Hands-On High Performance with Spring 5

Constructor versus setter injection

As we can see, Spring supports three types of DI methods; however, field-based dependency is not recommended by Spring. So, constructor-based and setter-based DI are standard ways to injecting beans in your application. The selection of constructor or setter methods depends on your application requirements. In this table, we will see the different use cases of constructor and setter injection, and some best practices that will help us decide when to use setter injection over constructor injection, and vice versa:

Constructor injection	Setter injection
Best choice when the dependency is mandatory.	The suitable choice when the dependency is not mandatory.
Constructor injection makes the bean ...