Google App Engine Supports Java

Yesterday at Campfire '09 Google announced App Engine for Java "Early Look".

While it's still to be understood what quality level "early look" thing stands for, the fact is the solution is out and beats my expectations to the punch. Wow.

I call it a "solution" as there are many pieces to the puzzle and a lot of them received a good thought.

First of all, Google plugin for Eclipse provides an integrated development environment. Yes, IDE stands for that but I'd like to emphasize the "integrated" piece as the plugin allows you to deploy the code directly to App Engine.

Here's a video that demonstrates how to build and deploy an application on Google App Engine with Google plugin for Eclipse:



Third-party frameworks and libraries such as Spring are good to go for the most part.

Data access is abstracted via JDO and JPA.

Overall direction of following Java standards is very welcome and somewhat unexpected.

Batch jobs are supported - a must for any serious undertaking.

The flip side?

A number of popular frameworks such as Grails do not currently run "as is" on the engine.

From reading the datastore documentation I got a sneaky suspicion that JPA support is mostly on paper at this stage. It would be great to have it debugged and documented in a future release.

The concept of datastore based on Big Table will call for application architectures radically different from traditional database-backed systems. Data normalization and joins are important in RDBMS world - App Engine architects will have to say "bye-bye" to them.

It's unknown how restrictive the Java restrictions really are for practical purposes.

The coming weekend should provide some insight on where the solution sits on the quality meter.