JBossDeveloper

Martin Kouba escreveu:

By the way, I don't know why Weld doesn't implement this. It is in the specification, so it is not going agains anything here. What's the point of a CDI provider to retain a lost instance in memory if it's not used anywhere else?

Because if you have a dependent bean with @PreDestroy callback you can't simply use a java.lang.ref.WeakReference - the container is required to destroy the bean instance correctly. I'm not aware of any reliable way of doing this in Java. But I'm ready to explore any tips

Yes, you're right. This is a real impediment. Thinking better now, if the @PreDestroy was the only reason for the impediment, I could live without it in my dependent beans, but not without transitive dependencies.

Martin Kouba escreveu:

 

If these dependencies are normal scoped or dependent without @PreDestroy/disposer you should be fine too (I mean transitivity requirement should only apply to dependent dependencies hierarchy, but I'm not 100% sure). Anyway, it's just an optimization - nothing you should rely on.

I created this simple proof of concept test:

public class MyBean1

{

    @Inject

    private MyBean2 _myBean2;

    @Override

    protected void finalize() throws Throwable

    {

        super.finalize();

        System.out.println("MyBean1 released");

    }

}

public class MyBean2

{

    @Override

    protected void finalize() throws Throwable

    {

        super.finalize();

        System.out.println("MyBean2 released");

    }

}

private void shortLivedMethod()

{

    CDI.current().select(MyBean1.class).get();

    Timer timer = new Timer(true);

    timer.schedule(

        new TimerTask()

        {

            @Override

            public void run()

            {

                System.gc();

            }

        },

        2000, 3000

    );

}

And it really worked as you said: with no @PreDestroy method, the dependent beans were released by CDI (the messages were printed on the console). Just wondering: does this still work if I apply interceptors and decorators to the dependent beans? Can you tell me something about this? (I think we're almost there).

I've just checked with interceptors: it didn't work. I applied an interceptor to the MyBean class and the bean was not released automatically by CDI anymore. I suppose the same is true for decorators and even events.