What is the BeanContextMembershipEvent Notification?

[sivaranjan]

Hi friends,
Last time you all guys helped me a lot for solving mu issue. So I thought that posting here my query would be helpful. I have recently started doing the Beans Context. In that I am unable to understand about the BeanContextMembershipEvent.!! So can anyone out there explain me what is the BeanContextMembershipEvent Notification.?? Expecting the needful solution sooner.!!

[MindSpace]

The BeanContext API uses the standard Java event model to register listeners and deliver events. A BeanContextMembershipEvent encapsulates the list of children added to, or removed from, the membership of a particular BeanContext. An instance of this event is fired whenever a successful add(), remove(), retainAll(), removeAll(), or clear() is invoked on a given BeanContext instance. Objects interested in receiving events of this type must implement the BeanContextMembershipListener interface

[opaper]

Compliant BeanContexts fire events on this interface when the state of the membership of the BeanContext changes. The method childrenAdded is called when a child or list of children is added to a BeanContext that this listener is registered with. The following shows an example of the same :

void childrenAdded(BeanContextMembershipEvent bcme)

[CodGuru]

I thought that providing code would be useful for you to understand. So I have given the following code that is the sample code of BeanContextMembershipEvent Notification :

import java.beans.beancontext.*;

public class MembershipDemo {
    public static void main(String[] args) {
        BeanContextSupport context = new BeanContextSupport(); 
        MyMembershipListener listener = new MyMembershipListener(); 
        BeanContextChildSupport bean = new BeanContextChildSupport(); 
        context.addBeanContextMembershipListener(listener); 
        context.add(bean);
        context.remove(bean);
    }
}

class MyMembershipListener implements BeanContextMembershipListener {
    public void childrenAdded(BeanContextMembershipEvent bcme) {
        System.out.println("Another bean has been added to the context.");
    }

    public void childrenRemoved(BeanContextMembershipEvent bcme) {
        System.out.println("A bean has been removed from the context.");
    }
}

[Praetor]

I have given you the coding of the same example described by the 'CodGuru' but i have implemented using an anonymous inner class :

import java.beans.beancontext.*;

public class MembershipDemo {
    public static void main(String[] args) {
        BeanContextSupport context = new BeanContextSupport();
        context.addBeanContextMembershipListener(new BeanContextMembershipListener() {
            public void childrenAdded(BeanContextMembershipEvent bcme) {
                System.out.println("Another bean has been added to the context.");
            }

            public void childrenRemoved(BeanContextMembershipEvent bcme) {
                System.out.println("A bean has been removed from the context.");
            }
        });
        BeanContextChildSupport bean = new BeanContextChildSupport();
        context.add(bean);
        context.remove(bean);
    }
}