Dependency Injection and control inversion

Dependency Injection:

Class A relies on Class B, as follows:

Public a{

Private b b;

public void Showb () {

b= new B ();

System.out.println (b);

}

}

We can inject dependency classes by spring configuration or annotations, so that we do not have to instantiate dependent classes manually each time we use a dependent class, which is called dependency injection.

Control inversion:

We use the spring-provided ApplicationContext object (representing a spring control reversal container) to control the classes in the container, instead of creating classes to manipulate classes ourselves, which is control inversion.

Dependency Injection and control inversion