Dakkar Dakkar - 4 months ago 63
Java Question

Mac OS X and multiple Java versions

How can I install an additional java on MacOS? I installed jdk8 and that works fine. but now I need a jdk7 installation for development purposes. When trying to install the old version via DMG file, i get a warning, that there is already a newer version of java installed and the installer quits.

/usr/libexec/java_home -verbose
Matching Java Virtual Machines (1):
1.8.0_20, x86_64: "Java SE 8" /Library/Java/JavaVirtualMachines/jdk1.8.0_20.jdk/Contents/Home

/Library/Java/JavaVirtualMachines/jdk1.8.0_20.jdk/Contents/Home


How to install jdk7 in addition to this one?

Thanks

Dakky

Answer

The cleanest way to manage multiple java versions on Mac is to use Homebrew.

And within Homebrew, use:

  • homebrew-cask to install the versions of java
  • jenv to manage the installed versions of java

As seen on http://hanxue-it.blogspot.ch/2014/05/installing-java-8-managing-multiple.html , these are the steps to follow.

  1. install homebrew
  2. install homebrew jenv
  3. install homebrew-cask
  4. install a specific java version using cask (see "homebrew-cask versions" paragraph below)
  5. add this version for jenv to manage it
  6. check the version is correctly managed by jenv
  7. repeat steps 4 to 6 for each version of java you need

homebrew-cask versions

Add the "caskroom/versions" tap to homebrew using:

brew tap caskroom/versions

Then you can look at all the versions available:

brew cask search java

Then you can install the version(s) you like:

brew cask install java7
brew cask install java6

And add them to be managed by jenv as usual.

jenv add <javaVersionPathHere>

I think this is the cleanest & simplest way to go about it.


Another important thing to note, as mentioned in Mac OS X 10.6.7 Java Path Current JDK confusing :

For different types of JDKs or installations, you will have different paths

On Mac OS X Mavericks, I found as following:

1) Built-in JRE default: /Library/Internet\ Plug-Ins/JavaAppletPlugin.plugin/Contents/Home

2) JDKs downloaded from Apple: /System/Library/Java/JavaVirtualMachines/1.6.0.jdk/Contents/Home/

3) JDKs downloaded from Oracle: /Library/Java/JavaVirtualMachines/jdk1.8.0_11.jdk/Contents/Home


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