Somewhere between Java 6 and 7 it seems I lost track of where your JDK gets installed on Mac OS X. Prior to Java 7, it seems it was installed to:
/System/Library/Frameworks/JavaVM.framework/Versions
with symlinks pointing to the exact locations.
I was just setting up a new Eclipse install and was looking for where my 8 was installed – it was clearly installed as ‘java -version’ was telling me I was running 8, but it was no longer in the above location.
/usr/libexec/java_home (which I’ve mentioned before here) was telling me the following:
/Library/Java/JavaVirtualMachines/jdk1.8.0_20.jdk/Contents/Home
Hmm, so there you go. Looking in /Library/Java/JavaVirtualMachines/ I had multiple versions of 7 and 8. If you need to point Eclipse to a JRE location for your installed JREs, then from 7 onwards I think this is what you need.