Install Homebrew by running the following command in the terminal:

/bin/bash -c "$(curl -fsSL https://raw.githubusercontent.com/Homebrew/install/master/install.sh)"


Run the following commands in the terminal to install Java8:

brew update
brew cask install java

To install other versions of Java simply add the version number:

brew cask install java6
brew cask install java7

In order to easily switch between Java versions with a short command, the bash profile will have to be updated. If you have not previously created a bash profile do so by running the following command:

touch .bash_profile

Now run the next command to open the bash profile:

open -a TextEdit.app .bash_profile

Add the following lines to your bash profile and save it

alias j8="export JAVA_HOME=/usr/libexec/java_home -v 1.8; java -version"
alias j7="export JAVA_HOME=/usr/libexec/java_home -v 1.7; java -version"
alias j6=“export JAVA_HOME=/usr/libexec/java_home -v 1.6; java -version”

You can now switch between Java versions by typing j6, j7 or j8 in the terminal.