org.exolab.castor.mapping.handlers

Class J2MapHandler

java.lang.Object

org.exolab.castor.mapping.handlers.J2MapHandler

All Implemented Interfaces:

MapHandler

public final class J2MapHandler
extends Object
implements 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: 5951 $ $Date: 2003-03-03 00:05:44 -0700 (Mon, 03 Mar 2003) $

Author:

Keith Visco

Constructor Summary

Constructors

Constructor and Description
J2MapHandler()

Method Summary

Methods

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

Methods inherited from class java.lang.Object

clone, equals, finalize, getClass, hashCode, notify, notifyAll, toString, wait, wait, wait

Constructor Detail

J2MapHandler

public J2MapHandler()

Method Detail

create

public Object create()

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

Specified by:

create in interface MapHandler

Returns:

the new map.

put

public Object put(Object map,
         Object key,
         Object object)
           throws 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.

Specified by:

put in interface MapHandler

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:

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

elements

public Enumeration elements(Object map)
                     throws ClassCastException

Returns an enumeration of all the objects in the Map.

Specified by:

elements in interface MapHandler

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:

ClassCastException - The MapHandler does not support collections of this type

keys

public Enumeration keys(Object map)
                 throws ClassCastException

Returns an enumeration of all the keys in the Map.

Specified by:

keys in interface MapHandler

Parameters:

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

Returns:

An enumeration of all the keys in the Map.

Throws:

ClassCastException - The MapHandler does not support collections of this type

size

public int size(Object map)
         throws ClassCastException

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

Specified by:

size in interface MapHandler

Parameters:

map - the map.

Returns:

Number of key-value associations in the Map

Throws:

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

clear

public void clear(Object map)
           throws ClassCastException

Clears the map of all key-value pairs.

Specified by:

clear in interface MapHandler

Parameters:

map - the map to clear.

Throws:

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

get

public Object get(Object map,
         Object key)
           throws ClassCastException

Returns the object associated with the given key.

Specified by:

get in interface MapHandler

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:

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