org.datanucleus.util

Class MultiMap

java.lang.Object

java.util.AbstractMap<K,V>

java.util.HashMap

org.datanucleus.util.MultiMap

All Implemented Interfaces:

Serializable, Cloneable, Map

public class MultiMap
extends HashMap

An implementation of a MultiMap, which is basically a Map with multiple values for a key. This will be removed when SUN see sense and include it in the JDK java.util package as standard.

See Also:

Serialized Form

Nested Class Summary

Nested classes/interfaces inherited from class java.util.AbstractMap

AbstractMap.SimpleEntry<K,V>, AbstractMap.SimpleImmutableEntry<K,V>

Constructor Summary

Constructors

Constructor and Description
MultiMap() Constructor.
MultiMap(int initialCapacity) Constructor.
MultiMap(int initialCapacity, float loadFactor) Constructor.
MultiMap(MultiMap map) Constructor.

Method Summary

Methods

Modifier and Type	Method and Description
void	clear() Clear the map.
Object	clone() Method to clone the Map.
boolean	containsValue(Object value) Check if the map contains the passed value.
protected Collection	createCollection(Collection c) Creates a new instance of the map value Collection container.
Object	put(Object key, Object value) Add a key, and its value, to the map.
Object	remove(Object key, Object item) Removes a specific value from map.
Collection	values() Accessor for the values in the Map.

Methods inherited from class java.util.HashMap

containsKey, entrySet, get, isEmpty, keySet, putAll, remove, size

Methods inherited from class java.util.AbstractMap

equals, hashCode, toString

Methods inherited from class java.lang.Object

finalize, getClass, notify, notifyAll, wait, wait, wait

Methods inherited from interface java.util.Map

equals, hashCode

Constructor Detail

MultiMap

public MultiMap()

Constructor.

MultiMap

public MultiMap(int initialCapacity)

Constructor.

Parameters:

initialCapacity - the initial capacity

MultiMap

public MultiMap(int initialCapacity,
        float loadFactor)

Constructor.

Parameters:

initialCapacity - initial capacity

loadFactor - load factor for the Map.

MultiMap

public MultiMap(MultiMap map)

Constructor.

Parameters:

map - The initial Map.

Method Detail

containsValue

public boolean containsValue(Object value)

Check if the map contains the passed value.

Specified by:

containsValue in interface Map

Overrides:

containsValue in class HashMap

Parameters:

value - the value to search for

Returns:

true if the list contains the value

put

public Object put(Object key,
         Object value)

Add a key, and its value, to the map.

Specified by:

put in interface Map

Overrides:

put in class HashMap

Parameters:

key - the key to set

value - the value to set the key to

Returns:

the value added when successful, or null if an error

remove

public Object remove(Object key,
            Object item)

Removes a specific value from map. The item is removed from the collection mapped to the specified key.

Parameters:

key - the key to remove from

item - the value to remove

Returns:

the value removed (which was passed in)

clear

public void clear()

Clear the map.

Specified by:

clear in interface Map

Overrides:

clear in class HashMap

values

public Collection values()

Accessor for the values in the Map.

Specified by:

values in interface Map

Overrides:

values in class HashMap

Returns:

all of the values in the map

clone

public Object clone()

Method to clone the Map. Performs a shallow copy of the entry set.

Overrides:

clone in class HashMap

Returns:

the cloned map

createCollection

protected Collection createCollection(Collection c)

Creates a new instance of the map value Collection container.

Parameters:

c - the collection to copy

Returns:

new collection