I will continue with using the AlertService from part 2 of the series, to show how to utilise Dependency Injection in Spring with a more common situation. Let us start with the MessageServices and bring them under control of the BeanFactory in Spring by annotating them as a Component. @Component public class EmailMessageService implements MessageService...
Inversion of Control – Part III – Dependency Injection in Java Spring I
As I explained in the blog post about Inversion of Control, your code can be controlled not only by implementing an IoC Design Pattern within your code, by a framework that controls (part of) your code, but also by an entity, that you don’t have direct control over, such as a Servlet Container that...
Inversion of Control – Part II – Dependency Injection
In the first part, I described what Inversion of Control (IoC) is and how it can be implemented using the classical GoF design patterns. In this post, I will explain another implementation of IoC: Dependency Injection. I assume that you are familiar with programming to an interface (or abstract class) rather than classes, as you...
Inversion of Control – Part I
Why am I talking about Inversion of Control? I will use Spring (Boot) later on to build services. Spring is based on Dependency Injection. Dependency Injection is one possible implementation of Inversion of Control. Hence, it is reasonable to understand the basics of Inversion of Control (IoC) and how it can be implemented. Before...