Hello! In this post I will show you several ways how you can add module specific properties files in a Spring Boot project. It will cover a manual approach for making the property files profile aware and a semi automatic way that is profile aware. An example project is published on my Github account (https://github.com/coders-kitchen/spring-boot-multi-module-property-files). […]
JUnit rules – executing additional verification when exceptions are thrown
In this post I will show you quickly how handy JUnit rules are if you need to solve the following challenge A method catches an exception and has to perform some extra tasks before rethrowing or throwing a wrapper exception. Calls to the extra tasks and the thrown exception should be verified by a unit test. This means you have some […]
JGroups: Leader election without additional infrastructure
Hi there, in this post I’ll show how you can solve the problem of leader election without using any additional infrastructure like Apache Zookeeper or Consul. Leader election is a common way to solve the problem that in a distributed system only one instance must do a particular job. This could be for example triggering scheduled jobs […]
Combining the power of Gradle, Flyway and JOOQ for seamless development with databases
Hi there, in this post I will show you how easily you can combine the power of Gradle, with Flyway and JOOQ. At the end you will have a recipe for a build that automatically updates the models whenever you update your database. The problem When developing applications with database access, we usually face the problem, that we […]
Dependency Injection – Method call
Hi there, this is the second part of the article about (Dependency Injection – Field vs Constructor vs Method). In the comments I was hinted that I forgot to mention the 5th way of dependency injection, the injection of behavior when a method is called and I was asked if I can give some example when […]
Dependency Injection – Field vs Constructor vs Method
Hi, today I would like to discuss in short different ways of injecting dependencies into your classes. In general you have the following three options for injection directly into fields/attributes via explicit setter methods via explicit constructor parameters Field injection This type of injection instruments some kind of reflection mechanism for injecting the required dependencies into the class. […]
Strategies to migrate from an DAO library
In this post I will discuss several strategies to handle the following situation: You’re working on a legacy project that uses a company library with DBOs and DAOs for accessing the database. But the generator for this library is broken and you have to make changes to the DBOs and/or DAOs. Basic cases You will face the following three basic […]
Tutorial – Docker, JPA and Testing
Hi, a few weeks ago I attended the BED – Con. One of the talks I listened to, was about Docker (given by Dr. Halil-Cem Gürsoy). One of the ideas that came directly to my mind was, to use docker for creating separate instances of the finally used database for tests that can’t use databases like […]
Creating beautiful release notes with git, gradle and markdown
During the last days I asked myself how to generated releases notes from information that are available in commit / tag messages from git. The decisions My first approach was to create the list of changes directly from the commit messages, but this approach has multiple drawbacks. The commit messages must be written very disciplined […]
Released : CDIProperties – v.1.0.0
Inspired by the tutorial about writing CDI extensions I wrote several days ago I created a CDI extension which targets exactly this topic CDIProperties This handy library enables a CDI (in a standalone or application server environment) application to directly inject properties from a property file. It’s extensible via an SPI, so that you can […]