Posts by Ties van de Ven

Java streams vs for loop

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Ties van de Ven

I had quite a bit of trouble finding a good article about java streams vs for loops under this name so I guess I’ll have to write it myself. In this article I would like to talk about the difference of using the Streaming API and for loops from the standpoint of long term maintainability of the code.

tl;dr: To reduce maintenance costs of your projects, please do consider using the Stream API instead of for loops. It might take some investment in learning to do so, but this investment will pay off in the long run, both for the project and for the engineers.

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Java's difficulties with Functional Programming

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Ties van de Ven

In my early days I spent most of my time fixing bugs on a huge enterprise application, so by now I learned from experience that a lot of bugs could have been easily prevented. This is why I prefer a Functional Programming style, I love how FP handles state. As a software consultant I get to switch companies and teams quite regularly and most projects I have been working on use java 7 or 8. This almost always leads to a few dicussions regarding programming style. So today I would like to talk about good FP principles, and how Java makes them hard (and why languages like Kotlin are awesome).

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Get your application version with Spring Boot

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Ties van de Ven

There are a few ways to get your application version with Spring Boot. One approach is using Maven resource filtering to add the version number as an enviroment variable in the application.yml during the build. Another approach is to use the Implementation-Version stored in the manifest file.

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6 Steps to help you debug your application

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Ties van de Ven

As a developer sooner or later you will encounter bugs, be it small ones or production breaking bugs. Now it is your task to find and fix the bug as soon as possible. In this article I will list the techniques I learned over the course of many years debugging web applications in the hope that it will help you be better and more efficient in bug hunting.

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How to write bug free code - State

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Ties van de Ven

A lot of bugs are in some way related to state. So that is what we will be talking about today. We will start off with a quote from Einstein: “Insanity: doing the same thing over and over again and expecting different results. ” Code should be consistent, calling the same function with the same input should return the same result during the whole life cycle of the object. Insanity and bugs will follow if this rule is violated. This sounds logical, but in practise it is quite easy to violate this principle. The main cause of this, is object state. This state is used in a lot of functions, and can thus affect the behaviour of our program at runtime. This principle can be even be seen in the most basic of examples (imagine the impact on a more complicated class...). Given the following class:

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Integration testing on REST urls with Spring Boot

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Ties van de Ven

We are building a Spring Boot application with a REST interface and at some point we wanted to test our REST interface, and if possible, integrate this testing with our regular unit tests. One way of doing this, would be to @Autowire our REST controllers and call our endpoints using that. However, this won't give full converage, since it will skip things like JSON deserialisation and global exception handling. So the ideal situation for us would be to start our application when the unit test start, and close it again, after the last unit test. It just so happens that Spring Boot does this all for us with one annotation: @IntegrationTest. Here is an example implementation of an abstract class you can use for your unit-tests which will automatically start the application prior to starting your unit tests, caching it, and close it again at the end.

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