Recently Google has included Java in its App Engine. Currently this release is an early look. Google is giving access to first 10,000 developers to deploy and test their Java applications and give their feedback.
What is Google App Engine?
Google is providing its scalable and managed deployment environment for developers. In Java environment JVM6, Servlet API, JDO, JPA, JavaMail and JCache libraries are available. They also have given an Eclipse plugin for it. Its Google managed deployment environment. Because it took a lot of time to deploy Java web applications. And a precious time wasted on just configuring web servers and DB server interfacing, rather this time used to develop the next application.
I found it interesting that this App Engine environment based on cloud computing. Where multiple servers run applications and dynamically handle resources based on requests to them.
Is it like application hosting?
I can say YES, but it is not like traditional hosting. Where you get UNIX based servers start connecting them through putty clients. And here comes where you need to manage every thing. App Engine stores data in BigTable a non-relational database developed on GFS (Google File System). It also a schedule mechanism known as Cron jobs which you can use to invoke HTTP request to a certain URL on specified time. If you want to run existing application, you have to do modifications in it about database access. Availability of Java based technologies which we traditionally used is also limited in App Engine. You can only develop in those technologies which are supported by it. App Engine has also replaced SQL with GQL.
So being Google on deployment side, its a great valuable thing that developers should start thinking to add features in their web applications rather thinking about running and configuring it.
What you need to get started?
If it interests you then for more understanding watch these videos by App Engine team at Google.