


Managing Multiple Java Versions on Mac OS X
Context:
You have successfully installed JDK 8 on your Mac OS X system. However, you now require a JDK 7 installation for development purposes. Attempting to install the older version via a DMG file generates a warning about a newer Java version being already installed, resulting in the installer's termination.
Solution:
The optimal approach to managing multiple Java versions on Mac OS X is through Homebrew, a package management system. Homebrew employs two utilities for this task:
- homebrew-cask: Installs various Java versions.
- jenv: Manages the installed Java versions.
Steps:
- Install Homebrew.
- Install Homebrew jenv.
- Install Homebrew-cask.
- Install a specific Java version using cask. (Refer to the "homebrew-cask versions" section below for details.)
- Add the installed version to jenv for management.
- Verify that jenv manages the version correctly.
- Repeat steps 4-6 for each Java version required.
homebrew-cask versions:
Add the homebrew/cask-versions tap to Homebrew:
brew tap homebrew/cask-versions
Search for available versions:
brew search temurin
Install desired versions:
brew install --cask temurin8 brew install --cask temurin9
Add the installed versions to jenv:
jenv add <javaversionpathhere></javaversionpathhere>
Additional Considerations:
- Verify Java version paths using /usr/libexec/java_home -V.
-
macOS differentiates Java installations based on their source:
- Built-in JRE: /Library/Internet Plug-Ins/JavaAppletPlugin.plugin/Contents/Home
- Apple-downloaded JDKs: /System/Library/Java/JavaVirtualMachines/1.6.0.jdk/Contents/Home/
- Oracle-downloaded JDKs: /Library/Java/JavaVirtualMachines/jdk1.8.0_11.jdk/Contents/Home
Resources:
- [Removing Java 8 JDK from Mac](https://stackoverflow.com/questions/15196242/removing-java-8-jdk-from-mac)
- [Managing Multiple Java Installations with Homebrew](http://hanxue-it.blogspot.ch/2014/05/installing-java-8-managing-multiple.html)
- [Mac Setup](http://sourabhbajaj.com/mac-setup/index.html)
- [Homebrew](http://brew.sh)
- [Homebrew Documentation](https://github.com/Homebrew/homebrew/tree/master/share/doc/homebrew#readme)
- [Homebrew Cask](https://github.com/caskroom/homebrew-cask)
- [Jenv](http://www.jenv.be)
The above is the detailed content of How can I manage multiple Java versions on Mac OS X, especially when I have a newer version installed and want to install an older version?. For more information, please follow other related articles on the PHP Chinese website!

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