biweekly.util

Class ListMultimap<K,V>

java.lang.Object

biweekly.util.ListMultimap<K,V>

Type Parameters:

K - the key

V - the value

All Implemented Interfaces:

Iterable<Map.Entry<K,List<V>>>

Direct Known Subclasses:

ICalParameters

public class ListMultimap<K,V>
extends Object
implements Iterable<Map.Entry<K,List<V>>>

A multimap that uses ArrayList objects to store its values. The internal Map implementation is a LinkedHashMap.

Author:

Michael Angstadt

Constructor Summary

Constructors

Constructor and Description
ListMultimap() Creates an empty multimap.
ListMultimap(int initialCapacity) Creates an empty multimap.
ListMultimap(ListMultimap<K,V> orig) Creates a copy of an existing multimap.
ListMultimap(Map<K,List<V>> map) Creates a new multimap backed by the given map.

Method Summary

Methods

Modifier and Type	Method and Description
Map<K,List<V>>	asMap() Gets an immutable view of the underlying Map object.
void	clear() Clears all entries from the multimap.
boolean	containsKey(K key) Determines whether the given key exists.
boolean	equals(Object obj)
V	first(K key) Gets the first value that's associated with a key.
List<V>	get(K key) Gets the values associated with the key.
Map<K,List<V>>	getMap() Gets the Map that backs this multimap.
int	hashCode()
boolean	isEmpty() Determines if the multimap is empty or not.
Iterator<Map.Entry<K,List<V>>>	iterator() Gets an iterator for iterating over the entries in the map.
Set<K>	keySet() Gets all the keys in the multimap.
void	put(K key, V value) Adds a value to the multimap.
void	putAll(K key, Collection<V> values) Adds multiple values to the multimap.
boolean	remove(K key, V value) Removes a particular value.
List<V>	removeAll(K key) Removes all the values associated with a key
List<V>	replace(K key, Collection<V> values) Replaces all values with the given values.
List<V>	replace(K key, V value) Replaces all values with the given value.
protected K	sanitizeKey(K key) Modifies a given key before it is used to interact with the internal map.
int	size() Gets the number of values in the map.
String	toString()
List<V>	values() Gets all the values in the multimap.

Methods inherited from class java.lang.Object

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

Constructor Detail

ListMultimap

public ListMultimap()

Creates an empty multimap.

ListMultimap

public ListMultimap(int initialCapacity)

Creates an empty multimap.

Parameters:

initialCapacity - the initial capacity of the underlying map.

ListMultimap

public ListMultimap(ListMultimap<K,V> orig)

Creates a copy of an existing multimap.

Parameters:

orig - the multimap to copy from

ListMultimap

public ListMultimap(Map<K,List<V>> map)

Creates a new multimap backed by the given map. Changes made to the given map will effect the multimap and vice versa.

To avoid problems, it is highly recommended that the given map NOT be modified by anything other than this ListMultimap class after being passed into this constructor.

Parameters:

map - the backing map

Method Detail

put

public void put(K key,
       V value)

Adds a value to the multimap.

Parameters:

key - the key

value - the value to add

putAll

public void putAll(K key,
          Collection<V> values)

Adds multiple values to the multimap.

Parameters:

key - the key

values - the values to add

get

public List<V> get(K key)

Gets the values associated with the key. Changes to the returned list will update the underlying multimap, and vice versa.

Parameters:

key - the key

Returns:

the list of values or empty list if the key doesn't exist

first

public V first(K key)

Gets the first value that's associated with a key.

Parameters:

key - the key

Returns:

the first value or null if the key doesn't exist

containsKey

public boolean containsKey(K key)

Determines whether the given key exists.

Parameters:

key - the key

Returns:

true if the key exists, false if not

remove

public boolean remove(K key,
             V value)

Removes a particular value.

Parameters:

key - the key

value - the value to remove

Returns:

true if the multimap contained the value, false if not

removeAll

public List<V> removeAll(K key)

Removes all the values associated with a key

Parameters:

key - the key to remove

Returns:

the removed values or an empty list if the key doesn't exist (this list is immutable)

replace

public List<V> replace(K key,
              V value)

Replaces all values with the given value.

Parameters:

key - the key

value - the value with which to replace all existing values, or null to remove all values

Returns:

the values that were replaced (this list is immutable)

replace

public List<V> replace(K key,
              Collection<V> values)

Replaces all values with the given values.

Parameters:

key - the key

values - the values with which to replace all existing values

Returns:

the values that were replaced (this list is immutable)

clear

public void clear()

Clears all entries from the multimap.

keySet

public Set<K> keySet()

Gets all the keys in the multimap.

Returns:

the keys (this set is immutable)

values

public List<V> values()

Gets all the values in the multimap.

Returns:

the values (this list is immutable)

isEmpty

public boolean isEmpty()

Determines if the multimap is empty or not.

Returns:

true if it's empty, false if not

size

public int size()

Gets the number of values in the map.

Returns:

the number of values

asMap

public Map<K,List<V>> asMap()

Gets an immutable view of the underlying Map object.

Returns:

an immutable map

getMap

public Map<K,List<V>> getMap()

Gets the Map that backs this multimap. This method is here for performances reasons. The returned map should NOT be modified by anything other than the ListMultimap object that owns it.

Returns:

the map

sanitizeKey

protected K sanitizeKey(K key)

Modifies a given key before it is used to interact with the internal map. This method is meant to be overridden by child classes if necessary.

Parameters:

key - the key

Returns:

the modified key (by default, the key is returned as-is)

iterator

public Iterator<Map.Entry<K,List<V>>> iterator()

Gets an iterator for iterating over the entries in the map. This iterator iterates over an immutable view of the map.

Specified by:

iterator in interface Iterable<Map.Entry<K,List<V>>>

Returns:

the iterator

toString

public String toString()

Overrides:

toString in class Object

hashCode

public int hashCode()

Overrides:

hashCode in class Object

equals

public boolean equals(Object obj)

Overrides:

equals in class Object