net.cscott.jutil
public class GenericMultiMap<K,V> extends Object implements MultiMap<K,V>
GenericMultiMap is a default implementation of a
MultiMap.
FSK: right now the implementation tries to preserve the property that if a key 'k' maps to an empty collection 'c' in some MultiMap 'mm', then users of 'mm' will not be able to see that 'k' is a member of the keySet for 'mm'. However, it does not preserve this property when mm.getValues(k) is used as a means to operate on the state of 'mm', and it is not clear to me whether one can even ensure that the property can be maintained if arbitrary operations on mm.getValues(k) are passed on to 'mm'.
Version: $Id: GenericMultiMap.java,v 1.3 2004/01/13 21:40:19 cananian Exp $
| Constructor Summary | |
|---|---|
| GenericMultiMap() Creates a MultiMap using a HashMap for
the map and HashSets for the value collections.
| |
| GenericMultiMap(CollectionFactory<V> cf) Creates a MultiMap using a HashMap for
the map and the specified CollectionFactory to
create the value collections. | |
| GenericMultiMap(MapFactory<K,Collection<V>> mf, CollectionFactory<V> cf) Creates a MultiMap using the specified
MapFactory to create the map and the specified
CollectionFactory to create the value collections. | |
| Method Summary | |
|---|---|
| boolean | add(K key, V value) Ensures that this contains an association from
key to value.
|
| boolean | addAll(K key, Collection<? extends V> values) Adds to the current mappings: associations for
key to each value in values.
|
| boolean | addAll(MultiMap<? extends K,? extends V> mm) Add all mappings in the given multimap to this multimap. |
| void | clear() |
| boolean | contains(Object a, Object b) Returns true if a has a mapping to b
in this.
|
| boolean | containsKey(Object key) |
| boolean | containsValue(Object value) |
| MultiMapSet<K,V> | entrySet() Returns a set view of the mappings contained in this map.
|
| boolean | equals(Object o) |
| V | get(Object key) Returns some arbitrary value from the set of values to which
this map maps the specified key. |
| Collection<V> | getValues(K key) Returns the collection of Values associated with
key. |
| int | hashCode() |
| boolean | isEmpty() |
| Set<K> | keySet() Returns a set view of the keys in this map. |
| V | put(K key, V value) Associates the specified value with the specified key in this
map. |
| void | putAll(Map<? extends K,? extends V> t) Copies the mappings from the specified map to this
map. |
| V | remove(Object key) Removes all mappings for this key from this map if present.
|
| boolean | remove(Object key, Object value) Removes a mapping from key to value from this map if present.
|
| boolean | removeAll(K key, Collection<?> values) Removes from the current mappings: associations for
key to any value in values.
|
| boolean | retainAll(K key, Collection<?> values) Removes from the current mappings: associations for
key to any value not in values.
|
| int | size() |
| String | toString() |
| Collection<V> | values() Returns a collection view of the values contained in this
map. |
MultiMap using a HashMap for
the map and HashSets for the value collections.
To gain more control over the specific sets/map used in
internal representation of this, use the more
specific constructor
that takes CollectionFactorys.MultiMap using a HashMap for
the map and the specified CollectionFactory to
create the value collections.MultiMap using the specified
MapFactory to create the map and the specified
CollectionFactory to create the value collections.this contains an association from
key to value.
(MultiMap specific operation).Returns: true if this mapping changed as a result of
the call
key to each value in values.
(MultiMap specific operation).Returns: true if this mapping changed as a result
of the call
a has a mapping to b
in this.
(MultiMap specific operation).Map.Entrys. The returned set is actually a
MultiMapSet, from which you can get back the
original MultiMap.null if
the map contains no mapping for the key; it's also possible
that the map explicitly maps the key to null.
The containsKey operation may be used to
distinquish these two cases.
Note that if only the put method is used to
modify this, then get will operate
just as it would in any other Map.key. Modifications to the returned
Collection affect this as well. If
there are no Values currently associated with
key, constructs a new, mutable, empty
Collection and returns it.
(MultiMap specific operation).null if no values were associated previously.putAll(mm) where mm is a
MultiMap will NOT add all of the mappings in
mm; it will only add all of the Keys in
mm, mapping each Key to one of the Values it
mapped to in mm. To add all of the mappings from
another MultiMap, use
addAll(MultiMap).null if there was no mapping for key.this was modified as a result of
this operation, else returns false.key to any value in values.
(MultiMap specific operation).Returns: true if this mapping changed as a result
of the call
key to any value not in values.
(MultiMap specific operation).Returns: true if this mapping changed as a result
of the call