Interface CollectionHandler


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

    Modifier and Type
    Method
    Description
    add(Object collection, Object object)
    Add an object to the collection.
    clear(Object collection)
    Clears the collection of any objects.
    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 Details

    • add

      Object add(Object collection, Object 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 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