SQL Performance

If you have to access persisted data, of course, you do not have to necessarely use SQL. But in case you do, knowing something about SQL-performance helps. I just did…

Gesture

Lots of SF movies and futerist though that the future interface of the computer would be voice: talking to your computer like it was a human. Nothing less is true:…

Filesystem notifications in Java

Inspired by an OS that went in oblivion some years ago (BeOS) operating systems as Windows, Linux and MacOS all have ways to monitor directories for changes built into the…

Databases on SSD

SSD disk are becoming increasingly popular. As they read faster, you might consider running databases such as Oracle DBMS, MySQL or non-sql databases. However, interestingly, originally databases are optimized for…

OpenID from my website

A lot of websites now provide a way to authenticate yourself via OpenID. That way, you don’t have to remember a separate username and password to login to such a…

Wicket Exception when using wrong order in addComponent

Today I working on a application that uses the Wicket framework. I was plagued with the following Exception: WicketMessage: org.apache.wicket.WicketRuntimeException: component myForm:myTable:editor not found on page nl.gerbrand-ict.gui.HomePage[id = 4], listener…

Database upgrade during deployment

I want to create an installation package of a Java application. Part of the installation involves upgrading a SQL database (Oracle) – by running a few SQL scripts. Creating the…