After hearing from Google, I gave a try to Java support for Google App Engine. There are tutorials available at the official Google App Engine website. I decided to write my own tutorial for you guys to create a simple “Hello World “ web application on java and run it on Google App Engine. So here it is:
You need to install Eclipse for this tutorial
Finally the rumors have been confirmed and silenced, once and for all. 
Google https://www.programmerfish.com/category/app-engine-google/' target='_blank'>https://www.programmerfish.com/category/app-engine-google/' target='_blank'>App Engine team announced on their blog:
Today, we're very excited to announce the availability of a new programming language for Google https://www.programmerfish.com/category/app-engine-google/' target='_blank'>App Engine. Please welcome the Java runtime!
An application does not always use dynamic code to handle requests and there are plenty of
static content to be served as-it-is. For example, flash animations, images and stylesheets etcetera are all served directly without any processing required.
Google https://www.programmerfish.com/category/app-engine-google/' target='_blank'>App Engine does not provide any automatic way manage directory structure and it has to be specified in your app.yaml file. This is how it’s done:
Suppose your main app directory is helloworld and you have a stylesheet named style.css in helloworld/styles. This is how you edit your app.yaml file to map all requests to /styles to helloworld/styles directory. This is actually archived by URL re-writing.
Who says https://www.programmerfish.com/category/app-engine-google/' target='_blank'>App Engine aint attracting explosive developers to come develop and host their app on its cloud? Here is a collection of my picks of apps hosted on Google https://www.programmerfish.com/category/app-engine-google/' target='_blank'>App Engine:
Overgrowth is a 3d action-adventure game for Mac, Windows, and Linux, coming soon from the independent game studio, Wolfire Games.
https://www.wolfire.com/overgrowth
Who says scaling is free? It does come at a cost but not what you have to pay if you were managing your own mammoth server halls. Google today announced its pricing structure for https://www.programmerfish.com/category/app-engine-google/' target='_blank'>App Engine so incase your app is growing beyond your free assigned quota, you might consider taking some pennies out (yes, literally pennies!) and buy some more resources.
According to Google:
You can now set a daily budget for your app that represents the maximum amount you're willing to pay for computing resources each day. You allocate this budget across CPU, bandwidth, storage, and email, and you pay for only what your app consumes beyond the free thresholds -- prorated up to the nearest penny.
This screencast explains the process:
Yesterday we learned how to create a simple Hello World app on https://www.programmerfish.com/category/app-engine-google/' target='_blank'>App Engine and deploy it 
on the local web server that comes with https://www.programmerfish.com/category/app-engine-google/' target='_blank'>App Engine SDK. Read that tutorial here.
Now, once your app is complete, how to deploy it in the Cloud so that you can show it to the world!
First Step:
1) Create a Google account
2) Goto https://appengine.google.com and login
3) Click Create Application.
4) Select your country and enter your mobile number.
Cloud Computing is a buzz word now and every developer MUST know how to program and deploy on the Cloud be it Google’s https://www.programmerfish.com/category/app-engine-google/' target='_blank'>App Engine or Microsoft’s https://www.programmerfish.com/category/windows-azure-microsoft/' target='_blank'>Azure or Amazon’s EC2. Here is a very simple tutorial on how to create Hello World (traditionally the very first app we write on anything new we learn) on https://www.programmerfish.com/category/app-engine-google/' target='_blank'>App Engine.
Since it took me some time figuring out a some details which were very vaguely defined on the official text-tutorial on Google Code, so I thought of explaining it to the very minute detail for all the starters out there.
Step One (Get the Essentials):
Download Python Release 2.5.4
Download Google https://www.programmerfish.com/category/app-engine-google/' target='_blank'>App Engine SDK