Yesterday, Google announced App Engline Java 7 runtime as one of its 'experimental' features that is on its way towards wider availability. Here's a slice of the announcement; you can find useful code examples by heading over to the original post.
The App Engine Java 7 runtime allows App Engine developers to keep pace with innovations in the Java language and runtime. It is important that you begin testing your applications with the new Java 7 runtime before the complete rollout in a few months.
Some of the language features you now have access to include . . .