Top 21 Techblog

facebook like button hack

I was wondering how they do it. You come to a website like www.web-burner.de/junge, you think its a simple video player and click the play button. Suddenly you have clicked an invisible facebook like button! How can this happen? The facebook Like-Button is an iFrame. It is pretty difficult these days to hack an iFrame and change its content to look like an video player.

After I had a look in the source code of the side, I recognized its acctually a pretty simple and effective hack. Nice idea, even if its not really "likable"!

Boosting the performance of jQuery 1.3.2 with the Sizzle selector engine 1.0 of jQuery 1.4.2

When using frameworks or plugins that are dependant on jQuery 1.3.2 you might not be able to upgrade to jQuery 1.4.x and therefore cannot enjoy the latest fixes and performance optimizations in your project. Not being able to use the latest version isn´t much of a problem considerung jQuery plugins - most of them are still compatible to jQuery 1.3.2 (right now). But it might get you into trouble if you´re faced with bugs in relation to the Sizzle selector engine that is included in jQuery. To solve these problems this article shows how to upgrade the selector engine of jQuery 1.3.2 to the faster and more stable version that is included in jQuery 1.4.2.

24hoster.com launches own URL-shortener

24hoster.com, the hosting division of Top 21 GmbH, launches it's own URL-shortener. At  24h.to we now provide URL-shortening for our customers but also for public use.

Generating QR Codes in Java with ZXing

QR Codes are used more and more including both commercial tracking applications and convenience-oriented applications aimed at mobile phone users (known as mobile tagging). QR Codes storing addresses and URLs may appear in magazines, on signs, buses, business cards, or just about any object that users might need information about. There´re is not a big choice on libraries for generating QR Codes in Java right now. One possibility is the open-source library ZXing. This article will give an example for using this library.

Why Java´s random number generation might block my application under Linux

In Java you can use Math.random() or SecureRandom to generate random numbers. The source for random numbers can be configured and depend on the operation system. This article describes the problem when generating random numbers on Linux might block the application server under several circumstances.