org.exolab.castor.mapping

Interface CollectionHandler<T>

All Known Implementing Classes:

ArrayCollectionHandler, ArrayListCollectionHandler, CollectionCollectionHandler, EnumerateCollectionHandler, HashtableCollectionHandler, IteratorCollectionHandler, ListCollectionHandler, MapCollectionHandler, QueueCollectionHandler, SetCollectionHandler, SortedMapCollectionHandler, SortedSetCollectionHandler, VectorCollectionHandler

public interface CollectionHandler<T>

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:

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

Author:

Assaf Arkin

Method Summary

Modifier and Type	Method and Description
Object	add(Object collection, T object) Add an object to the collection.
Object	clear(Object collection) Clears the collection of any objects.
Enumeration<T>	elements(Object collection) Returns an enumeration of all the elements in the collection.
int	size(Object collection) Returns the number of elements in the collection.

Method Detail

add

Object add(Object collection,
           T object)
    throws 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:

ClassCastException - The collection handler does not support collections of this type

elements

Enumeration<T> elements(Object collection)
                 throws 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:

ClassCastException - The collection handler does not support collections of this type

size

int size(Object collection)
  throws ClassCastException

Returns the number of elements in the collection.

Parameters:

collection - The collection

Returns:

Number of elements in the collection

Throws:

ClassCastException - The collection handler does not support collections of this type

clear

Object clear(Object collection)
      throws 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:

ClassCastException - The collection handler does not support collections of this type