groovy – Team Blog

Loops performance in Groovy

byDominik Przybysz
January 3, 2019

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

DDevelopment & Design

Testing Kotlin with Spock Part 3 – Interface default method

byDominik Przybysz
September 27, 2018

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

DDevelopment & Design

Testing Kotlin with Spock Part 2 – Enum with instance method

byDominik Przybysz
May 28, 2018

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

DDevelopment & Design

Testing Kotlin with Spock Part 1 – Object

byDominik Przybysz
March 13, 2018

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

DDevelopment & Design

Karaf configuration as Groovy file

byDominik Przybysz
November 14, 2017

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

DDevelopment & Design

Tired of exporting your OSGI metatype to client manually?

byPiotr Fus
August 25, 2017

Feel my pain We use OSGi, but we don’t deploy our bundles further than testing environment. It is our client who deploys it to production. Read more

DDevelopment & Design

Using Kotlin extensions in Groovy

byDominik Przybysz
August 24, 2017

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

DDevelopment & Design

OSGi Blueprint visualization

byDominik Przybysz
February 18, 2017

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

DDevelopment & Design

Do not use AllArgsConstructor in your public API

byDominik Przybysz
January 17, 2016

Introduction Do you think about compatibility of your public API when you modify classes from it? It is especially easy to miss out that something Read more

DDevelopment & Design

Primitives and its wrapped types compatibility

byDominik Przybysz
December 13, 2015

IntroductionHow often do you think about possible changes in your API? Do you consider that something required could become optional in future? How about compatibility of such change? One of this changes is going from primitive (e. g. int) to its wrapp... Read more