I'm working in Eclipse one night, (also using Android's DDMS from the commandline). The next morning, I open the lid... attempt to run Eclipse and get an error.

me$ sudo /Applications/eclipse/eclipse
JavaVM: requested Java version ((null)) not available. Using Java at "" instead.
JavaVM: Failed to load JVM: /bundle/Libraries/libserver.dylib

So I then attempt to find out where my JDKs are pointed:

me$ ls -la /System/Library/Frameworks/JavaVM.framework/Versions/
total 64
drwxr-xr-x  12 root  wheel  408 Nov 16 10:44 .
drwxr-xr-x  12 root  wheel  408 Sep  7 09:39 ..
lrwxr-xr-x   1 root  wheel    5 Sep  7 17:07 1.3 -> 1.3.1
drwxr-xr-x   3 root  wheel  102 Dec  2  2009 1.3.1
lrwxr-xr-x   1 root  wheel   10 Sep  7 17:07 1.4 -> CurrentJDK
lrwxr-xr-x   1 root  wheel   10 Sep  7 17:07 1.4.2 -> CurrentJDK
lrwxr-xr-x   1 root  wheel   10 Sep  7 17:07 1.5 -> CurrentJDK
lrwxr-xr-x   1 root  wheel   10 Sep  7 17:07 1.5.0 -> CurrentJDK
lrwxr-xr-x   1 root  wheel   10 Sep  7 17:07 1.6 -> CurrentJDK
drwxr-xr-x   9 root  wheel  306 Nov 16 10:44 A
lrwxr-xr-x   1 root  wheel    1 Sep  7 17:07 Current -> A
lrwxr-xr-x   1 root  wheel   59 Sep  7 17:07 CurrentJDK -> /System/Library/Java/JavaVirtualMachines/1.6.0.jdk/Contents

Everything looks normal so far...

me$ ls -la /System/Library/Java/JavaVirtualMachines/
total 0
drwxr-xr-x  2 root  wheel   68 Nov 16 10:44 .
drwxr-xr-x  5 root  wheel  170 Nov 16 10:44 ..

Apparently, my virtual machines have been deleted or moved?

I'll probably be able to just re-install Java, but does anyone have any insight into why this may have happened or how to prevent in the future?