jsfcdiomnifaces

Get list all initialized @Named-beans on runtime


I use javax.inject.Named and javax.enterprise.context.*Scoped plus org.omnifaces.cdi.ViewScoped to define the life-scope of my view-beans.

Now I want to get a list of all instantiated beans. First, I thought this blog-entry covers this issue, but it only lists @ManagedBeans.

Do you know how to list them? Is this possible without being fixed on an implementation or even a version of JavaEE?

PS: I already found org.omnifaces.cdi.BeanStorage, but I don't have any idea how to access its map.


Solution

  • Given that you're using OmniFaces, you can use Beans#getActiveInstances() method of the Beans utility class to get all active instances in a given CDI scope.

    Map<Object, String> activeViewScopedBeans = Beans.getActiveInstances(ViewScoped.class);
    // ...
    

    The key is the bean instance and the value is the bean name.

    For the technically interested, here's the concrete implementation of this utility method:

    public static <S extends Annotation> Map<Object, String> getActiveInstances(BeanManager beanManager, Class<S> scope) {
        Map<Object, String> activeInstances = new HashMap<>();
        Set<Bean<?>> beans = beanManager.getBeans(Object.class);
        Context context = beanManager.getContext(scope);
    
        for (Bean<?> bean : beans) {
            Object instance = context.get(bean);
    
            if (instance != null) {
                activeInstances.put(instance, bean.getName());
            }
        }
    
        return Collections.unmodifiableMap(activeInstances);
    }
    

    The BeanStorage is for internal usage only. Moreover, it's not listed in the showcase.