How to install Java 8 on osx macOS Mojave with Homebrew?

Assumption: Mac machine and you already have installed homebrew.

Install cask (with Homebrew 0.9.5 or higher, cask is included so skip this step):

$ brew tap caskroom/cask
$ brew tap caskroom/versions

To install latest java:

$ brew cask install java

To install java 8:

$ brew cask install adoptopenjdk/openjdk/adoptopenjdk8

If you want to install/manage multiple version then you can use 'jenv':

Install and configure jenv:

$ brew install jenv
$ echo 'export PATH="$HOME/.jenv/bin:$PATH"' >> ~/.bash_profile
$ echo 'eval "$(jenv init -)"' >> ~/.bash_profile
$ source ~/.bash_profile

Add the installed java to jenv:

$ jenv add /Library/Java/JavaVirtualMachines/jdk1.8.0_202.jdk/Contents/Home
$ jenv add /Library/Java/JavaVirtualMachines/jdk1.11.0_2.jdk/Contents/Home

To see all the installed java:

$ jenv versions

Above command will give the list of installed java:

* system (set by /Users/lyncean/.jenv/version)
1.8
1.8.0.202-ea
oracle64-1.8.0.202-ea

Configure the java version which you want to use:

$ jenv global oracle64-1.6.0.39

To set JAVA_HOME:

$ jenv enable-plugin export

The older Oracle JDKs are gone from Homebrew now. Use OpenJDK instead:

brew tap adoptopenjdk/openjdk
brew cask install adoptopenjdk8

OpenJDK is a drop-in replacement for the Oracle JDK in most places, so this should work fine for you with no code or build process changes.

This answer is outdated.

You can install Java 8 on macOS Mojave like this:

brew tap caskroom/versions
brew cask install java8

In case the latest java version was already installed, uninstall it with:

brew cask remove java

Updated commands that are working now:

brew tap homebrew/cask
brew tap homebrew/cask-versions
brew install --cask adoptopenjdk/openjdk/adoptopenjdk8