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Archive for the ‘Google App Engine’ Category

[GWT] Table with pagination and one sortable column

April 10th, 2011 No comments

I just added a very basic GWT project to my github account to display a table with pagination and one sortable column.
The code is mostly based on the official GWT tutorial :
http://code.google.com/intl/en/webtoolkit/doc/latest/DevGuideUiCellTable.html

I basically just added the SimplePage element to handle pagination :

SimplePager pager = new SimplePager();
pager.setDisplay(table);

Source :
https://github.com/longbeach/MyFirstCellTable
Demo :
http://tableaupagination.appspot.com/

Categories: Git, Google App Engine, GWT, SCM Tags:

How to rollback a transaction in GAE

April 10th, 2011 No comments

This has nothing to do with JPA.
I was trying to deploy a GWT webapp to GAE when I suddenly got an error.
As a remedy, i got the message :
"java.io.IOException: Error posting to URL: https://appengine.google.com/api/appversion/create?app_id=tableaupagination&version=2&
409 Conflict
Another transaction by user xxxxx is already in progress for this app and major version. That user can undo the transaction with appcfg.py's "rollback" command."

After digging into Google a bit, I found that the way to launch that rollback command under Windows is the following :
1) Figure out where the Google App Engine Java SDK directory is.
In my case, it’s under the Eclipse plugins directory :
D:\Dev\eclipse-jee-helios-SR1-win32\plugins\com.google.appengine.eclipse.sdkbundle.1.4.2_1.4.2.v201102111811

The bin folder contains the appcfg.cmd command.

2) Under a DOS command prompt, go to the workspace folder of your project and launch the following command :
"D:\Dev\eclipse-jee-helios-SR1-win32\plugins\com.google.appengine.eclipse.sdkbundle.1.4.2_1.4.2.v201102111811\appengine-java-sdk-1.4.2\bin\appcfg" rollback war

After that, you can try to deploy the app again and it should work.

Links :
http://code.google.com/intl/fr/appengine/docs/java/tools/uploadinganapp.html
http://code.google.com/intl/fr/appengine/docs/java/gettingstarted/uploading.html

Categories: Google App Engine, GWT Tags:

[Tutorial] Create your first GWT project and deploy it to GAE

April 9th, 2011 No comments

Here is a first quick and simple tutorial on how to develop and deploy your very first GWT web application to Google App Engine.

Requirements :
Eclipse
Google Web Toolkit plugin for Eclipse
A Google App Engine account + GMAIL account

So here are the steps :
Read more…

Categories: Google App Engine, GWT, Tutorials Tags:

I am not a GAE virgin anymore

January 30th, 2010 No comments

Well, I do not have much spare time to take a deep look at all the new technologies that come around but i always try to check at least the minimum.

Google App Engine offers a nice tutorial : http://code.google.com/appengine/docs/java/gettingstarted/

I did not run into any major problem.

The result is a very basic and classic guestbook application.

Building and uploading the web application from Eclipse to the App Engine is a piece of cake. You must first receive a code on your phone in order to create an application ID :

GAE_ID

You can see it here :  http://celfertest.appspot.com/

I am looking forward for more fun with GAE in the near future, when I have the time.

Categories: Google App Engine, iPhone Tags: