Oracle Sues Google Over Android

Oracle is apparently claiming Google owes them royalties for revenue generated by ads served in Android. The code that runs these ads was written in a version of java, as is much of the app dev in Android, therefore, so say Oracle, Google needs to cough up.

I'm having trouble with this. I admit I'm not familiar with the legal theories. But does this mean Oracle could sue anyone who develops something in Java and makes money off of it?