org.exolab.castor.mapping
Interface MapHandler

public interface MapHandler

A Map handler for adding and retreiving key-value pairs from A map. A map handler is instantiated only once, must be thread safe and not use any synchronization.

Version:

$Revision: 1.2 $ $Date: 2004/02/13 21:34:10 $

Author:

Keith Visco

Method Summary

void	clear(java.lang.Object map) Clears the map of all key-value pairs.
java.lang.Object	create() Creates a new Instance of the map represented by this MapHandler.
java.util.Enumeration	elements(java.lang.Object map) Returns an enumeration of all the objects in the Map.
java.lang.Object	get(java.lang.Object map, java.lang.Object key) Returns the object associated with the given key.
java.util.Enumeration	keys(java.lang.Object map) Returns an enumeration of all the keys in the Map.
java.lang.Object	put(java.lang.Object map, java.lang.Object key, java.lang.Object object) Adds the given key-value pair to the map.
int	size(java.lang.Object map) Returns the number of elements (key-value) in the map.

Method Detail

create

public java.lang.Object create()

Creates a new Instance of the map represented by this MapHandler.

Returns:

the new map.

put

public java.lang.Object put(java.lang.Object map,
                            java.lang.Object key,
                            java.lang.Object object)
                     throws java.lang.ClassCastException

Adds the given key-value pair to the map. Keys must be unique. Adding a key-value pair to the map, when an existing association for that key already exists will cause the existing association to be overwritten. The map is provided as a parameter and is returned as the return value if the returned map is a different object. That way the handler can create a new map if necessary.

Parameters:

map - the map, null if no map has been created yet.

key - the key for the object.

object - the object to add to the map.

Returns:

The map with the new object if a different instance than the map parameter, null otherwise

Throws:

java.lang.ClassCastException - The MapHandler does not support maps of the given type.

elements

public java.util.Enumeration elements(java.lang.Object map)
                               throws java.lang.ClassCastException

Returns an enumeration of all the objects in the Map.

Parameters:

map - The map instance for which to return the enumeration of elements for.

Returns:

An enumeration of all the elements in the Map.

Throws:

java.lang.ClassCastException - The MapHandler does not support collections of this type

keys

public java.util.Enumeration keys(java.lang.Object map)
                           throws java.lang.ClassCastException

Returns an enumeration of all the keys in the Map.

Parameters:

map - The map instance for which to return the enumeration of keys.

Returns:

An enumeration of all the keys in the Map.

Throws:

java.lang.ClassCastException - The MapHandler does not support collections of this type

size

public int size(java.lang.Object map)
         throws java.lang.ClassCastException

Returns the number of elements (key-value) in the map.

Parameters:

map - the map.

Returns:

Number of key-value associations in the Map

Throws:

java.lang.ClassCastException - The MapHandler does not support collections of the given type.

clear

public void clear(java.lang.Object map)
           throws java.lang.ClassCastException

Clears the map of all key-value pairs.

Parameters:

map - the map to clear.

Throws:

java.lang.ClassCastException - The MapHandler does not support collections of the given type.

get

public java.lang.Object get(java.lang.Object map,
                            java.lang.Object key)
                     throws java.lang.ClassCastException

Returns the object associated with the given key.

Parameters:

map - the map to return the object from.

key - the key for the object.

Returns:

the object associated with the given key, or null if no association was found in the given map.

Throws:

java.lang.ClassCastException - The MapHandler does not support maps of the given type.