Some time ago I noticed new library in our code base - Random Beans which as the name suggests is a tool developed to easily create random data and random objects for testing purposes. Unfortunately, we used it in the wrong way. Here’s how we backed up from the random test data to regain control ove...

Some time ago I’ve been trying to dynamically create spring beans. After fast stackoverflow check I decided to drop it and go with something else. Lately I’ve been trying to implement more complicated bean registration mechanism in which skipping dynamic bean creation wasn’t an option. Here’s how yo...

Working with a lot of data using plain JPA or hibernate or spring-data is possible, it does work and usually, it doesn’t require a lot of extra coding. Starting small is the fastest way of getting things done but you must be aware of few things that might shoot you in the foot. Read more

Optimistic locking is concurrency control method that allows to execute multiple transactions simultaneously as long as they don’t interfere which each other. That’s definition from wikipedia. You probably already know that Hibernate supports optimistic locking and all you have to do in order to imp...

Immutability and functional programming are hot right now. But how to achieve immutability with objects deserialized from json? Luckily there is pretty old feature introduced in jackson 2.7.0 which uses constructor based object creation and uses @ConstructorProperties (introduced in java7). Read mor...

Every codebase depends on multiple external libraries. It is a good idea to stay up to date with external dependencies. It is important to update all security related stuff and it might be helpful or fun to use latest features. I’m going to share my way of staying up to date with external dependenci...

Page object pattern is common practice when writing automated tests using selenium. It allows to gather all possible operations on the page in one place and hide page implementation details from test case. Page object pattern can be used in the same way for angular directives, react and [put framewo...

When the project gets bigger and bigger there should be more and more tests. In the perfect world, all tests should be executed really fast, but life is far from perfect and sometimes some tests are slow. When using Gradle + Spock combination we have few ways of deciding how to group tests. I’m goin...

Private final field modification is possible and it doesn’t require a lot of work. Since you should not use this mechanism in real life there are cases when it is useful. For example this how is Hibernate using this to hydrate final entity fields. But when using final fields with Hibernate you shoul...

A few days ago I’ve stumbled upon SQL query performance issue. Git claims that I was the author so maybe that’s the reason I remember this feature. There was like 3 classes, everything was super easy and super fast all I needed to do was to let Hibernate do its thing. Then time passed, new features ...

Sometimes when unit tests setup is complex we are tempted to take shortcuts and write single setup for all tests which will save as few keystrokes. In the time of writing the test it might feel like a good idea to configure complex unit test setup and reuse it in all test. This way we avoid code dup...

HashCode and equals implementations are hard. Usually, it’s tricky to properly implement hashCode and equals method to fully fulfill contract from Java documentation. I’m going to focus on just one the point from the hashCode contract: whenever it is invoked on the same object more than once during ...

First post. It must be Hello world. I’m going to try and start posting something regularly. I’m Java and javascript so it’s probably will be the main topic of this blog. Sometimes I will try to write something more generic and not language specific. Read more