Hands-On High Performance with Spring 5

Setter-based DI

In a constructor-based DI, we saw a dependent object injecting through a constructor argument. In a setter-based DI, the dependent object is provided by a setter method in the dependent class. Setter-based DI is accomplished by calling setter methods on beans after invoking no-args constructors through the container.

In the following code, we show how to use a setter method for injecting a CustomerService object in the BankingService class:

@Componentpublic class BankingService {  private CustomerService customerService;    // Setter-based Dependency Injection  @Autowired  public void setCustomerService(CustomerService customerService) {  this.customerService = customerService;  }  public void showCustomerAccountBalance() { customerService.showCustomerAccountBalance(); ...