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.
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.
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.
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.
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.
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.
In this post we will take a closer look at Spring Actuator and highlight some changes of it in Spring Boot 2.0. We will discuss some of the endpoints and will create a custom endpoint to our application. The sources can be found at GitHub.