Write once, test everywhere; or, Java reality != Java whalesong
Showing my age, I remember a leaked Sun internal memo from 2003, entitled "The Java Problem":
"It is impractical for a project based on Java to correct bugs in the Java implementation. Java Software corrects bugs only by releasing an entire new version. For that reason, projects seek to deliver their own copy of Java so they can maintain it without fear of a future upgrade. Outside vendors, such as TogetherJ, specify a particular release of Java for their product. The customer must locate that release and install it. If a future product seeks to use a different version, that version has to be installed side-by-side with the prior version or TogetherJ may no longer function.
The ARCs commonly see project submittals requesting permission to ship their own version of Java. The ARCs have been routinely forbidding projects to do this even though they are aware of specific cases wherein interfaces or their underlying behaviors have changed incompatibly across minor releases."
So in 2003, even engineers inside Sun wanted to bundle a separate JVM with each app to reduce the chances of JVM problems causing support issues. My question to current developers of mobile apps would be, do you still see enough variation between JREs on mobile devices that you end up having to test your apps on lots of different devices?
If mobile app developers do still need to test across a wide range of devices to have confidence that their apps will work, then any professed concern from Oracle about Google splintering the mobile Java app market is either defending an ideal which doesn't work, or simply an excuse for reasserting tight control over who gets to do what with Java, and how much they should pay for that privilege.