控制台：
vim ~/.bash_profile
添加如下配置
export JAVA_13_HOME=/Library/Java/JavaVirtualMachines/jdk-13.0.2.jdk/Contents/Home
export JAVA_8_HOME=/Library/Java/JavaVirtualMachines/jdk1.8.0_211.jdk/Contents/Home
export JAVA_HOME=$JAVA_13_HOME
alias jdk8='export JAVA_HOME=$JAVA_8_HOME'
alias jdk13='export JAVA_HOME=$JAVA_13_HOME'
保存后：source ~/.bash_profile
来回切换
1、先输入jdk8或者jdk13
2、java -version
移除jdk
sudo rm -r -f /Library/Java/JavaVirtualMachines/jdk1.8.0_211.jdk