Multiple Java Environmental Science

Because the project needs , need jdk11 To run a project , But other projects are jdk1.8 Of , It is inconvenient to replace directly jdk, So you need to configure multiple on one machine jdk

install jdk11

1. download jdk11
   File download address ：https://download.java.net/java/GA/jdk11/13/GPL/openjdk-11.0.1_osx-x64_bin.tar.gz

2. Unzip the installation package （ The default installation location in the system ：/Library/Java/JavaVirtualMachines/）

sudo tar -zxf openjdk-11.0.1_osx-x64_bin.tar.gz -C /Library/Java/JavaVirtualMachines/

3. verification
   

4. Configure environment variables

（1） ~/.bash_profile Modify environment variables

Replace according to the version installed by yourself

export JAVA_8_HOME=$(/usr/libexec/java_home -v1.8)
export JAVA_11_HOME=$(/usr/libexec/java_home -v11)
export JAVA_17_HOME=$(/usr/libexec/java_home -v17)
#alias Command dynamic switching JDK edition 
alias jdk8="export JAVA_HOME=$JAVA_8_HOME"
alias jdk11='export JAVA_HOME=$JAVA_11_HOME'
alias jdk17='export JAVA_HOME=$JAVA_17_HOME'

perform source ~/.bash_profile Make the above settings work

6. Multiple version switching tool JEnv
   install

brew install jenv

To configure JEnv environment variable

echo 'export PATH="$HOME/.jenv/bin:$PATH"' >> ~/.bash_profile \
&&echo 'eval "$(jenv init -)"' >> ~/.bash_profile \
&&source ~/.bash_profile

5. To configure jenv
   View all JDK The default installation location in the system

/usr/libexec/java_home -V

Add directory to jenv Ongoing management

jenv add /Library/Java/JavaVirtualMachines/jdk1.8.0_101.jdk/Contents/Home

View added versions

jenv versions

6. Manual switching

jenv global 11.0

Reference resources ：
https://www.cjavapy.com/article/91/
https://blog.csdn.net/aqzwss/article/details/54318921