javaVersions is a oh-my-zsh plugin that adds aliases to your zsh.

You can change between different java versions with a single command.

1. Create a new directory in your oh-my-zsh/custom/plugin directory

mkdir ~/.oh-my-zsh/custom/plugins/javaVersions

2. Copy javaVersions.plugin.zsh file

cp ./javaVersions.plugin.zsh ~/.oh-my-zsh/custom/plugins/javaVersions

3. Enable the plugin by adding it to your plugins definition in ~/.zshrc.

plugins=(... javaVersions)

4. Reset your terminal

By default java8 is active. If you want to change the java version execute the command java{versionNumber}

https://github.com/robbyrussell/oh-my-zsh

https://github.com/robbyrussell/oh-my-zsh/wiki/Customization#overriding-and-adding-plugins

You can run the same aliases without oz-my-zsh. You've to add the aliases to your shell configuration file (.bashrc, .zshrc, etc)