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

      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