Not so easy functional programming in JavaScript
Introduction
JavaScript allows for operating on arrays in a functional way, e.g. using filter or map functions. As an argument for these functions we can Read more
Loops performance in Groovy
IntroductionIn the 2018 Advent of Code challenged I solved all the puzzles in Groovy. It is pretty obvious, that choosing good data structure is the most important to obtain performant solution. However, the way we iterate over those structures is also... Read more
Testing Kotlin with Spock Part 3 – Interface default method
Kotlin allows you to put method implementation in an interface. The same mechanism can be found in Java interfaces as default methods (and also Groovy Read more
Testing Kotlin with Spock Part 2 – Enum with instance method
The enum class with instance method in Kotlin is quite similar to its Java version, but they are look a bit different in the bytecode. Let's see the difference by writing some tests using Spock.What do we want to test?Let's see the code that we want to... Read more
Testing Kotlin with Spock Part 1 – Object
The object keyword in Kotlin creates singleton in a very convenient way. It can be used for example as a state of an operation. Spock Read more
MapStruct mapper injection in OSGi Blueprint
What is MapStruct?According to MapStruct website:MapStruct is a code generator that greatly simplifies the implementation of mappings between Java bean types based on a convention over configuration approach. The generated mapping code uses plain metho... Read more
Karaf configuration as Groovy file
IntroductionBy deafault, Apache Karaf keeps configuration for bundles in the etc directory as flat properties files. We can override configuration for the storing mechanism by providing own implementation of the org.apache.felix.cm.PersistenceManager i... Read more
Easy fraud detection in Nigerian bank with TouK Nussknacker
Problem
We have a large mysql database with payment transactions from multiple banks, aggregated for Nigerian biggest operator. Each day the customers create about 300 Read more
Using Kotlin extensions in Groovy
Extensions in Kotlin and GroovyKotlin and Groovy have mechanisms for extending existing classes without using inheritance or decorators. In both languages, the mechanisms are called extension methods. Their source code looks different, but generated by... Read more
OSGi Blueprint visualization
What is blueprint?Blueprint is a dependency injection framework for OSGi bundles. It could be written by hand or generated using Blueprint Maven Plugin. Blueprint file is only an XML describing beans, services and references. Each OSGi bundle could hav... Read more