and Switching versions with Jabba">

Install manually from OpenJDK download page:

1. Download OpenJDK 11 for Mac OSX from http://jdk.java.net/11/ (or early access JDK 12 from http://jdk.java.net/12/)




2. Unarchive the OpenJDK tar, and place the resulting jdk-11.jdk folder into your /Library/Java/JavaVirtualMachines/ folder since this is the standard and expected location of JDK installs. You can also install anywhere you want in reality.

Install with Homebrew

The version of Java available in Homebrew Cask previos to October 3, 2018 was indeed the Oracle JVM. Now however, it has now been updated to OpenJDK. Be sure to update Homebrew and then you will see the lastest version available for install.

1. 
   

   install Homebrew if you haven't already. Make sure it is updated:

   
   
   

   brew update
   
   

   
   


2. 
   

   Add the casks tap, if you haven't already:

   
   
   

   brew tap homebrew/cask-versions
   
   

   
   


3. 
   

   Look for installable versions:

   
   
   

   brew search java
   
   

   
   


4. 
   

   Check the details on the version that will be installed:

   
   
   

   brew cask info java
   
   

   
   
   

   Note: prior to October 3, 2018 that the current release is the Oracle commercial version of Java 11, and after October 3 this is now OpenJDK 11.

   
   


5. 
   

   Install a specific version of the JDK such as java8, java10 or java for the current:

   
   
   

   brew cask install java
   
   

   
   
   

   The AdoptOpenJDK version is available as well now from Homebrew Cask:

   
   
   

   brew cask install adoptopenjdk
   
   

   
   

And these will be installed into /Library/Java/JavaVirtualMachines/ which is the traditional location expected on Mac OSX.

Other installation options:

Some other flavours of openJDK are:

Azul Systems Java Zulu certified builds of OpenJDK can be installed by following the instructions on their site.

Zulu® is a certified build of OpenJDK that is fully compliant with the Java SE standard. Zulu is 100% open source and freely downloadable. Now Java developers, system administrators, and end users can enjoy the full benefits of open source Java with deployment flexibility and control over upgrade timing.

Amazon Correto OpenJDK builds have an easy to use installation package for version 8 (other versions are coming), and installs to the standard /Library/Java/JavaVirtualMachines/ directory on Mac OSX.

Amazon Corretto is a no-cost, multiplatform, production-ready distribution of the Open Java Development Kit (OpenJDK). Corretto comes with long-term support that will include performance enhancements and security fixes. Amazon runs Corretto internally on thousands of production services and Corretto is certified as compatible with the Java SE standard. With Corretto, you can develop and run Java applications on popular operating systems, including Amazon Linux 2, Windows, and macOS.

Where is my JDK?!?!

To find locations of previously installed Java JDK's installed at the default system locations, use:

/usr/libexec/java_home -V

Matching Java Virtual Machines (8):
11, x86_64: "Java SE 11" /Library/Java/JavaVirtualMachines/jdk-11.jdk/Contents/Home
10.0.2, x86_64: "Java SE 10.0.2" /Library/Java/JavaVirtualMachines/jdk-10.0.2.jdk/Contents/Home
9, x86_64: "Java SE 9" /Library/Java/JavaVirtualMachines/jdk-9.jdk/Contents/Home
1.8.0_144, x86_64: "Java SE 8" /Library/Java/JavaVirtualMachines/jdk1.8.0_144.jdk/Contents/Home

You can also report just the location of a specific Java version using -v

/usr/libexec/java_home -v 11

/Library/Java/JavaVirtualMachines/jdk-11.jdk/Contents/Home

Knowing the location of the installed JDK's is also useful when using tools like JEnv, or adding a local install to SDKMAN, or linking a system JDK in Jabba -- and you need to know where to find them.

If you need to find JDK's instaled by other tools, check these locations:

• SDKMAN installs to ~/.sdkman/candidates/java/
  


• Jabba installs to ~/.jabba/jdk

Switching versions manually

The Java executable is a wrapper that will use whatever JDK is configured in JAVA_HOME, so you can change that to also change which JDK is in use.

For example, if you installed or untar'd JDK 11 to /Library/Java/JavaVirtualMachines/jdk-11.jdk if it is the highest version number it should already be the default, if not you could simply set:

export JAVA_HOME=/Library/Java/JavaVirtualMachines/jdk-11.jdk/Contents/Home

And now whatever Java executable is in the path will see this and use the correct JDK.

Using the /usr/libexec/java_home utility as previously described helps you to create aliases or to run commands to change Java versions by identifying the locations of different JDK installations. For example, creating shell aliases in your .profile or .bash_profile to change JAVA_HOME for you:

export JAVA_8_HOME=$(/usr/libexec/java_home -v1.8)

export JAVA_9_HOME=$(/usr/libexec/java_home -v9)

export JAVA_10_HOME=$(/usr/libexec/java_home -v10)

export JAVA_11_HOME=$(/usr/libexec/java_home -v11)



alias java8='export JAVA_HOME=$JAVA_8_HOME'

alias java9='export JAVA_HOME=$JAVA_9_HOME'

alias java10='export JAVA_HOME=$JAVA_10_HOME'

alias java11='export JAVA_HOME=$JAVA_11_HOME'



# default to Java 11

java11

Then to change versions, just use the alias.

java8

java -version

java version "1.8.0_144"

Of course setting JAVA_HOME manually works too!

Switching versions with JEnv

JEnv expects the Java JDK's to already exist on the machine and can be in any location. Typically you will find installed Java JDK's in /Library/Java/JavaVirtualMachines/. JEnv allows setting the global version of Java, one for the current shell, and a per-directory local version which is handy when some projects require different versions than others.

1. Install JEnv if you haven't already, instructions on the site http://www.jenv.be/ for manual install or using Homebrew.



2. 
   

   Add any Java version to JEnv (adjust the directory if you placed this elsewhere):

   
   
   

   jenv add /Library/Java/JavaVirtualMachines/jdk-11.jdk/Contents/Home
   
   

   
   


3. 
   

   Set your global version using this command:

   
   
   

   jenv global 11
   
   

   
   

You can also add other existing versions using jenv add in a similar manner, and list those that are available. For example Java 8:

jenv add /Library/Java/JavaVirtualMachines/jdk1.8.0_144.jdk/Contents/Home 

jenv versions

See the JEnv docs for more commands. You may now switch between any Java versions (Oracle, OpenJDK, other) at any time either for the whole system, for shells, or per local directory.

To help manage JAVA_HOME while using JEnv you can add the export plugin to do this for you.

$ jenv enable-plugin export

  You may restart your session to activate jenv export plugin echo export plugin activated

The export plugin may not adjust JAVA_HOME if it is already set, so you may need to clear this variable in your profile so that it can be managed by JEnv.

You can also use jenv exec <command> <parms...> to run single commands with JAVA_HOME and PATH set correctly for that one command, which could include opening another shell.

Installing and Switching versions with SDKMAN

SDKMAN is a bit different and handles both the install and the switching. SDKMAN also places the installed JDK's into its own directory tree, which is typically ~/.sdkman/candidates/java. SDKMAN allows setting a global default version, and a version specific to the current shell.

1. Install SDKMAN from https://sdkman.io/install



2. 
   

   Install Java 11 using SDKMAN:

   
   
   

   sdk install java 11.0.0-open 
   
   

   
   


3. 
   

   Make 11 the default version:

   
   
   

   sdk default java 11.0.0-open
   
   

   
   
   

   Or switch to 11 for the session:

   
   
   

   sdk use java 11.0.0-open
   
   

   
   

You can list available versions for installation using the list command:

sdk list java

And install additional versions, such as JDK 8:

sdk install java 8.0.181-oracle

SDKMAN can work with previously installed existing versions. Just do a local install giving your own version label and the location of the JDK:

sdk install java my-local-11 /Library/Java/JavaVirtualMachines/jdk-11.jdk/Contents/Home

And use it freely:

sdk use java my-local-11

More information is available in the SDKMAN Usage Guide along with other SDK's it can install and manage.

SDKMAN will automatically manage your PATH and JAVA_HOME for you as you change versions.

Installing and Switching versions with Jabba

Jabba also handles both the install and the switching. Jabba also places the installed JDK's into its own directory tree, which is typically ~/.jabba/jdk.

1. Install Jabba by following the instructions on the home page.



2. 
   

   List available JDK's

   
   
   

   jabba ls-remote
   
   

   
   


3. 
   

   Install Java JDK 11

   
   
   

   jabba install openjdk@1.11.0
   
   

   
   


4. 
   

   Use it:

   
   
   

   jabba use openjdk@1.11.0
   
   

   
   

You can also alias version names, link to existing JDK's already installed, and find a mix of interesting JDK's such as GraalVM, Adopt JDK, IBM JDK, and more. The complete usage guide is available on the home page as well.

Jabba will automatically manage your PATH and JAVA_HOME for you as you change versions.

Manually switching system-default version without 3rd party tools:

As detailed in this older answer, on macOS /usr/bin/java is a wrapper tool that will use Java version pointed by JAVA_HOME or if that variable is not set will look for Java installations under /Library/Java/JavaVirtualMachines/ and will use the one with highest version. It determines versions by looking at Contents/Info.plist under each package.

Armed with this knowledge you can:

• control which version the system will use by renaming Info.plist in versions you don't want to use as default (that file is not used by the actual Java runtime itself).


• control which version to use for specific tasks by setting $JAVA_HOME
  

I've just verified this is still true with OpenJDK & Mojave.

On a brand new system, there is no Java version installed:

$ java -version

No Java runtime present, requesting install.

Cancel this, download OpenJDK 11 & 12ea on https://jdk.java.net ;
install OpenJDK11:

$ cd /Library/Java/JavaVirtualMachines/

$ sudo tar xzf ~/Downloads/openjdk-11.0.1_osx-x64_bin.tar.gz

System java is now 11:

$ java -version

openjdk version "11.0.1" 2018-10-16

[...]

Install OpenJDK12 (early access at the moment):

$ sudo tar xzf ~/Downloads/openjdk-12-ea+17_osx-x64_bin.tar.gz 

System java is now 12:

$ java -version

openjdk version "12-ea" 2019-03-19

[...]

Now let's "hide" OpenJDK 12 from system java wrapper:

$ cd jdk-12.jdk/Contents/

$ sudo mv Info.plist Info.plist.disabled

System java is back to 11:

$ java -version

openjdk version "11.0.1" 2018-10-16

[...]

And you can still use version 12 punctually by manually setting JAVA_HOME:

$ export JAVA_HOME=/Library/Java/JavaVirtualMachines/jdk-12.jdk/Contents/Home

$ java -version

openjdk version "12-ea" 2019-03-19

[...]