Victor Rentea | The Blog Pros

February 18, 2022

Design Insights From Unit Testing

Probably the biggest breakthrough while Unit Testing is to realize that writing tests offer priceless feedback about the design of your production code. This feedback goes from suggesting immediate obvious improvements, up to hints about some of the most advanced design principles in software engineering. This article briefly enumerates these hints, pointing to questions to ask about your design.

Disclaimer: Don't follow blindly these hints, but make sure you understand all of them so that you can decide in your real problem what would improve the design, and what wouldn't.

February 18, 2022

Control Your Data Structures

Complex logic should be implemented on data structures you have full control on an internal Domain Model that you can tailor to your problem to simplify your code.

Here is an (opinionated) list of term definitions used in this article:

January 12, 2021

Presenting Exceptions to Users

This article was originally posted at https://victorrentea.ro/blog/presenting-exceptions-to-users/

The Author: Victor Rentea is a Java Champion, Independent Trainer, and founder of one of the largest developer communities in his country. After training thousands of developers in dozens of companies throughout the world, he now shares best practices with hundreds of teams. You can read more about him on victorrentea.ro.

December 17, 2020

Avoiding NullPointerException

The terrible NullPointerException (NPE in short) is the most frequent Java exception occurring in production, according to a 2016 study. In this article, we'll explore the main techniques to fight it: the self-validating model and the Optional wrapper.

Self-Validating Model

Imagine a business rule: every Customer has to have a birth date set. There are a number of ways to implement this constraint: validating the user data on the create and update use-cases, enforcing it via NOT NULL database constraint and/or implementing the null-check right in the constructor of the Customer entity. In this article, we'll explore the last one.

December 10, 2020

Functional Programming Patterns With Java 8

It’s been four years since functional programming became feasible in Java. The means we have had four years to play with Java 8.

And we've played... and played. After developing several large enterprise projects that made heavy use of Lambdas and Streams, consulted many other projects in doing so, and taught these concepts to hundreds of developers as an independent trainer, I think it’s time to summarize patterns, best practices, and anti-patterns.