Managing the Spring context

The Spring application context is where our beans are referenced to be used in our application, and managing it correctly is not a simple task. When we have dozens of beans created, where and how we access them is important, and we could end up in a situation that we refer to as an incorrect bean.

In this section, we will discuss ways to handle this complexity.

Constructor injection

In this book, we have used @Autowired in our examples to illustrate how we ask Spring to inject a bean into our application.

Consider this example of two services and a controller that uses them:

import org.springframework.beans.factory.annotation.Autowired
import org.springframework.stereotype.Service
import org.springframework.web.bind.annotation.*

@Service
class AccountService {
  fun getAccountsByCustomer(customerId: Int): List<Account>
      = listOf(Account(1, 125F), Account(2, 500F))
}

@Service
class CustomerService {
  @Autowired
  private lateinit var accountService: AccountService...