```
public interface CollectionHandler
```
Collection handler for adding/listing elements of a collection. A collection field will use this handler to add elements when it's value is set, and to enumerate then when it's value is retrieved. A collection handler is instantiated only once, must be thread safe and not use any synchronization.

Version:

$Revision: 5951 $ $Date: 2003-03-03 00:05:44 -0700 (Mon, 03 Mar 2003) $

Author:

Assaf Arkin

Method Summary

All Methods Instance Methods Abstract Methods
Modifier and Type	Method	Description
`java.lang.Object`	`add(java.lang.Object collection, java.lang.Object object)`	Add an object to the collection.
`java.lang.Object`	`clear(java.lang.Object collection)`	Clears the collection of any objects.
`java.util.Enumeration`	`elements(java.lang.Object collection)`	Returns an enumeration of all the elements in the collection.
`int`	`size(java.lang.Object collection)`	Returns the number of elements in the collection.

- Method Detail
  - add
```
java.lang.Object add(java.lang.Object collection,
                     java.lang.Object object)
              throws java.lang.ClassCastException
```
    Add an object to the collection. A collection may not allow the same object to be added more than once. The collection is provided as a parameter and is returned as the return value if the returned collection is a different object. That way the handler can create a new collection or change the collection as necessary (e.g. when resizing an array).
    
    Parameters:
    
    collection - The collection, null if no collection has been created yet
    
    object - The object to add to the collection
    
    Returns:
    
    The collection with the new object if a different instance than the collection parameter, null otherwise
    
    Throws:
    
    java.lang.ClassCastException - The collection handler does not support collections of this type
  - elements
```
java.util.Enumeration elements(java.lang.Object collection)
                        throws java.lang.ClassCastException
```
    Returns an enumeration of all the elements in the collection.
    
    Parameters:
    
    collection - The collection
    
    Returns:
    
    An enumeration of all the elements in the collection
    
    Throws:
    
    java.lang.ClassCastException - The collection handler does not support collections of this type
  - size
```
int size(java.lang.Object collection)
  throws java.lang.ClassCastException
```
    Returns the number of elements in the collection.
    
    Parameters:
    
    collection - The collection
    
    Returns:
    
    Number of elements in the collection
    
    Throws:
    
    java.lang.ClassCastException - The collection handler does not support collections of this type
  - clear
```
java.lang.Object clear(java.lang.Object collection)
                throws java.lang.ClassCastException
```
    Clears the collection of any objects. The collection is provided as a parameter and is returned as the return value if the returned collection is a different object. That way the handler can create a new collection or change the collection as necessary (e.g. when resizing an array).
    
    Parameters:
    
    collection - The collection, null if no collection has been created yet
    
    Returns:
    
    The empty collection if a different instance than the collection parameter, null otherwise
    
    Throws:
    
    java.lang.ClassCastException - The collection handler does not support collections of this type

Interface CollectionHandler

Method Summary

Method Detail

add

elements

size

clear