PostConstruct and PreDestroy of Bean

[nimo22]

I have something like this:

@SessionScoped @Named
public class A{

        @PersistenceContext EntityManager entityManager;

        @Inject B b;
        public B getB() {return b;}
        public void setB(B ob) {this.b = b;}

        @PostConstruct
        public void initialize()
        {
                System.out.println("@PostConstruct");
                System.out.println("Instance of B was constructed via inject.");
        }

        
           public void retrieveRecordsOfB(){

             b.setRecords(entityManager.createNamedQuery("getRec").getResultList());
        }

        @PreDestroy
        public void preDestroy()
        {
                System.out.println("@PreDestroy");
                System.out.println(this.getClass().getSimpleName() + " was destroyed.");
        }

}

and referred this bean in jsf-page:

<h:commandButton action="#{a.retrieveRecordsOfB}" value="retrieve"/>

I explored, that when viewing this page then the PreDestroy-Method is called even the session is not finished - why is the Instance of A instantly destroyed after it was constructed?

14:17:23,471 INFO  [STDOUT] @PostConstruct
14:17:23,471 INFO  [STDOUT] Instance of B was constructed via inject.
14:17:23,471 INFO  [STDOUT] @PreDestroy
14:17:23,471 INFO  [STDOUT] @PreDestroy A was destroyed

Another point is, that when clicking on retrieveRecordsOfB, then the database query is called twice (I guess, because of getter/setter). I have thought that this was solved in JSF2 or Weld?

[asiandub]

I'm observing the same behavior with a view-scoped bean (from seam-faces).

I vaguely remember that I've heard something about a related JBoss-AS-Bug in M4 (which is my setup), but basically I'd like to be sure about the reason.

so: bug or intention?

cheers,

jan

[asiandub]

oops: just to make sure - I'm referring to the @PreDestroy part of Nimo's posting.

Concerning the getter / setter part: ASFAIK, those are called multiple times because of the inherent JSF-lifecycle. This means that there is nothing to be resolved, it's just in the inherent nature of the technology....

[pmuir]

Sounds very weird, if you can reproduce in a simple cdi app (no seam etc), please file an issue :-)

[nimo22]

Hello,

the reason is found in:

http://seamframework.org/Community/BeansInjectReturnsNull

I had this

import javax.faces.bean.SessionScoped;

instead of this

import javax.enterprise.context.SessionScoped;

So I imported the jsf-scopes instead of the cdi-scopes.

Would be nice, if CDI would warn or returns an deployement-error,
if it detects a scope of a jsf-version instead of a scope of the cdi-version.

One should not be allowed to use the scope of a jsf-version in a CDI-Environment
- so this should return a deployement error (or at least a warning)!