A bridge between the ServletContext life cycle events and CDI observers (with example observer ApplicationInitializer)

ApplicationInitializer.java

// uncomment line if you want the instance to be retained in application scope
// @ApplicationScoped 
public class ApplicationInitializer
{
   public void onStartup(@Observes @Initialized ServletContext ctx)
   {
      System.out.println("Initialized web application at context path " + ctx.getContextPath());
   }
}

Destroyed.java

@Qualifier
@Retention(RetentionPolicy.RUNTIME)
@Target({ElementType.FIELD, ElementType.PARAMETER})
public @interface Destroyed {}

Initialized.java

@Qualifier
@Retention(RetentionPolicy.RUNTIME)
@Target({ElementType.FIELD, ElementType.PARAMETER})
public @interface Initialized {}

ServletContextLifecycleNotifier.java

@WebListener
public class ServletContextLifecycleNotifier implements ServletContextListener
{
   @Inject @Any
   private Event<ServletContext> servletContextEvent;
   
   @Override
   public void contextInitialized(ServletContextEvent sce)
   {
      servletContextEvent.select(new AnnotationLiteral<Initialized>() {}).fire(sce.getServletContext());
   }

   @Override
   public void contextDestroyed(ServletContextEvent sce)
   {
      servletContextEvent.select(new AnnotationLiteral<Destroyed>() {}).fire(sce.getServletContext());
   }
}

This was a really helpful solution to an issue I was trying to solve without using additional frameworks like Solder. Thanks Dan.

Very nice example. Thanks.

Hello,
the example does not work in WAS Liberty profile if I uncommon ApplicationScoped. I get:
org.apache.webbeans.event.ObserverMethodImpl I Cannot send event to bean in non-active context
probably because ApplicationScope is not yet initialised by the time the ServletContextListener. contextInitialized() method is invoked. Any workarounds? Thanks.