How to Monitor a Spring Boot App

In this blog you will learn how to monitor a Spring Boot application. You will make use of Spring Actuator, Micrometer, Prometheus and Grafana. Seems a lot of work, but this is easier as you might think!

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How to Start Contributing to Open Source

Every now and then, the idea of contributing to Open Source Software crosses the mind of every developer. However, often, it just remains to think about it instead of actually doing something. In this blog, I want to tell the story of my first Pull Request.

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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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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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Devoxx Belgium 2019 Impressions

Devoxx Belgium 2019 took place in the first week of November. I attended the Conference days and with this post I want to share how I experienced the event and the different talks I attended. This is a strongly opinionated post and it represents my opinion only.

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How to Solve Your Java Performance Problems (Part 2)

In the first part of this post, we explained the Performance Diagnostic Methodology (PDM) and how to use it. But, the proof of the pudding is in the eating and therefore it is now time to apply the methodology. Of course, the best proof would be to apply the methodology to a real world performance issue, but instead of waiting for that, we will try to simulate some performance issues and verify whether the methodology can work.

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How to Solve Your Java Performance Problems (Part 1)

Last June I saw an interesting conference talk at J-Spring given by Martijn Verburg (from jClarity) about the Performance Diagnostic Methodology (PDM), a structured approach in order to find the root cause of Java performance problems. In this post I will try to highlight the key concepts but I do recommend watching a recording of the talk from Devoxx UK. In the next part of this post, we will try to apply the theory to some problem applications.

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J-Spring 2018 impressions

On Thursday the 31st of May I went to the J-Spring conference at Utrecht, the Netherlands. J-Spring is the largest one day Java conference in the Netherlands in the spring organised by the NLJUG (Dutch Java User Group). The title of the event might be a bit misleading as you may think that it is only about Pivotal’s Spring, but it is more than that. In this post I want to share my experiences that day.

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Project Lombok: Reduce boilerplate code

In this post we will take a look at Project Lombok and what it has to offer us. Project Lombok reduces boilerplate code by making use of annotations in your code. Main advantage is achieved with POJO’s (Plain Old Java Objects): you don’t have to code getters and setters anymore. Although your IDE provides the possibility to generate getters and setters, with Project Lombok you also don’t have to read them anymore. Source code used in this post can be found at GitHub.

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