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java.lang.Objectorg.apache.commons.collections4.map.AbstractIterableMap<K,V>
org.apache.commons.collections4.map.AbstractMapDecorator<MultiKey<? extends K>,V>
org.apache.commons.collections4.map.MultiKeyMap<K,V>
public class MultiKeyMap<K,V>
A Map
implementation that uses multiple keys to map the value.
This class is the most efficient way to uses multiple keys to map to a value.
The best way to use this class is via the additional map-style methods.
These provide get
, containsKey
, put
and
remove
for individual keys which operate without extra object creation.
The additional methods are the main interface of this map.
As such, you will not normally hold this map in a variable of type Map
.
The normal map methods take in and return a MultiKey
.
If you try to use put()
with any other object type a
ClassCastException
is thrown. If you try to use null
as
the key in put()
a NullPointerException
is thrown.
This map is implemented as a decorator of a AbstractHashedMap
which
enables extra behaviour to be added easily.
MultiKeyMap.decorate(new LinkedMap())
creates an ordered map.
MultiKeyMap.decorate(new LRUMap())
creates an least recently used map.
MultiKeyMap.decorate(new ReferenceMap())
creates a garbage collector sensitive map.
IdentityMap
and ReferenceIdentityMap
are unsuitable
for use as the key comparison would work on the whole MultiKey, not the elements within.
As an example, consider a least recently used cache that uses a String airline code and a Locale to lookup the airline's name:
private MultiKeyMap cache = MultiKeyMap.multiKeyMap(new LRUMap(50)); public String getAirlineName(String code, String locale) { String name = (String) cache.get(code, locale); if (name == null) { name = getAirlineNameFromDB(code, locale); cache.put(code, locale, name); } return name; }
Note that MultiKeyMap is not synchronized and is not thread-safe. If you wish to use this map from multiple threads concurrently, you must use appropriate synchronization. This class may throw exceptions when accessed by concurrent threads without synchronization.
Nested Class Summary |
---|
Nested classes/interfaces inherited from interface java.util.Map |
---|
Map.Entry<K,V> |
Constructor Summary | |
---|---|
|
MultiKeyMap()
Constructs a new MultiKeyMap that decorates a HashedMap . |
protected |
MultiKeyMap(AbstractHashedMap<MultiKey<? extends K>,V> map)
Constructor that decorates the specified map and is called from multiKeyMap(AbstractHashedMap) . |
Method Summary | ||
---|---|---|
protected void |
checkKey(MultiKey<?> key)
Check to ensure that input keys are valid MultiKey objects. |
|
MultiKeyMap<K,V> |
clone()
Clones the map without cloning the keys or values. |
|
boolean |
containsKey(Object key1,
Object key2)
Checks whether the map contains the specified multi-key. |
|
boolean |
containsKey(Object key1,
Object key2,
Object key3)
Checks whether the map contains the specified multi-key. |
|
boolean |
containsKey(Object key1,
Object key2,
Object key3,
Object key4)
Checks whether the map contains the specified multi-key. |
|
boolean |
containsKey(Object key1,
Object key2,
Object key3,
Object key4,
Object key5)
Checks whether the map contains the specified multi-key. |
|
protected AbstractHashedMap<MultiKey<? extends K>,V> |
decorated()
Gets the map being decorated. |
|
V |
get(Object key1,
Object key2)
Gets the value mapped to the specified multi-key. |
|
V |
get(Object key1,
Object key2,
Object key3)
Gets the value mapped to the specified multi-key. |
|
V |
get(Object key1,
Object key2,
Object key3,
Object key4)
Gets the value mapped to the specified multi-key. |
|
V |
get(Object key1,
Object key2,
Object key3,
Object key4,
Object key5)
Gets the value mapped to the specified multi-key. |
|
protected int |
hash(Object key1,
Object key2)
Gets the hash code for the specified multi-key. |
|
protected int |
hash(Object key1,
Object key2,
Object key3)
Gets the hash code for the specified multi-key. |
|
protected int |
hash(Object key1,
Object key2,
Object key3,
Object key4)
Gets the hash code for the specified multi-key. |
|
protected int |
hash(Object key1,
Object key2,
Object key3,
Object key4,
Object key5)
Gets the hash code for the specified multi-key. |
|
protected boolean |
isEqualKey(AbstractHashedMap.HashEntry<MultiKey<? extends K>,V> entry,
Object key1,
Object key2)
Is the key equal to the combined key. |
|
protected boolean |
isEqualKey(AbstractHashedMap.HashEntry<MultiKey<? extends K>,V> entry,
Object key1,
Object key2,
Object key3)
Is the key equal to the combined key. |
|
protected boolean |
isEqualKey(AbstractHashedMap.HashEntry<MultiKey<? extends K>,V> entry,
Object key1,
Object key2,
Object key3,
Object key4)
Is the key equal to the combined key. |
|
protected boolean |
isEqualKey(AbstractHashedMap.HashEntry<MultiKey<? extends K>,V> entry,
Object key1,
Object key2,
Object key3,
Object key4,
Object key5)
Is the key equal to the combined key. |
|
MapIterator<MultiKey<? extends K>,V> |
mapIterator()
Obtains a MapIterator over the map. |
|
static
|
multiKeyMap(AbstractHashedMap<MultiKey<? extends K>,V> map)
Decorates the specified map to add the MultiKeyMap API and fast query. |
|
V |
put(K key1,
K key2,
K key3,
K key4,
K key5,
V value)
Stores the value against the specified multi-key. |
|
V |
put(K key1,
K key2,
K key3,
K key4,
V value)
Stores the value against the specified multi-key. |
|
V |
put(K key1,
K key2,
K key3,
V value)
Stores the value against the specified multi-key. |
|
V |
put(K key1,
K key2,
V value)
Stores the value against the specified multi-key. |
|
V |
put(MultiKey<? extends K> key,
V value)
Puts the key and value into the map, where the key must be a non-null MultiKey object. |
|
void |
putAll(Map<? extends MultiKey<? extends K>,? extends V> mapToCopy)
Copies all of the keys and values from the specified map to this map. |
|
V |
remove(Object key1,
Object key2)
Removes the specified multi-key from this map. |
|
V |
remove(Object key1,
Object key2,
Object key3)
Removes the specified multi-key from this map. |
|
V |
remove(Object key1,
Object key2,
Object key3,
Object key4)
Removes the specified multi-key from this map. |
|
V |
remove(Object key1,
Object key2,
Object key3,
Object key4,
Object key5)
Removes the specified multi-key from this map. |
|
boolean |
removeAll(Object key1)
Removes all mappings where the first key is that specified. |
|
boolean |
removeAll(Object key1,
Object key2)
Removes all mappings where the first two keys are those specified. |
|
boolean |
removeAll(Object key1,
Object key2,
Object key3)
Removes all mappings where the first three keys are those specified. |
|
boolean |
removeAll(Object key1,
Object key2,
Object key3,
Object key4)
Removes all mappings where the first four keys are those specified. |
Methods inherited from class org.apache.commons.collections4.map.AbstractMapDecorator |
---|
clear, containsKey, containsValue, entrySet, equals, get, hashCode, isEmpty, keySet, remove, size, toString, values |
Methods inherited from class java.lang.Object |
---|
finalize, getClass, notify, notifyAll, wait, wait, wait |
Methods inherited from interface java.util.Map |
---|
clear, containsKey, containsValue, entrySet, equals, get, hashCode, isEmpty, keySet, remove, size, values |
Methods inherited from interface org.apache.commons.collections4.Put |
---|
clear |
Methods inherited from interface org.apache.commons.collections4.Get |
---|
containsKey, containsValue, entrySet, get, isEmpty, keySet, remove, size, values |
Constructor Detail |
---|
public MultiKeyMap()
HashedMap
.
protected MultiKeyMap(AbstractHashedMap<MultiKey<? extends K>,V> map)
multiKeyMap(AbstractHashedMap)
.
The map must not be null and should be empty or only contain valid keys.
This constructor performs no validation.
map
- the map to decorateMethod Detail |
---|
public static <K,V> MultiKeyMap<K,V> multiKeyMap(AbstractHashedMap<MultiKey<? extends K>,V> map)
K
- the key typeV
- the value typemap
- the map to decorate, not null
IllegalArgumentException
- if the map is null or not emptypublic V get(Object key1, Object key2)
key1
- the first keykey2
- the second key
public boolean containsKey(Object key1, Object key2)
key1
- the first keykey2
- the second key
public V put(K key1, K key2, V value)
key1
- the first keykey2
- the second keyvalue
- the value to store
public V remove(Object key1, Object key2)
key1
- the first keykey2
- the second key
protected int hash(Object key1, Object key2)
key1
- the first keykey2
- the second key
protected boolean isEqualKey(AbstractHashedMap.HashEntry<MultiKey<? extends K>,V> entry, Object key1, Object key2)
entry
- the entry to compare tokey1
- the first keykey2
- the second key
public V get(Object key1, Object key2, Object key3)
key1
- the first keykey2
- the second keykey3
- the third key
public boolean containsKey(Object key1, Object key2, Object key3)
key1
- the first keykey2
- the second keykey3
- the third key
public V put(K key1, K key2, K key3, V value)
key1
- the first keykey2
- the second keykey3
- the third keyvalue
- the value to store
public V remove(Object key1, Object key2, Object key3)
key1
- the first keykey2
- the second keykey3
- the third key
protected int hash(Object key1, Object key2, Object key3)
key1
- the first keykey2
- the second keykey3
- the third key
protected boolean isEqualKey(AbstractHashedMap.HashEntry<MultiKey<? extends K>,V> entry, Object key1, Object key2, Object key3)
entry
- the entry to compare tokey1
- the first keykey2
- the second keykey3
- the third key
public V get(Object key1, Object key2, Object key3, Object key4)
key1
- the first keykey2
- the second keykey3
- the third keykey4
- the fourth key
public boolean containsKey(Object key1, Object key2, Object key3, Object key4)
key1
- the first keykey2
- the second keykey3
- the third keykey4
- the fourth key
public V put(K key1, K key2, K key3, K key4, V value)
key1
- the first keykey2
- the second keykey3
- the third keykey4
- the fourth keyvalue
- the value to store
public V remove(Object key1, Object key2, Object key3, Object key4)
key1
- the first keykey2
- the second keykey3
- the third keykey4
- the fourth key
protected int hash(Object key1, Object key2, Object key3, Object key4)
key1
- the first keykey2
- the second keykey3
- the third keykey4
- the fourth key
protected boolean isEqualKey(AbstractHashedMap.HashEntry<MultiKey<? extends K>,V> entry, Object key1, Object key2, Object key3, Object key4)
entry
- the entry to compare tokey1
- the first keykey2
- the second keykey3
- the third keykey4
- the fourth key
public V get(Object key1, Object key2, Object key3, Object key4, Object key5)
key1
- the first keykey2
- the second keykey3
- the third keykey4
- the fourth keykey5
- the fifth key
public boolean containsKey(Object key1, Object key2, Object key3, Object key4, Object key5)
key1
- the first keykey2
- the second keykey3
- the third keykey4
- the fourth keykey5
- the fifth key
public V put(K key1, K key2, K key3, K key4, K key5, V value)
key1
- the first keykey2
- the second keykey3
- the third keykey4
- the fourth keykey5
- the fifth keyvalue
- the value to store
public V remove(Object key1, Object key2, Object key3, Object key4, Object key5)
key1
- the first keykey2
- the second keykey3
- the third keykey4
- the fourth keykey5
- the fifth key
protected int hash(Object key1, Object key2, Object key3, Object key4, Object key5)
key1
- the first keykey2
- the second keykey3
- the third keykey4
- the fourth keykey5
- the fifth key
protected boolean isEqualKey(AbstractHashedMap.HashEntry<MultiKey<? extends K>,V> entry, Object key1, Object key2, Object key3, Object key4, Object key5)
entry
- the entry to compare tokey1
- the first keykey2
- the second keykey3
- the third keykey4
- the fourth keykey5
- the fifth key
public boolean removeAll(Object key1)
This method removes all the mappings where the MultiKey
has one or more keys, and the first matches that specified.
key1
- the first key
public boolean removeAll(Object key1, Object key2)
This method removes all the mappings where the MultiKey
has two or more keys, and the first two match those specified.
key1
- the first keykey2
- the second key
public boolean removeAll(Object key1, Object key2, Object key3)
This method removes all the mappings where the MultiKey
has three or more keys, and the first three match those specified.
key1
- the first keykey2
- the second keykey3
- the third key
public boolean removeAll(Object key1, Object key2, Object key3, Object key4)
This method removes all the mappings where the MultiKey
has four or more keys, and the first four match those specified.
key1
- the first keykey2
- the second keykey3
- the third keykey4
- the fourth key
protected void checkKey(MultiKey<?> key)
key
- the key to checkpublic MultiKeyMap<K,V> clone()
clone
in class Object
public V put(MultiKey<? extends K> key, V value)
put
in interface Map<MultiKey<? extends K>,V>
put
in interface Put<MultiKey<? extends K>,V>
put
in class AbstractMapDecorator<MultiKey<? extends K>,V>
key
- the non-null MultiKey objectvalue
- the value to store
NullPointerException
- if the key is null
ClassCastException
- if the key is not a MultiKeyMap.put(Object, Object)
public void putAll(Map<? extends MultiKey<? extends K>,? extends V> mapToCopy)
putAll
in interface Map<MultiKey<? extends K>,V>
putAll
in interface Put<MultiKey<? extends K>,V>
putAll
in class AbstractMapDecorator<MultiKey<? extends K>,V>
mapToCopy
- to this map
NullPointerException
- if the mapToCopy or any key within is null
ClassCastException
- if any key in mapToCopy is not a MultiKeyMap.putAll(Map)
public MapIterator<MultiKey<? extends K>,V> mapIterator()
AbstractIterableMap
MapIterator
over the map.
A map iterator is an efficient way of iterating over maps. There is no need to access the entry set or use Map Entry objects.
IterableMapmap = new HashedMap (); MapIterator it = map.mapIterator(); while (it.hasNext()) { String key = it.next(); Integer value = it.getValue(); it.setValue(value + 1); }
mapIterator
in interface IterableGet<MultiKey<? extends K>,V>
mapIterator
in class AbstractIterableMap<MultiKey<? extends K>,V>
protected AbstractHashedMap<MultiKey<? extends K>,V> decorated()
decorated
in class AbstractMapDecorator<MultiKey<? extends K>,V>
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