已安装

• Homebrew 3.2.14
• jenv4.4
• java7

安装java8

下载安装包，需要oracle账号https://www.oracle.com/java/technologies/downloads/#java8-mac

安装后路径

jenv add /Library/Java/JavaVirtualMachines/jdk1.8.0_301.jdk/Contents/Home

#There is already a 1.8 JDK managed by jenv
#Do you want to override (type y to confirm)? y

jenv global 1.8
# 切换版本
jenv local 1.8
#查看版本
java -version

参考
Mac 下Java多版本管理工作：Jenv
mac使用brew安装Java8
mac笔记本安装JDK8