mac上安装和卸载java的jdk

brew cask install java8   # 安装java8

/usr/libexec/java_home

vim ~/.bash_profile

JAVA_HOME=/Library/Java/JavaVirtualMachines/jdk1.8.0_152.jdk/Contents/Home
PATH=$JAVA_HOME/bin:$PATH
CLASSPATH=.:$JAVA_HOME/lib/dt.jar:$JAVA_HOME/lib/tools.jar

source ~/.bash_profile

echo $JAVA_HOME

sudo rm -fr /Library/Internet\ Plug-Ins/JavaAppletPlugin.plugin
sudo rm -fr /Library/PreferencesPanes/JavaControlPanel.prefPane
sudo rm -fr ~/Library/Application\ Support/Java

ls /Library/Java/JavaVirtualMachines/   # 查看jdk版本
sudo rm -rf /Library/Java/JavaVirtualMachines/jdk1.8.0_40.jdk  # 删除对应版本