[weld-dev] ApplicationScoped event fires on service invocation

[Mark Struberg]

But the ServletContextEvent is available much earlier.
I think this might rather be an integration issue. 


In OWB we don't fire the @Intialized for the ApplicationContext inside the ApplicationContext implementation but as part of the integration code, means TomEE, Geronimo, SAP, etc.

The interplay and boot order between EJB @Startup @Singleton and the CDI container is imo not really well defined. We just did what we think is best. Afair that means that in TomEE we fire the @Initialized _before_ we do @Startup but _after_ all the metadata parsing and EJB and CDI Extension handling was done. 


LieGrue,
strub





> On Friday, 19 August 2016, 15:37, Martin Kouba <mkouba at redhat.com> wrote:
> > Hi Benjanmin,
> 
> for a web application the payload of 
> @Initialized(ApplicationScoped.class) must be the relevant 
> ServletContext. That's why Weld is waiting for a webapp to be ready 
> (implemented as 
> javax.servlet.ServletContextListener.contextInitialized(ServletContextEvent)).
> 
> Martin
> 
> Dne 19.8.2016 v 14:17 Benjamin Confino napsal(a):
>>  We have a user scenario where we wishes to replace @Singleton @Startup
>>  EJB beans with CDI beans. This was attempted by observing the
>>  ApplicationScoped initialization event to trigger the replacement code.
>> 
>>  However, the event was fired only after the service invocation, which
>>  was too late. Apparently OWB fires this event much earlier.
>>  The CDI spec states:
>> 
>>  The /application context /is provided by a built-in context object for
>>  the built-in scope type
>>  @ApplicationScoped. The application scope is active:
>>  • during the service() method of any servlet in the web application,
>>  during the doFilter()
>>  method of any servlet filter and when the container calls any
>>  ServletContextListener,
>>  HttpSessionListener, AsyncListener or ServletRequestListener,
>>  • during any Java EE web service invocation,
>>  • during any remote method invocation of any EJB, during any
>>  asynchronous method invocation
>>  of any EJB, during any call to an EJB timeout method and during message
>>  delivery to any EJB
>>  message-driven bean,
>>  • when the disposer method or @PreDestroy callback of any bean with any
>>  normal scope other
>>  than @ApplicationScoped is called, and
>>  *• during **@PostConstruct **callback of any bean.*
>> 
>>  The application context is shared between all servlet requests, web
>>  service invocations, EJB
>>  remote method invocations, EJB asynchronous method invocations, EJB
>>  timeouts and message
>>  deliveries to message-driven beans that execute within the same
>>  application. The application
>>  context is destroyed when the application is shut down.
>> 
>>  An event with qualifier @Initialized(ApplicationScoped.class) is fired
>>  when the application
>>  context is initialized and an event with qualifier
>>  @Destroyed(ApplicationScoped.class) is fired
>>  when the application is destroyed. The event payload is:
>>  • the ServletContext if the application is a web application deployed to
>>  a Servlet container, or
>>  • any java.lang.Object for other types of application.
>> 
>>  How do you interpret "initialized"? Does it mean the event is 
> fired only
>>  after the context is *active?*
>> 
>>  Is it possible to make the event firing a bit earlier, say around
>>  AfterDeploymentValidation?
>> 
>>  Below is the app to demonstrate the timing along with the server.xml:
>> 
>> 
>> 
>> 
>>  And here is the results of running it
>> 
>> 
>>  [AUDIT   ] CWWKE0001I: The server defaultServer has been launched.
>>  [AUDIT   ] CWWKE0100I: This product is licensed for development, and
>>  limited production use. The full license terms can be viewed here:
>> 
> https://public.dhe.ibm.com/ibmdl/export/pub/software/websphere/wasdev/license/base_ilan/ilan/16.0.0.2/lafiles/en.html
>> 
>>  [AUDIT   ] CWWKZ0058I: Monitoring dropins for applications.
>>  *---> ApplicationScopedExtension, AfterDeploymentValidation event
>>  received, before looking up and touching @ApplicationScoped dummy bean*
>>  *---> ApplicationScopedDummyBean, @PostConstruct init method called*
>>  *---> ApplicationScopedExtension, after looking up and touching
>>  @ApplicationScoped dummy bean*
>>  [AUDIT   ] CWWKT0016I: Web application available (default_host):
>>  http://localhost:9080/70383.180.846.test-application/
>>  *---> ApplicationScopedObserverBean, observed
>>  @Initialized(ApplicationScoped.class) event.*
>>  [AUDIT   ] CWWKZ0001I: Application 70383.180.846.test-application
>>  started in 1.165 seconds.
>>  [AUDIT   ] CWWKF0012I: The server installed the following features:
>>  [jsp-2.3, ejbLite-3.2, managedBeans-1.0, jsf-2.2, beanValidation-1.1,
>>  servlet-3.1, ssl-1.0, jndi-1.0, jsonp-1.0, appSecurity-2.0, jdbc-4.1,
>>  jaxrs-2.0, jaxrsClient-2.0, el-3.0, json-1.0, cdi-1.2,
>>  distributedMap-1.0, webProfile-7.0, websocket-1.1, jpa-2.1].
>>  [AUDIT   ] CWWKF0011I: The server defaultServer is ready to run a
>>  smarter planet.
>> 
>>  As you can see, the *ApplicationScopedDummyBean, @PostConstruct init
>>  method called*proves that the applicationContext was active before the
>>  event was fired. Why is this applicationscoped initialization event not
>>  fired earlier?
>> 
>> 
>>  Regards
>>  Benjamin
>>  Unless stated otherwise above:
>>  IBM United Kingdom Limited - Registered in England and Wales with number
>>  741598.
>>  Registered office: PO Box 41, North Harbour, Portsmouth, Hampshire PO6 3AU
>> 
>>  Unless stated otherwise above:
>>  IBM United Kingdom Limited - Registered in England and Wales with number
>>  741598.
>>  Registered office: PO Box 41, North Harbour, Portsmouth, Hampshire PO6 3AU
>> 
>> 
>>  _______________________________________________
>>  weld-dev mailing list
>>  weld-dev at lists.jboss.org
>>  https://lists.jboss.org/mailman/listinfo/weld-dev
>> 
> 
> -- 
> Martin Kouba
> Software Engineer
> Red Hat, Czech Republic
> 
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