aima.core.util.datastructure

Class TwoKeyHashMap<K1,K2,V>

java.lang.Object

java.util.AbstractMap<K,V>

java.util.HashMap<Pair<K1,K2>,V>

aima.core.util.datastructure.TwoKeyHashMap<K1,K2,V>

Type Parameters:

K1 - First key

K2 - Second key

V - Result value

All Implemented Interfaces:

java.io.Serializable, java.lang.Cloneable, java.util.Map<Pair<K1,K2>,V>

public class TwoKeyHashMap<K1,K2,V>
extends java.util.HashMap<Pair<K1,K2>,V>

Provides a hash map which is indexed by two keys. In fact this is just a hash map which is indexed by a pair containing the two keys. The provided two-key access methods try to increase code readability.

Author:

Ruediger Lunde, Mike Stampone

See Also:

Serialized Form

Nested Class Summary

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

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

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

java.util.Map.Entry<K,V>

Constructor Summary

Constructors

Constructor and Description
TwoKeyHashMap()

Method Summary

Modifier and Type	Method and Description
boolean	containsKey(K1 key1, K2 key2) Returns true if this map contains a mapping for the specified key pair.
V	get(K1 key1, K2 key2) Returns the value to which the specified key pair is mapped in this two key hash map, or null if the map contains no mapping for this key pair.
void	put(K1 key1, K2 key2, V value) Associates the specified value with the specified key pair in this map.
V	removeKey(K1 key1, K2 key2) Removes the mapping for this key pair from this map if present.

Methods inherited from class java.util.HashMap

clear, clone, compute, computeIfAbsent, computeIfPresent, containsKey, containsValue, entrySet, forEach, get, getOrDefault, isEmpty, keySet, merge, put, putAll, putIfAbsent, remove, remove, replace, replace, replaceAll, size, values

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

TwoKeyHashMap

public TwoKeyHashMap()

Method Detail

put

public void put(K1 key1,
                K2 key2,
                V value)

Associates the specified value with the specified key pair in this map. If the map previously contained a mapping for this key pair, the old value is replaced.

Parameters:

key1 - the first key of the key pair, with which the specified value is to be associated.

key2 - the second key of the key pair, with which the specified value is to be associated.

value - the value to be associated with the key pair.

get

public V get(K1 key1,
             K2 key2)

Returns the value to which the specified key pair is mapped in this two key hash map, or null if the map contains no mapping for this key pair. A return value of null does not necessarily indicate that the map contains no mapping for the key; it is also possible that the map explicitly maps the key to null. The containsKey method may be used to distinguish these two cases.

Parameters:

key1 - the first key of the key pair, whose associated value is to be returned.

key2 - the second key of the key pair, whose associated value is to be returned.

Returns:

the value to which this map maps the specified key pair, or null if the map contains no mapping for this key pair.

containsKey

public boolean containsKey(K1 key1,
                           K2 key2)

Returns true if this map contains a mapping for the specified key pair.

Parameters:

key1 - the first key of the key pair whose presence in this map is to be tested.

key2 - the second key of the key pair whose presence in this map is to be tested.

Returns:

true if this map contains a mapping for the specified key.

removeKey

public V removeKey(K1 key1,
                   K2 key2)

Removes the mapping for this key pair from this map if present.

Parameters:

key1 - the first key of the key pair, whose mapping is to be removed from the map.

key2 - the second key of the key pair, whose mapping is to be removed from the map.

Returns:

the previous value associated with the specified key pair, or null if there was no mapping for the key pair. A null return can also indicate that the map previously associated null with the specified key pair.