If you have multiple versions installed on your machine, add the following in bash profile:
export JAVA_HOME_7=$(/usr/libexec/java_home -v1.7)
export JAVA_HOME_8=$(/usr/libexec/java_home -v1.8)
export JAVA_HOME_9=$(/usr/libexec/java_home -v9)
And add the following aliases:
alias java7='export JAVA_HOME=$JAVA_HOME_7'
alias java8='export JAVA_HOME=$JAVA_HOME_8'
alias java9='export JAVA_HOME=$JAVA_HOME_9'
And can switch to required version by using the alias:
In terminal:
~ >> java7
export JAVA_HOME=$JAVA_7_HOME