Dependency injection bean

Annotate the @Bean annotation to inject dependencies. Here's the content of GreetingConfigurationDIBean.kt:

@Configuration
open class GreetingConfigurationDIBean{
    @Bean
    open fun greeting(): GreetingDIBean {
        return GreetingDIBean(getUserDetails())
    }

    @Bean
    open fun getUserDetails(): GreetingDetailsDIBean {
        return GreetingDetailsDIBean()
    }
}

When two @Beans are dependent on each other, the dependency is as simplistic as having one bean method call another.

The content of GreetingDIBean.kt is as follows:

class GreetingDIBean (private val userDetails: GreetingDetailsDIBean){
    init {
        println("Inside DependenciesInjectBean.GreetingDIBean constructor.")
    }

    fun getGreeting() {
        userDetails.getGreetingDetails()
    }
}

The content of GreetingDetailsDIBean.kt is as follows:

class GreetingDetailsDIBean{
    init {
        println("This class has all the details of the user")
    }

    fun getGreetingDetails(){
        println("Welcome, Naruto Uzumaki!!")
    }
}

The content of MainApp.kt is as follows:

fun main(args: Array<String>) {
    val applicationContext = AnnotationConfigApplicationContext(GreetingConfigurationDIBean::class.java)

    val greeting = applicationContext.getBean(GreetingDIBean::class.java)
    greeting.getGreeting()
}

The result will be the following:

This class has all the details of the user
Inside Greeting constructor.
Welcome, Naruto Uzumaki!!