Package org.eclipse.epsilon.common.util

Class Multimap<K,V>

java.lang.Object

org.eclipse.epsilon.common.util.Multimap<K,V>

Type Parameters:

K - The key type.

V - The type of values.

All Implemented Interfaces:

Map<K,Collection<V>>

public class Multimap<K,V>
extends Object
implements Map<K,Collection<V>>

A Map which allows each to be associated with multiple values.

Since:

1.6 implements Map interface, additional utility methods

Nested Class Summary

Nested classes/interfaces inherited from interface java.util.Map

Map.Entry<K extends Object,V extends Object>

Field Summary

Fields

Modifier and Type	Field	Description
protected boolean	isConcurrent
protected boolean	isReadOptimized
protected Map<K,Collection<V>>	storage

Constructor Summary

Constructors

Constructor	Description
Multimap()	Creates a non-concurrent Multimap.
Multimap(boolean concurrent)
Multimap(boolean concurrent, boolean readOnly)
Multimap(boolean concurrent, boolean readOnly, Map<K,? extends Collection<V>> other)
Multimap(Multimap<K,V> other)	Copy constructor.

Method Summary

Modifier and Type	Method	Description
void	clear()	Removes all mappings.
boolean	containsKey(Object key)
boolean	containsValue(Object value)
Set<Map.Entry<K,Collection<V>>>	entrySet()
boolean	equals(Object obj)
Collection<V>	get(Object key)	Returns all values associated with the key.
Collection<V>	getMutable(Object key)	Returns all values associated with the key.
int	hashCode()
boolean	hasKey(K key)
boolean	isEmpty()
boolean	isThreadSafe()
Set<K>	keySet()
protected Collection<V>	newCollection()	Convenience method for creating new values for entries.
protected Collection<V>	newCollection(Collection<? extends V> values)	Convenience method for creating new values for entries.
protected Map<K,Collection<V>>	newMapDelegate()	Convenience method for creating a new underlying Multimap.
protected Map<K,Collection<V>>	newMapDelegate(Map<? extends K,? extends Collection<V>> initial)	Convenience method for creating a new underlying Multimap.
Collection<V>	put(K key, Collection<V> values)
Collection<V>	put(K key, Collection<V> values, boolean wrap)	Associates the key with the given values, overwriting the entry if the key is present.
boolean	put(K key, V value)	Adds the given value to the associations for the key.
void	putAll(Map<? extends K,? extends Collection<V>> m)
boolean	putAll(K key, Collection<V> values)	Associates all of the specified values for the given key.
boolean	putAll(K key, Collection<V> values, boolean wrap)	Associates all of the specified values for the given key.
protected boolean	putAll(K key, Collection<V> values, boolean create, boolean replace, boolean wrap)	Replaces the entry in this Multimap with the specified values.
boolean	putAllIfPresent(K key, Collection<V> values)	Adds all of the specified values to the collection associated with the key if a mapping for the key exists in this Multimap.
boolean	putIfPresent(Object key, V value)	Associates the value with the key if the key already exists.
Collection<V>	remove(Object key)	Deletes the specified key from this map.
boolean	remove(Object key, Object value)	Removes the specified value associated with the given key.
boolean	removeAll(Object key)	Removes all values associated with the key, leaving the key itself in place, by calling Collection.clear() if the mapping is present.
boolean	removeAll(Object key, Collection<V> values)	Removes all of the specified values associated with the key.
boolean	replaceValues(K key, Collection<V> values)	Replaces the values associated with the key with the values from the specified collection.
int	size()
int	size(K key)	Returns the number of values associated with the key.
Stream<V>	stream(Object key)	Streams the values for the given key.
Stream<V>	streamAll()
String	toString()
Collection<Collection<V>>	values()

Methods inherited from class java.lang.Object

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

Methods inherited from interface java.util.Map

compute, computeIfAbsent, computeIfPresent, forEach, getOrDefault, merge, putIfAbsent, replace, replace, replaceAll

Field Detail

storage

protected final Map<K,Collection<V>> storage

isConcurrent

protected final boolean isConcurrent

isReadOptimized

protected final boolean isReadOptimized

Constructor Detail

Multimap

public Multimap()

Creates a non-concurrent Multimap.

Multimap

public Multimap(boolean concurrent)

Parameters:

concurrent - Whether this implementation should be thread-safe.

Since:

1.6

Multimap

public Multimap(boolean concurrent,
                boolean readOnly)

Parameters:

concurrent - Whether this implementation should be thread-safe.

readOnly - Whether this Multimap (i.e. both the underlying Map itself and collections associated with keys) will be immutable or rarely written to.

Since:

1.6

Multimap

public Multimap(boolean concurrent,
                boolean readOnly,
                Map<K,? extends Collection<V>> other)

Parameters:

concurrent - Whether this implementation should be thread-safe.

readOnly - Whether this Multimap (i.e. both the underlying Map itself and collections associated with keys) will be immutable or rarely written to.

other - The Multimap to copy from.

Since:

1.6

Multimap

public Multimap(Multimap<K,V> other)

Copy constructor.

Parameters:

other - The Multimap to copy from.

Throws:

NullPointerException - If the Multimap is null.

Method Detail

newMapDelegate

protected final Map<K,Collection<V>> newMapDelegate()

Convenience method for creating a new underlying Multimap.

Parameters:

initial - The elements to add to the multimap.

Since:

1.6

See Also:

newMapDelegate(Map)

newMapDelegate

protected Map<K,Collection<V>> newMapDelegate(Map<? extends K,? extends Collection<V>> initial)

Convenience method for creating a new underlying Multimap.

Parameters:

initial - The elements to add to the multimap.

Returns:

A suitable Map based on the thread-safety of this Multimap.

newCollection

protected final Collection<V> newCollection()

Convenience method for creating new values for entries.

Returns:

A suitable collection based on the thread-safety of this Multimap.

Since:

1.6

See Also:

newCollection(Collection)

newCollection

protected Collection<V> newCollection(Collection<? extends V> values)

Convenience method for creating new values for entries.

Parameters:

values - The items to add to the returned collection.

Returns:

A suitable collection based on the thread-safety of this Multimap.

Since:

1.6

get

public Collection<V> get(Object key)

Returns all values associated with the key. The returned collection is immutable.

Specified by:

get in interface Map<K,V>

Parameters:

key -

Returns:

The associated values, or an empty collection if the key was not present.

getMutable

public Collection<V> getMutable(Object key)

Returns all values associated with the key. The returned collection is the collection used internally to associate the key with its values.

Parameters:

key -

Returns:

A collection of the associated values, or null if no mapping was present.

Since:

1.6

put

public boolean put(K key,
                   V value)

Adds the given value to the associations for the key.

Parameters:

key -

value -

Returns:

Whether a mapping existed for the key.

putIfPresent

public boolean putIfPresent(Object key,
                            V value)

Associates the value with the key if the key already exists. Note that this operation will succeed even if the key has no values associated with it; only if the key is present.

Parameters:

key -

value -

Returns:

Whether the key was present and value was added.

Since:

1.6

putAllIfPresent

public boolean putAllIfPresent(K key,
                               Collection<V> values)

Adds all of the specified values to the collection associated with the key if a mapping for the key exists in this Multimap.

Parameters:

key -

values - The additional values to associate with the key.

Returns:

Whether the key was present and the values were added.

Since:

1.6

remove

public boolean remove(Object key,
                      Object value)

Removes the specified value associated with the given key.

Specified by:

remove in interface Map<K,V>

Parameters:

key -

value -

Returns:

Whether the key was present and the associated collection of values was changed.

removeAll

public boolean removeAll(Object key)

Removes all values associated with the key, leaving the key itself in place, by calling Collection.clear() if the mapping is present.

Parameters:

key -

Returns:

Whether the key was present and the collection changed as a result.

Since:

1.6

removeAll

public boolean removeAll(Object key,
                         Collection<V> values)

Removes all of the specified values associated with the key. Note that if the collection contains all values associated with the key, the key itself will not be removed.

Parameters:

key -

values - The values to remove.

Returns:

Whether the key was present and the associated collection of values was changed as a result of this call.

Since:

1.6

remove

public Collection<V> remove(Object key)

Deletes the specified key from this map.

Specified by:

remove in interface Map<K,V>

Parameters:

key -

Returns:

The values associated with the key, or null if no mapping was present.

clear

public void clear()

Removes all mappings.

Specified by:

clear in interface Map<K,V>

containsKey

public boolean containsKey(Object key)

Specified by:

containsKey in interface Map<K,V>

Parameters:

key -

Returns:

Whether the given key has one or more values associated with it.

hasKey

public boolean hasKey(K key)

Parameters:

key -

Returns:

Whether the key is present in they keySet.

Since:

1.6

putAll

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

Associates all of the specified values for the given key. Previously associated values will not be removed.

Parameters:

key -

values - The additional values to associate with the key.

Returns:

Whether the key was present.

Since:

1.6 Values are wrapped into the appropriate collection, and existing values are appended to rather than replaced.

putAll

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

Associates all of the specified values for the given key. Previously associated values will not be removed.

Parameters:

key -

values - The additional values to associate with the key.

wrap - Whether to wrap the provided values into a new collection.

Returns:

Whether the key was present.

Since:

1.6

replaceValues

public boolean replaceValues(K key,
                             Collection<V> values)

Replaces the values associated with the key with the values from the specified collection. The Collection associated with the key itself will not be replaced; only its values will be. Note that unlike putAll, a new entry will not be created if a mapping for the key doesn't exist.

Parameters:

key -

values - The collection of values to copy from.

Returns:

Whether the collection was changed as a result of

Since:

1.6

put

public Collection<V> put(K key,
                         Collection<V> values,
                         boolean wrap)

Associates the key with the given values, overwriting the entry if the key is present. Note that the associated collection will not be the same object as the parameter.

Parameters:

key -

values - The values to copy from.

wrap - Whether to wrap the provided values into a new collection.

Returns:

The previously associated values, or null if no mapping was present.

Since:

1.6

put

public Collection<V> put(K key,
                         Collection<V> values)

Specified by:

put in interface Map<K,V>

putAll

protected boolean putAll(K key,
                         Collection<V> values,
                         boolean create,
                         boolean replace,
                         boolean wrap)

Replaces the entry in this Multimap with the specified values.

Parameters:

key -

values - The values to associate with the key.

create - Creates a new entry with the values if one doesn't exist.

replace - Whether to append or replace existing values.

wrap - Whether to wrap the values into a known data structure.

Returns:

Whether the operation had an effect on this Multimap.

Since:

1.6

isThreadSafe

public boolean isThreadSafe()

Returns:

Since:

1.6

stream

public Stream<V> stream(Object key)

Streams the values for the given key.

Parameters:

key -

Returns:

The stream of values for the key, or an empty stream if the key is not present.

Since:

1.6

streamAll

public Stream<V> streamAll()

Returns:

A flattened Stream of all values in this Multimap.

Since:

1.6

entrySet

public Set<Map.Entry<K,Collection<V>>> entrySet()

Specified by:

entrySet in interface Map<K,V>

Returns:

An immutable KeySetView of this Multimap.

Since:

1.6

size

public int size()

Specified by:

size in interface Map<K,V>

Returns:

The number of keys.

Since:

1.6

size

public int size(K key)

Returns the number of values associated with the key.

Parameters:

key -

Returns:

The number of associated values, or -1 if the key was not present.

Since:

1.6

equals

public boolean equals(Object obj)

Specified by:

equals in interface Map<K,V>

Overrides:

equals in class Object

Since:

1.6

hashCode

public int hashCode()

Specified by:

hashCode in interface Map<K,V>

Overrides:

hashCode in class Object

Since:

1.6

toString

public String toString()

Overrides:

toString in class Object

isEmpty

public boolean isEmpty()

Specified by:

isEmpty in interface Map<K,V>

Since:

1.6

containsValue

public boolean containsValue(Object value)

Specified by:

containsValue in interface Map<K,V>

Since:

1.6

putAll

public void putAll(Map<? extends K,? extends Collection<V>> m)

Specified by:

putAll in interface Map<K,V>

Since:

1.6

keySet

public Set<K> keySet()

Specified by:

keySet in interface Map<K,V>

Since:

1.6

values

public Collection<Collection<V>> values()

Specified by:

values in interface Map<K,V>

Since:

1.6