Blog Archives

How to Clone & Reuse VirtualBox Disk-Images under Linux

When working with Oracle VirtualBox you might have come accross situations, where you wanted to copy the state of a given Disk-Image and build a new Virtual Machine upon that. We tell you, hot to do that. a) Preparations Before

Posted in Build Process, Infrastructure, Software Engineering, Uncategorized

How to change ssh port on CentOS 7

Recently one of our server has welcomed us with ugly messages like: Last failed login: Fri Aug 22 19:31:42 CEST 2014 from on ssh:notty There were 17307 failed login attempts since the last successful login. Last login: Wed Aug

Posted in Data Security

Confusing Comparable- & Comparator-Contract

Read here more about the Confusing Comparable- & Comparator-Contract in Java today. I recently came accross the following exception, thrown by the Java Runtime Environment: “Comparison method violates its general contract!” The Exception occurred in a Comparable-implementation looking similar as

Posted in Software, Software Architecture, Uncategorized

Backing-up your most valuable Data

In this previous post you found instructions, how to setup a USB-stick to contain an additional hidden encrypted partition to store valuable data on. Here you learn how to use your secured USB-stick and backing-up your most valuable data, based

Posted in Data Security, Knowledge

Cannot load JDBC driver class ‘net.sourceforge.jtds.jdbc.Driver’

This Blog shows you some possible causes when getting the Exception above using Eclipse with multiple installed Java Runtime Environments. For this tutorial we’ve been using ‘Spring Tool Suite Version: 3.1.0.RELEASE’, together with Apache Maven version 3.0.4 (r1232337; 2012-01-17 09:44:56+0100).

Posted in Eclipse, Software Engineering

Data Security without the Cloud

This post shows a simple solution to backup your most valuable documents on a USB-Stick in an hidden and encrypted form, such that the data is not easily recognizable and accessible for unauthorized users. Users connecting the Stick would just

Posted in Data Security

Cloud or no Cloud, that’s the question!

This post is about the question, wheter or not you should use cloud services in order to backup your data. Compared to traditional backup solutions using hard drives there are lots of advantages you win when going for a cloud

Posted in Data Security, Enterprises

Match multibyte Characters with Regex in JAVA

When working intensively with regular expressions in JAVA and other languages than english are involved, you are bound to meet unexpected behaviour, at least when trying to cope with it the first time. This post teaches you how to match

Posted in Regular Expressions, Software Engineering

Sort String Tokens alphabetically in JAVA

This is an example to show a simple way of sorting String Tokens alphabetically in JAVA. We’re using the StringUtils helper-class provided by the Spring-Framework to realize this exmaple. Add the following dependency within your pom.xml to have StringUtils available:

Posted in Software Engineering, Spring Framework

Query to select top-n Records from each Group (TSQL)

Often I come accross a task where I need to select the top-n records from each group from a given set of data, where each subgroup is defined by having a specific attribute in common. To demonstrate how this is

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Posted in Databases, TSQL (MSSQL)