Install Open JDK in Mac

# Note
# On Mac OSX, Java should installed in this folder; it is Mac’s standard.
/Library/Java/JavaVirtualMachines/

# Update repo
brew update

# Add adoptopenjdk/openjdk
brew tap adoptopenjdk/openjdk

# Find all available JDK.
brew search jdk

# Install JDK
brew cask install adoptopenjdk8

# JDK will installed in
/usr/libexec/java_home -V

# Now Homebrew will install the JDK at folder /Library/Java/JavaVirtualMachines/
# If we install multiple version of jdk, by default, Mac takes the highest version.

# In .bash_profile, add following code
export JAVA_HOME_8=$(/usr/libexec/java_home -v1.8)

# Java 8
export JAVA_HOME=$JAVA_HOME_8