Category: kotlin

Posts in kotlin

Adding Context to Extension Functions

Extension functions are great! But if you define them all over the place, it can get confusing pretty quickly. So here’s a cool idiom to limit extension function usage to a specific context.

written August 21, 2021 in extension-functions, idioms, kotlin Read on →

Mockk All the Things

Over the last few years Mockk has been gaining ground as the go-to mocking library in KotlinWorld ™. Just recently, it was listed as “adopt” in the [ThoughtWorks technology Radar][1]. Want to know what all the fuss is about?

written May 9, 2019 in kotlin, mocking, mockk, spy, stub, test Read on →

Different Kinds of Channels in Kotlin

Overview of the different kinds of Kotlin channels and their behaviors.

written April 18, 2019 in channels, concurrency, coroutines, kotlin Read on →

SQS Consumer Using Kotlin Coroutines

Today we’ll see how to write a SQS consumer that processes messages in a parallel, non-blocking way, using Kotlin coroutines.

written February 23, 2019 in aws, consumer, coroutines, kotlin, producer, queue, sqs Read on →

Using UUID on Spring Data JPA Entities

In this article I’ll explore how to model a [JPA Entity][1] using an [UUID][2] as Primary Key working with [Spring Data JPA.][3]

written November 5, 2018 in data, hibernate, jpa, kotlin, spring, uuid Read on →

Reactive GraphQL Subscriptions From Kafka

In this post I’ll be exploring how to implement [GraphQL subscriptions][1] reactively on a Spring Boot application using [Kafka][2].

written October 23, 2018 in boot, graphql, kafka, kotlin, reactive, reactor, spring, subscriptions Read on →

Random Thoughts on Using Gradle With Kotlin DSL

Since Gradle 3.0 you can [write your build scripts using Kotlin instead of Groovy][1]. I was curious, so I decided to give it a try. Here are my thoughts on the process.

written August 28, 2018 in gradle, kotlin, kotlin-dsl, multi-module, spring Read on →

JaCoCo & Kotlin: Coverage on Generated Code

JaCoCo works flawlessly with Kotlin. Except when it reports lines not covered on generated code 😡. Fortunately there’s a fix already in place.

written August 12, 2018 in coverage, generated, jacoco, kotlin Read on →

Hierarchical Queries on RDBMS With JPA

Hello! In this post I’ll explore the different alternatives for querying hierarchical data stored on a RDBMS using [JPA][1].

written August 4, 2018 in graph, hierarchical, jpa, kotlin, query, rdbms, recursive, sql Read on →

Writing Githooks in Kotlin

You’re already using Kotlin on your codebase. Maybe, you’ve even migrated to the new [Kotlin DSL for Gradle][1]. Wouldn’t it be nice if you could use Kotlin for your [git hooks][2] too?

written July 3, 2018 in git, githook, gradle, kotlin, quality Read on →

Oracle, JPA and the Mystery of the String That Was Null

This is the story of how Oracle DB was messing up Kotlin’s type system, and what I did to fix it.

written June 23, 2018 in h2, jpa, kotlin, npe, nulls, oracle, oracle-db, spring, spring-data Read on →

Implementing takeWhileInclusive in Kotlin

Implementing takeWhileInclusive extension function in Kotlin.

written June 2, 2018 in collections, extensions, kotlin, takewhile Read on →

Spring Functional Routing

This post is about the clever tricks you can pull with Spring new functional routing and it’s Kotlin DSL.

written May 20, 2018 in dsl, functional, kotlin, router, routing, spring Read on →

Parallel Map in Java (From Kotlin)

Following up of my [previous post][1], I was curious how a parallel map operation would look like using Java’s [parallelStream][2]. Here’s what I find out.

written May 7, 2018 in collections, java, kotlin, parallel Read on →

Parallel Map in Kotlin

Ever wonder how to run [map][1] in parallel using coroutines? This is how you do it.

written May 4, 2018 in collections, coroutines, kotlin, parallel Read on →

Go Channels in Kotlin - an Example

This is the story of a real use case that was solved by using [Go style channels in Kotlin][1].

written April 23, 2018 in channels, coroutines, go, kotlin Read on →