Package com.globalmentor.collections

Interface ReverseMap<K,V>

Type Parameters:

K - The type of map key.

V - The type of map value.

All Superinterfaces:

Map<K,V>

All Known Subinterfaces:

ReadWriteLockReverseMap<K,V>

All Known Implementing Classes:

DecoratorReadWriteLockReverseMap, DecoratorReverseMap

public interface ReverseMap<K,V>
extends Map<K,V>

A map that also allows lookup of the map keys keyed to the values.

The keys and values in this map have a one-to-one relationship. Associating multiple values with a key will likely result in errant functionality.

Author:

Garret Wilson

Nested Class Summary

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

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

Method Summary

Modifier and Type	Method	Description
K	getKey(V value)	Returns the key that represents the given value.
K	removeValue(V value)	Removes the mapping for a value from this map if it is present.

Methods inherited from interface java.util.Map

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

Method Details

getKey

K getKey(V value)

Returns the key that represents the given value.

Parameters:

value - The value whose associated key is to be returned.

Returns:

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

Throws:

ClassCastException - Thrown if the value is of an inappropriate type for this map (optional).

NullPointerException - Thrown if the value is null and this map does not not permit null values (optional).

See Also:

• Map.containsValue(Object)

removeValue

K removeValue(V value)

Removes the mapping for a value from this map if it is present.

Parameters:

value - The value whose mapping is to be removed from the map.

Returns:

The previous key associated with the value, or null if there was no mapping for the value.

Throws:

UnsupportedOperationException - if the remove operation is not supported by this map

ClassCastException - if the value is of an inappropriate type for this map (optional).

NullPointerException - if the specified value is null and this map does not permit null values (optional).