@Component @Scope("singleton") public class BootStrapper implements ApplicationListener<ContextStartedEvent> {

Question

I am trying to do a one time initialization of my webapp. I need a singleton for the ApplicationListener class, so I set the scope to Singleton, but it is creating multiple instances. This BootStrapper is not defined in any other xml config files. I know that the default scope is singleton, but had to add @Scope("singleton") because it was not a singleton. Even with this annotation, it still creates multiple instances. Here is my ApplicationListener.

@Component
@Scope("singleton")
public class BootStrapper implements ApplicationListener<ContextRefreshedEvent> {

Am I missing anything?

Answer 1

To have a callback that is invoked after the bean is initialized, use @PostConstruct.

@Component
public class BootStrapper() {

     @PostConstruct
     public void doSomething() {
          System.out.println("I am initalized!");
     }
}