Is there something like a ServletContextListener in JSF?

问题

I would like to listen if a JSF application is started or stopped like as possible with a ServletContextListener in a plain Servlet web application. How can I achieve this?

回答1:

You can use an @ApplicationScoped @ManagedBean which is eagerly initialized and annotate the desired startup/shutdown hook methods with @PostConstruct and @PreDestroy respectively.

So:

@ManagedBean(eager=true)
@ApplicationScoped
public class App {

    @PostConstruct
    public void init() {
        // ...
    }

    @PreDestroy
    public void destroy() {
        // ...
    }

}

---

Please note that this does not mean that you can't use a ServletContextListener in a JSF webapp. JSF is built on top of the Servlet API which thus means that you could just continue using it. With the new Servlet 3.0 @WebListener annotation, it's also possible to configure it without need for web.xml:

@WebListener
public class Config implements ServletContextListener {

    @Override
    public void contextInitialized(ServletContextEvent event) {
        // ...
    }

    @Override
    public void contextDestroyed(ServletContextEvent event) {
        // ...
    }

}

回答2:

You could provide a system event listener for this. See this blogpost for further details: Bootstrapping JSF applications with system events

来源：https://stackoverflow.com/questions/12177795/is-there-something-like-a-servletcontextlistener-in-jsf