[Spring] Setter Injection

세터 인젝션이란?

• 세터 매서드로 dependencies 주입

Aturowiring Example

• Inejecting a Coach implementation

• Spring will scan for @Components

• Any one implements the Coach imterface??

• If so, let’s inject them. For example: CricketCoach

Development Process - Setter Injection

1. Create setter method(s) in your class for injections

2. Configure the dependency injection with @Autowired Annotation

Step 1: Create setter method(s) in your class for injections

File: DemoController.java

public class DemoController {

    private Coach myCoach;

    public void setCoach(Coach theCoach){

        myCoach = theCoach;
}
}

Step 2: Configure the dependency injection with Autowired Annotation

File: DemoController.java

public class DemoController {

File: DemoController.java

public class DemoController {

    private Coach myCoach;

    @Autowired
    public void setCoach(Coach theCoach){

        myCoach = theCoach;
}
}

Injection Types - Which one to use?

• Constructor Injection

  • Use this when you have required dependencies

  • Generally recommended by the spring.in development team as first choice

• Setter Injection

  • Use this when you have optional dependencies

  • If dependency is not provided, your app can provide reasonable default logic