By now, you are probably aware of that Google has brought Java to it’s App Engine platform. Yesterday, I downloaded the Google SDK for trying out how things are in Java App Engine. The Google Code site also present a link to download the Google Eclipse plug-in (in my previous post, I wrongly mentioned that the plug-in was under-development!). So, I installed both the SDK and the plug-in and started my Eclipse IDE.
What you get with the Google SDK:
Google SDK comes with the necessary API files that are needed to simulate the App Engine environment in your local machine. A library for the data maintenance (Data Nucleus), API to simulate the Google User authentication and a in-built web server (Jetty). So, with a single bundle of SDK, you get everything that you need to develop Java app for Google App Engine.
Apart from the JARs, the SDK bundle also includes several Java App Engine demo applications, including the examples for the User authentication, data access. And the demo folder includes a template folder structure which you could use for creating new projects.
The Google Eclipse Plug-in:
As you would have guessed, the Google Eclipse Plug-in adds Java App Engine development support to the Eclipse platform. After installing the plug-in and configuring the Google SDK with Eclipse, you can create a New Web Application Project, which is a Java project for Google App Engine. While you are creating your projects in this fasion, the plug-in itself configures the project structure for you.
And the plug-in also comes with an option to upload your projects to Google App Engine website, which will be handy feature.
As I’ve already told here, the Google Eclipse plug-in helps the developer a lot in his/her development. Another thing I liked in this plug-in is, whenever you create a new project, by default it creates the ‘Hello World’ servlet and puts the code in for you. So, yesterday when I just tried the App Engine SDK, I didn’t even write a single line of code to test the ‘Hello World’! 
Yet to explore more on this SDK. Currently I’m converting my notes tagging application to App Engine platform. I hope that this will give me more insight in Google SDK and Java App Engine support.
[Quick Tip] Change the App Engine Server’s port number:
By default, Google App Engine SDK’s web server (Jetty) runs on the port 8080. If you want to change this, go to the file $SDK_HOME\config\user\ant-macros.xml and change he port number in the property <attribute name=”port” value=”8080″ />.
{ 6 comments… read them below or add one }
This is going to be very interesting area this year for me.
Making java support will take this to next league.Gotta work on it.
@Thejesh
definitely it will!
@Hariharan,
Yes. and if PHP also supported, then GAE will be a great platform for the web developers.
Did you check the DB side? I am curious to know stuff about data persistence. Its OK to use JPA but still I am unable to figure it out that how my data will be stored. Is Google is providing some interface to fetch data and stuff like that….
Comments…???
not yet, Tahir. Have to check it out. Was bit busy with my office work, so didn’t get time to explore it further!
Making java support will take this to next league.Gotta work on it.