Code Soapbox Posts

June 25, 2019 / Java

If you’re using the springfox-swagger2 library, you might come across a problem when it comes to generic types (such as Pet<T>). In cases where diamond brackets are used, Swagger will generate an invalid specification, resulting in a validation error in the Swagger Editor (“”$ref values must be RFC3986-compliant percent-encoded URIs”).

May 11, 2019 / Clean code

The Liskov Substitution Principle, introduced by Barbara Liskov, represents the “L” in SOLID. It states that every implementation of a class should be replaceable with an implementation of any class that extends it. In other words, every instance of a parent class should be replaceable by any instance of its child classes so that the application continues to work.

May 9, 2019 / Clean code

The Open/Closed Principle represents the “O” in SOLID. In the words of Bertrand Meyer (who originated the term), it states that “software entities (classes, modules, functions, etc.) should be open for extension, but closed for modification“. What it means is that one should be able to extend the behavior of an entity without modifying its code.

January 13, 2019 / Clean code

The Single Responsibility Principle represents the “S” in SOLID. It means that a software module should only have one responsibility – in other words, there should never be more than one reason to modify that module (excluding, of course, refactoring and bug fixes). The responsibility of a module should be entirely encapsulated within that module and all services within it should be narrowly aligned with it.

October 12, 2018 / Java
August 9, 2018 / Link Bag
June 12, 2018 / Spring

By default, Spring Boot uses an OpenEntityManagerInViewInterceptor which “binds a JPA EntityManager to the thread for the entire processing of the request […] to allow for lazy loading in web views despite the original transactions already being completed”.

In other words, in every @Controller/@RestController action, instead of throwing a LazyInitializationException when you forget to fetch a lazy-loaded property, Spring will now fetch the property outside of the original transaction. The pattern (or antipattern) is called Open Session In View (OSIV) and, while it sounds fairly useful, is not a good choice for production environments.

March 14, 2018 / Rants
February 14, 2018 / Design patterns

The Builder pattern helps us create complex objects that can have different representations, simplifying the process and (optionally) preserving immutability – encapsulating the code responsible for assembling an object in a separate Builder class.

In simpler terms, it delegates the responsibility of creating a complex object to its Builder, whose job it is to make sure that the object is never created in an invalid state.

January 25, 2018 / Link Bag