J-Spring Digital 2020 Impressions

This year’s edition of J-Spring, organized by the NLJUG, went digital due to the COVID-19 pandemic. From the 23rd up to and including the 26th of June, every day two technical talks have been held. We attended this digital version of J-Spring and want to share some of our impressions. Enjoy!

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Easy Integration Testing With Testcontainers

In this post, we will take a look at how we can use Testcontainers for our integration tests. Testcontainers will allow us to write integration tests making use of containerized databases, message queues, web browsers, etc. without a dependency on a local installation.

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Easy Database Migration With Liquibase

In this post, we take a look at how we can easily manage our database migration scripts by means of Liquibase. Liquibase will automatically execute necessary database migration scripts during application startup. We will explore some of the features of Liquibase by means of a simple Spring Boot application in combination with a PostgreSQL database.

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What Is Your Test Quality?

You have consistently written unit tests and you have a line coverage of, let us say, 80% and all of your tests pass. Pretty good, isn’t it? But then you change your code and still all of your tests pass although you have changed code which is covered by your unit tests. In this post, we will take a look at mutation testing which will test the quality of your unit tests.

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Skaffold: k8s Development Made Easy

Skaffold is a command line tool developed by Google which aims to facilitate continuous development for Kubernetes applications. It will automate the task of building and deploying to a Kubernetes cluster whereas you, as a developer, can stay focused on writing code. Seems interesting enough to take a closer look at it!

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Create Fast and Easy Docker Images With Jib

In this post we are going to take a look at Jib, a tool from Google in order to create Docker images in an easy and fast way. No need to create a Docker file, no need to install a Docker daemon, Jib just runs out-of-the-box.

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Introduction to Spring Kafka

Some blog posts ago, we experimented with Kafka Messaging and Kafka Streams. Although we used Spring Boot applications in order to demonstrate some examples, we deliberately did not make use of Spring Kafka. Reason for doing so, was to get acquainted with Apache Kafka first without any abstraction layers in between. Now that we have done so, it is of course time to take a look at Spring Kafka!

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Hack the OWASP Goat!

We will take a look at how we can get more acquainted with the OWASP top 10 vulnerabilities. After a short introduction about OWASP, we will show you how you can make use of WebGoat and WebWolf to get a better understanding of the OWASP top 10 vulnerabilities.

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Kafka Streams: Joins Explored

In this post, we will take a look at joins in Kafka Streams. Main goal is to get a better understanding of joins by means of some examples. The examples are taken from the Kafka Streams documentation but we will write some Java Spring Boot applications in order to verify practically what is written in the documentation.

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