These days companies gather and manage vast amounts of user data. Loss of this data will expose companies to financial/legal liabilities or damages to their brand. This is because over the last years, governments have introduced new regulations like the General Data Protection Regulation (GDPR). Because of this, security is a major cross-cutting concern for application architecture. This two-part blog post explains how you can leverage Keycloak to secure your Spring microservices. The first blog will focus on how to install and configure Keycloak. The second blog will show how to use Keycloak to secure your Spring Boot microservices.

The Thoughtworks Technology Radar is well known for showing technology trends and choices. For my project I wanted to have the same thing, not use the hosted public version from Thoughtworks, but a selfhosted option. Therefore I choose to base it on the Zalando opensource tech radar, and create a way to use a CSV file as input so updating would be an easy thing to do. To accomplish that I took the following steps:

There are those moments you wish you could just start up a real database or system for your (integration) test. In many tests I’ve written I used H2 or HSQLDB to have a data storage for my tests. It starts up quickly and almost supports everything you need to do your repository test or any other test needing data storage. But when your project progresses you start using other ways to store your data other than standard SQL or you use dialect specifics to create your database. This is the moment you discover H2 or HSQLDB is not supporting your database vendor specific features and you can’t get your test running. For example the support for PostgreSQL in H2 or HSQLDB isn’t great, using TIMESTAMP in a SQL script already makes H2 or HSQLDB break. Yes, there are workarounds, but you rather not apply them to keep your code clean and simple. This is the moment you wish it is cheap to start up a real database instance you can test against, so you’re sure your code works in your production environment. You could install the database software locally, make some scripts to initialise the database and clean up afterwards. Or you can make scripts to do this in a Docker container. But what if there’s something which makes this even cheaper to setup?

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.

After the success of agile transformations that gave organisations the ability to respond to a change in the market more quickly and frequently, the last decade saw DevOps emerge as another magic wand. While valuable by itself, DevOps should actually be treated as one of many aspects of the Shift Left paradigm applied to the full software delivery life cycle. Patrick Debois, Andrew Shafer, John Allspaw and Paul Hammond coined the word DevOps around 2008. It comes down to the insight that combining the disciplines of development and IT operations by removing the thresholds between them allows for the elimination of waste and improvement of quality and speed of software delivery. The concept of Shift Left comes from the field of testing and boils down to the idea that the earlier in the software life cycle a fault is found, the cheaper it is to fix it. The accompanying model for this concept is that the process for delivering software goes from left to right as it goes from concept to cash.

When our Micronaut application starts we can listen for the ServiceStartedEvent event and write code that needs to run when the event is fired. We can write a bean that implements the ApplicationEventListener interface with the type ServiceStartedEvent. Or we can use the @EventListener annotation on our method with code we want to run on startup. If the execution of the code can take a while we can also add the @Async annotation to the method, so Micronaut can execute the code on a separate thread.

In our example application we have a reactive repository for a Mongo database and we want to save some data in the database when our Micronaut application starts. First we write a bean that implements the ApplicationEventListener:

As a software engineer you make architectural decisions all the time. Neal Ford calls these software engineers 'accidental architects'. I personally prefer the term implicit architects because I don’t think software engineers doing architecture is in any way an accident or even something you would not want. You’re the expert after all. Decision making is one thing though, how do you document these decisions?

Starting your next Javascript project can be frustrating or overwhelming when you have to set up your local development environment. The most of the new Javascript techniques and frameworks are dependent on node and NPM. Especially when you want to create a tutorial, blog post or prepare a workshop. The setup for each type of operating system can take to much time and your audience can lose the focus on the message you are trying to send. For this problem, CodeSandbox can help you out! On codesandbox.io you can start your next project with just one click and demonstrate, experiment or build cool stuff.

Although Java has always been awesome, Java 8 has brought the language several features the language was in dire need of. Apart from the long-awaited improved DateTime-API and the introduction of Optionals, Java 8 finally gave behaviour the attention it deserves by incorporating (a form of) functional programming into the language using lambdas.

The opportunities that Java 8 brought the language and the platform have long since been taken and functional styles of programming are part of our day-to-day routines as Java Developers. For-loops are a thing of the past for most of us, and although it had quite the learning curve, passing streams around and chaining operations on them to create some very readable code is common sense for us now.

Great projects keep moving forward. JUnit5 is available since September 2017 and Spock 1.2 is already complete. Since Spock is based on JUnit4, I wondered what it would take to use Spock 1.2 together with JUnit5.

As it turns out, it’s quite easy to make that happen. JUnit5 comes with the vintage engine to run JUnit4 based tests. If that is available on the test classpath, your Spock tests run like on JUnit4.

Making IntelliJ understand your QueryDSL generated classes needs some work. QueryDSL has an annotation processor to generate Q-classes from your entities. Just running the annotation processor doesn’t mean your IDE will understand where to find the generated classes. I was struggling to get IntelliJ IDEA picking up the generated classes. Probably there are more ways to get this done in Gradle, but I found out one that’s pretty easy to configure, without any adjustments to you IntelliJ settings. Because you could configure the annotation processor via the IntelliJ settings in the Annotation Processor screen (Build, Execution, Deployment → Compiler → Annotation Processors). It would be easier if you can achieve the same just using Gradle. With the following in your Gradle build file, it generates the classes and instructs IntelliJ where to find the classes:

If you’re using Lombok in your entities, generating the QueryDSL classes will fail, as it won’t understand the Lombok annotations. To solve this you have to add the Lombok dependency to the annotationProcessor block.

Back in '98 when I started with my CS education Java was the first programming language we were taught. Before I had experimented with QBasic, C and assembly but that was the moment where I started to really grow into being a software engineer. While I made something excursions to other languages; PHP, C#, JavaScript and even ColdFusion, Java always was my 'base' where I returned to. My great love as it were. But now she’s fallen out of fashion and I’m moving on to greener pastures: Kotlin.