How to instantiate a session scoped bean without creating a reference to it?

Question

I have a websocket scoped bean that do something everytime that a new session is created. The problem is that this bean use some observable handlers, it's not called directly, so the bean is never instantiated.

How do I instantiate a websocket scoped bean without making a direct acces to it?

Answer 1

My solution:

Create an interface to use on the components that you want to be initialized:

public interface WebSocketSessionPrematureInitialization {
    default void initialize() {}
}

Create a component to initialize all the components that implements the interface:

@Component
@Scope(scopeName = "websocket", proxyMode = ScopedProxyMode.TARGET_CLASS)
public class WebSocketBeanInitializer {

    private final List<? extends WebSocketSessionPrematureInitialization> wsInit;

    @Autowired
    public WebSocketBeanInitializer(List<? extends WebSocketSessionPrematureInitialization> wsInit) {
        this.wsInit = wsInit;
    }

    public void initialize() {
        for (WebSocketSessionPrematureInitialization bean : wsInit)
            bean.initialize();
    }

}

Now you just need to call the initialize() method of the WebSocketBeanInitializer always that a new session is created.