Lately I have been looking into and playing around with the Google App Engine. In this post I want to give a little introduction to the Google App Engine, why it can be interesting and how to work with it.
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Posts Tagged ‘Java’
Free Java hosting with the Google App Engine
February 4th, 2010 by Tom van Zummeren(http://blog.jteam.nl/2010/02/04/free-java-hosting-with-the-google-app-engine/)
Mahout – Taste :: Part 1 – Introduction
December 9th, 2009 by Frank Scholten(http://blog.jteam.nl/2009/12/09/mahout-taste-part-one-introduction/)
This post is the first in a series on Taste, a Java framework for providing personalized recommendations. Taste is part of the larger Mahout framework, which features various scalable machine-learning algorithms. In this post I introduce you to the concepts of personalized recommendations, also known as collaborative filtering. After this introduction, Taste’s architecture and extension points are explained. I finish this post by demonstrating and explaining the TanimotoCoefficientSimilarity, one of Taste’s implementations used for computing recommendations.
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A new and improved Spatial Solr
November 18th, 2009 by Preeti Gholap(http://blog.jteam.nl/2009/11/18/a-new-and-improved-spatial-solr/)
Introducing the Solr Spatial Plugin
What do a directory services company, a wholesaler of bathroom fittings, a social events guide, an oceanographic data centre and the pan-European library initiative have in common? They all need to offer their clients the ability to search and filter results within a flexible geographic area, defined by the user.
With a variety of businesses needing to customize search results to the preferences of a narrowly targeted audience, there’s an increasing demand for incorporating geographical location information into standard search functionality.
In response, JTeam has recently launched the Solr Spatial Plugin (SSP): a free, standalone, enterprise-ready plugin enabling location based search, built on top of the open source project Apache Solr.
Improved field collapse response
November 11th, 2009 by Martijn van Groningen(http://blog.jteam.nl/2009/11/11/improved-field-collapse-response/)
In the most recent contribution to field collapsing I have improved the response format. The old format was not properly structured, the naming of the elements not self explanatory and in some situations the response was even flawed. From my opinion a better response format was necessary in order to improve the stability of the patch and to make parsing the response easier.
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Securing connections with TLS
November 10th, 2009 by Erik van Oosten(http://blog.jteam.nl/2009/11/10/securing-connections-with-tls/)
In this article I’ll explore some ways to secure socket communication with TLS from a java application. To make it more concrete I’ll show you SubEtha SMTP (an excellent Java based bare bones SMTP server) and the recent TLS extensions I added to it.
What you’ll get from this article:
- How to mix secure with insecure communication
- How to start TLS, server side
- How to make the connection really safe
- How to add client authentication
- How to apply this with SubEtha SMTP
I’ll assume you know Java, understand the concept of a socket and the purpose of TLS/SSL.
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Exploring the world of Android :: Part 3
October 8th, 2009 by Tom van Zummeren(http://blog.jteam.nl/2009/10/08/exploring-the-world-of-android-part-3/)
In my travels through the world of Android I faced a lot of challenges. Brave as I am, *cough* I conquered each one of them. A few of the challenges include saving activity state, asynchronous tasks, pagination, error handling, context/option menu’s and even drawing custom application/tab icons in Photoshop! Some challenges I already shared with you guys, but there is one challenge in particular I would like to elaborate on this time.
The app I am currently building is getting larger every day, and so is the main Activity class! Because my main activity contains a TabHost with a bunch of tabs, it also contains references to all individual view components contained in those tabs. All kinds of listeners are registered on those components so the activity contains some inner and anonymous classes as well. So you could say that this activity now has way too much responsibility! What I was looking for, is a way to separate the main activity into multiple parts, each with its own clear responsibility.
As it turns out, you can create custom components for a single piece of functionality within an Activity. Exactly what I was looking for!
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Exploring the world of Android :: Part 2
September 17th, 2009 by Tom van Zummeren(http://blog.jteam.nl/2009/09/17/exploring-the-world-of-android-part-2/)
And I’m back! Reporting live on the glorious adventures in the exciting world of Android. This blog post is the second one in the Android series. This time with code samples! Yeah!
In my first blog post about Android I talked about setting up a project using Android. This time I want to discuss a more “advanced” topic: ListView performance. A ListView is a view component which allows you to display and scroll through a list of items. It can display simple text in each row, but is also able to display a more complicated structure. In the latter case you will need to make sure your ListView still performs well (read: renders fast and scrolls smoothly). I am going to provide solutions to a few different performance problems when using a ListView
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Wicket do’s and don’ts
September 16th, 2009 by Erik van Oosten(http://blog.jteam.nl/2009/09/16/wicket-dos-and-donts/)
In the past 2 years I worked in, and visited many development teams to help them implement divers Wicket applications. Some applications were mostly for visualizing stuff, some were full of forms, and some were full of Ajax tricks. This article contains some of the lessons I had to teach, or had to learn myself. I’ll present them as do’s and dont’s. They are:
- Do use models
- Don’t use an Ajax library without intimate knowledge of the library
- Do make sure you understand the repeaters for high performance sites
- Don’t overuse inheritance
- Do keep markup in sync with the component code
- Don’t try to do authorization from a servlet filter
- Do take your time to override key Wicket features
Feed Your Database
September 10th, 2009 by Aparna Chaudhary(http://blog.jteam.nl/2009/09/10/feed-your-database/)
The priority that performance testing gets among other development activities is always less; it is an “afterthought”, not a critical, ongoing part of the development process. Typically, it is done in higher environments like ST, QA. Some attention is given to performance in the prior SDLC cycles like design by making proper selection of frameworks. But during development its often limited to following the right coding standards. With this approach, the performance issues accumulate over time and then these bottlenecks become project killers.
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Exploring the world of Android :: Part 1
September 8th, 2009 by Tom van Zummeren(http://blog.jteam.nl/2009/09/08/exploring-the-world-of-android-part-1/)
For a short while now, I am developing for the Android platform, which is a mobile phone operating system developed by Google. The language to use is Java, so at least I didn’t have to learn an entirely different new language and I can use the tools I already know and love. I would like to tell you about my ‘adventures’ as I explore the world of Android 
When I first started studying the Dev Guide I soon discovered that the recommended IDE for developing Android applications is Eclipse. Which was a bit disappointing because I don’t like Eclipse that much. But fortunately the kind folks of Google left room for other IDE’s to develop with. They explain that when you use another IDE you will have to use all kind of command line tools instead, which they provide. Those command line tools allow you to compile your code for Android, run your application in a phone emulator, connect a debugger to your emulator, view application logs and stuff like that. But what they didn’t mention, is that if you use Intellij IDEA (which happens to be my favorite IDE) it also provides good support for Android! This makes the use of most provided command line tools superfluous.
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