When should setter injection be used?
Use Setter injection when a number of dependencies are more or you need readability. Use Constructor Injection when Object must be created with all of its dependency.
What is setter injection?
Setter Injection in Spring is a type of dependency injection in which the framework injects the dependent objects into the client using a setter method. The container first calls the no argument constructor and then calls the setters.
Why are setter injections bad?
The reasons why field injection is frowned upon are as follows: You cannot create immutable objects, as you can with constructor injection. Your classes have tight coupling with your DI container and cannot be used outside of it. Your classes cannot be instantiated (for example in unit tests) without reflection.
How does setter injection work?
Spring Setter Injection is nothing but injecting the Bean Dependencies using the Setter methods on an Object. Unlike Spring Constructor Injection, in Setter Injection, the object is created first and then the dependency is injected. Consider, we have a DogsService, which is a Spring based REST Service.
Which is better constructor injection or setter injection?
Overriding: Setter injection overrides the constructor injection. If we use both constructor and setter injection, IOC container will use the setter injection. It doesn’t create a new bean instance always like constructor. So setter injection is flexible than constructor injection.
What are the benefits of dependency injection?
Dependency Injection Benefits
- Reduced Dependencies.
- Reduced Dependency Carrying.
- More Reusable Code.
- More Testable Code.
- More Readable Code.
Why constructor injection is better than setter injection?
A constructor therefore enforces the dependency requirement whether or not you’re using Spring, making it container-agnostic. If you use setter injection, the setter may or may not be called, so the instance may never be provided with its dependency.
Which is the best dependency injection in Spring?
Constructor Injection This is the best method we have looked at so far. When using a constructor to set injected properties, you do not have to provide the autowire annotation.
Why should I use DI?
The main reason to use DI is that you want to put the responsibility of the knowledge of the implementation where the knowledge is there. The idea of DI is very much inline with encapsulation and design by interface.
What are the disadvantages of dependency injection?
Disadvantages of Dependency Injection:
- Dependency injection creates clients that demand configuration details to be supplied by construction code.
- Dependency injection can make code difficult to trace (read) because it separates behaviour from construction.
- It requires more upfront development effort.