What is the Bean Context : Containment Only?

[NGV BalaKrishna]

Hi friends,
I have done little bit of things in Java Beans. But I am confused in Bean Context. There are some types of the Bean Contexts. I have recently started learning about it, so don't have enough idea about it. So thought posting here would help me..!! Please tell me what is the Bean Context : Containment Only? Hope that someone would help me as soon as possible.!!

[Deabelos]

The "containment" portion of the Extensible Runtime Containment and Services Protocol is defined by the BeanContext interface. We basically use a BeanContext to logically group a set of related java beans, bean contexts, or arbitrary objects. JavaBeans nested into a BeanContext are known as "child" beans. Once nested, a child bean can query its BeanContext for various membership information.

[MELTRONICS]

With a BeanContextSupport instance, it is possible to :

• You can add an object, bean, or BeanContext: boolean add(Object o).
• You can remove an object, bean, or BeanContext: boolean remove(Object o).
• You can also add a BeanContextMembershipListener: void addBeanContextMembershipListener(BeanContextMembershipListener bcml).
• You can also remove a BeanContextMembershipListener: void removeBeanContextMembershipListener(BeanContextMembershipListener bcml).
• You can get the number of children currently nested in this BeanContext: int size().
• Determine whether or not the BeanContext currently has zero children: boolean isEmpty().

[kyosang]

After looking at the coding, I think that you can understand more better, so i have provided you with an example :

import java.beans.beancontext.*;

public class BeansEx {
    private static BeanContextSupport context = new BeanContextSupport(); 
    private static BeanContextChildSupport bean = new BeanContextChildSupport();
  
    public static void main(String[] args) {
        report();  

        System.out.println("Adding bean to context...");
        context.add(bean);

        report();
    }

    private static void report() {
        System.out.println("-------------");

        System.out.println("Is the context empty? " + context.isEmpty());

        boolean result = (bean.getBeanContext()!=null);
        System.out.println("Does the bean have a context yet? " + result);

        System.out.println("Number of children in the context: " + context.size());

        System.out.println("Is the bean a member of the context? " + context.contains(bean));

        if (bean.getBeanContext() != null) {
            boolean isEqual = (bean.getBeanContext()==context); // true means both references point to the same object
            System.out.println("Contexts are the same? " + isEqual);
        }
        System.out.println("-----------------");   
    }
}

[MindSpace]

I also have given an example that may help you :

import java.beans.beancontext.*;

public class BeansTrial {
    public static void main(String[] args) {

        BeanContextSupport context = new BeanContextSupport(); 

        BeanContextChildSupport[] beans = new BeanContextChildSupport[100];

        System.out.println("Number of children in the context: " + context.size());

        for (int i = 0; i < beans.length; i++) {
            beans[i] = new BeanContextSupport();
            context.add(beans[i]);
        }
        System.out.println("Number of children in the context: " + context.size());

        Object[] children = context.toArray();
        System.out.println("Number of objects retrieved from the context: " + children.length);
    }
}