Category Archives: Web

Google App Engine and sending Emails

Posted on February 3, 2011 by Lars Vogel

One of the nice things in the Google App Engine is that is it very easy to work with emails. You can send out and receive emails in your servlets. Lets demonstrate this by defining an application which allows the … Continue reading →

Posted in Web | Tagged , | 3 Comments

Google App Engine and JPA

Posted on January 10, 2011 by Lars Vogel

Using JPA on the Google AppEngine is straight forward. For some reason the documentation on the official Google App Engine side is not very easy to read therefore a little example here. Create a new web project “de.vogella.gae.persistence.jpa”. Change the … Continue reading →

Posted in Web | Tagged , , | 2 Comments

Build a “Management” Chat Bot in 5 steps with Google AppEngine

Posted on December 16, 2010 by Lars Vogel

Google AppEngine provides very cool features. One of these features is the XMPP API, that allows you to write apps that can interact with users through XMPP clients, e.g. Jabber or GTalk. Here’s a quick description how to create a … Continue reading →

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Integration of SAP with the Google App Engine

Posted on November 22, 2010 by Lars Vogel

Recently I though how I could integrate an SAP System which tends to be in a closed firewall where no access it granded from the outsite. The solution is actually quite easy. You can easily send our HTTP requests from … Continue reading →

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Making faces – How to display an image for all your blog comments

Posted on April 21, 2010 by Lars Vogel

Have you ever wondered why some people have a friendly face when posting a blog comment while others seems to look quite anonymous? Here is one possible solution: Gravatar provides a service which allows you to use a single avatar … Continue reading →

Posted in Eclipse, Softskill Topics, Web | 4 Comments

Integrating Twitter via Java

Posted on February 11, 2010 by Lars Vogel

This you want to integrate to Twitter from Java you can use the following library JTwitter. Try out the twitter integration with the following coding: Another Java Twitter Library is Twitter4J.

Posted in Java, Web | Tagged | 5 Comments

How can I use a Java jar file in a Grails application?

Posted on February 10, 2010 by Lars Vogel

After banging my head against the wall in trying to find out how I can use Java class in a Grails application I found out that the solution is embarrassing simple. Just create a jar file from your Java classes … Continue reading →

Posted in Java, Web | Tagged , | 1 Comment

How to create a transparent background for an image with Gimp

Posted on February 10, 2010 by Lars Vogel

The following will explain how to create an image with a transparent background with the freely available tool Gimp. GIF and PNG images can have transparent backgrounds. JPEG can not have a transparent background. Lets take the following example picture. … Continue reading →

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Google App Engine – Low level API for storing objects

Posted on January 18, 2010 by Lars Vogel

Google App Engine for Java permits three ways of storing your data: JDO, JPA and the low-level API. All data is ultimately stored in Bigtable. This blog post will give a little example how you can store data via the … Continue reading →

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