As expected, Google today announced that it has added Java support to its App Engine service. It was announced at a Google Campfire this evening as part of a major upgrade for the Google App Engine that includes the release of database importer tools, secure data connectors and other such features that are critical to web builders:
First, we’re giving developers an ‘early look’ at Java™ language support for App Engine. The team has taken a standards based approach, implementing standard Java APIs on top of App Engine where possible. So instead of using the underlying App Engine datastore API, developers can program against Java Data Objects or Java Persistence API.
Developers will also be able to easily build AJAX web applications end-to-end in Java through integration with a new version of Google Web Toolkit and a Google Plugin for Eclipse to support the development experience. (Google Code Blog)
If you are trying to figure out why Java support is important, take a few moments and read my analysis.