How to set or change the default Java (JDK) version on OS X?

Question

How can you change the default version of Java on a mac?

Answer 1

An easy way to include a separately installed JDK in the list given by /usr/libexec/java_home -V is to symlink the directory as follows:

sudo ln -s path/to/jdk /Library/Java/JavaVirtualMachines/jdk-[some-identifier].jdk

For example, to register the JDK included with Android Studio (1.8.0_152 at the time of writing), use:

sudo ln -s /Applications/Android\ Studio.app/Contents/jre/jdk /Library/Java/JavaVirtualMachines/jdk-android-studio.jdk

Now java_home will list the JDK under Matching Java Virtual Machines and you can select it as described above.