Create Bean programmatically

[alexanderbell]

Hi,

I want to retrieve a Bean with a given Type programmatically.
Until now I use this way:

BeanManager manager = CurrentManager.rootManager();
Set<Bean<?>> beans = manager.getBeans(MyService.class);
if(beans != null && beans.size() == 1) {
    Bean<?> bean = beans.iterator().next();
    Object serviceObject = manager.getReference(bean, MyService.class);
    return serviceObject;
} else {
    ...
}

I use the serviceObject and afterwards I wanna destroy it because I want that all dependent objects are destroyed and all disposer methods are called.
I've found a method called javax.enterprise.inject.spi.Bean.destroy.
But this method needs a CreationalContext as one of its parameters.
So what is a CreationContext and where can I get one?

Maybe there's another way to get a Bean programmatically and destroy it afterwards.

Alex

[pmuir]

You should use:

@Current Instance<Object> myService;
myService.select(MyService.class).doFoo();

then the container will do the cleanup for you.

[alexanderbell]

Unfortunately I cannot use the @Current annotation in my class because it isn't created by the WebBeans Manager.
So I have to do in in a full programmatically manner.

Any ideas?

[niravshah]

Am using a similar kind of programatic creation of beans (since my base class is not manager created).
Here's the code. Hope it helps.

 Set<Bean<CieResource>> beans = manager.resolveByType(CieResource.class, new AnnotationLiteral<CieStandardProvBT>(){});
  for(Bean<CieResource> discoveredResource : beans) 
        {
            
            CieResource resource = discoveredResource.create(new CreationalContextImpl<CieResource>(discoveredResource));
            resource.register(this);
        }

Cheers!
Nirav

[alexanderbell]

Unfortunately CreationalContextImpl is a WebBeans specific class.
IMO there have to be an API for creating and destroying beans programmatically
In the previous spec. there was a method for creating Beans in the BeanManager API. Unfortunately I don't know the name of the method anymore.

@Pete
Do u know a better way for that case?

[pmuir]

Alexander Bell wrote on Jul 09, 2009 14:24:


Unfortunately I cannot use the @Current annotation in my class because it isn't created by the WebBeans Manager.
So I have to do in in a full programmatically manner.

Any ideas?

What is the class created by?

In the PFD you would do:

manager.createInjectionTarget(type).inject(instance, manager.createCreationalContext(null));

NB implementing this is on my todo list this week.

[alexanderbell]

The object is created by Axis (it's the ServiceMessageReceiver).
After reading some webbeans-code I chose this way:

BeanManagerImpl manager = CurrentManager.rootManager();
Set<Bean<?>> beans = manager.getBeans(serviceClass);
if(beans != null && beans.size() == 1) {
        Bean<?> bean = beans.iterator().next();
        CreationalContext<?> creationalCtx = CreationalContextImpl.of(bean);
        Object serviceObject = manager.getInjectableReference(bean, creationalCtx);
        return serviceObject;
...

The serviceObject and CreationalContext are saved in the AxisServiceContext.

Code for disposing

bean.destroy(serviceObject, creationalCtx);

I've got two more questions ;-)
What is a PFD?
What is the meaning of CreationalContext?

Alex

[pmuir]

Basically, that is correct, except that you should switch to using non-contextual injection once available in CR1. I wrote an FAQ for you http://www.seamframework.org/Documentation/HowDoIDoNoncontextualInjectionForAThirdpartyFramework.

PFD is the proposed final draft of the spec (which is currently published). CreationalContext is a context associated with instance creation and destruction.

[alexanderbell]

Thanks Pete

[pmuir]

BTW InjectionTarget is implemented in trunk :-)