Spring 使用构造函数在配置中进行延迟初始化

Question

I have a component

@Component
public class ExpenseCalculator {
    @Autowired
    private TaxService taxService;

    @Autowired
    private EmployeeService employeeService;

    @Autowired
    @Lazy
    private PurchaseService purchaseService;
}

Here PurchaseService is initialized only when any part of the code that uses purchaseService is invoked (?).

Now I have to move ExpenseCalculator a configuration class (it doesn't have @Component annotation)

@Configuration
public class ExpenseConfig {
    @Bean
    @Lazy
    public ExpenseCalculator getExpenseCalculator(
        TaxService taxService, 
        EmployeeService employeeService,
        PurchaseService purchaseService
    ) {
        return new ExpenseCalculator(taxService, employeeService, purchaseService);
    }
} 

But purchaseService is no more a @Lazy component when ever ExpenseCalculator is initialized, purchaseService get initialized.

Is there any way to get lazy initialization of purchaseService using configuration ?

Answer 1

You must annotate your PurchaseService with @Lazy in both places - where you create them and when you autowire them. See https://www.baeldung.com/spring-lazy-annotation#2-with-autowired , comment: "Note, that the @Lazy is mandatory in both places."