Skip to content

Most visited

Recently visited

navigation
Added in API level 1

EnumMap

public class EnumMap
extends AbstractMap<K extends Enum<K>, V> implements Serializable, Cloneable, Map<K extends Enum<K>, V>

java.lang.Object
   ↳ java.util.AbstractMap<K extends java.lang.Enum<K>, V>
     ↳ java.util.EnumMap<K extends java.lang.Enum<K>, V>


An Map specialized for use with Enum types as keys.

Summary

Public constructors

EnumMap(Class<K> keyType)

Constructs an empty EnumMap using the given key type.

EnumMap(EnumMap<K, ? extends V> map)

Constructs an EnumMap using the same key type as the given EnumMap and initially containing the same mappings.

EnumMap(Map<K, ? extends V> map)

Constructs an EnumMap initialized from the given map.

Public methods

void clear()

Removes all elements from this EnumMap, leaving it empty.

EnumMap<K, V> clone()

Returns a shallow copy of this EnumMap.

boolean containsKey(Object key)

Returns whether this EnumMap contains the specified key.

boolean containsValue(Object value)

Returns whether this EnumMap contains the specified value.

Set<Entry<K, V>> entrySet()

Returns a Set containing all of the mappings in this EnumMap.

boolean equals(Object object)

Compares the argument to the receiver, and returns true if the specified Object is an EnumMap and both EnumMaps contain the same mappings.

V get(Object key)

Returns the value of the mapping with the specified key.

Set<K> keySet()

Returns a set of the keys contained in this EnumMap.

V put(K key, V value)

Maps the specified key to the specified value.

void putAll(Map<? extends K, ? extends V> map)

Copies every mapping in the specified Map to this EnumMap.

V remove(Object key)

Removes a mapping with the specified key from this EnumMap.

int size()

Returns the number of elements in this EnumMap.

Collection<V> values()

Returns a Collection of the values contained in this EnumMap.

Inherited methods

From class java.util.AbstractMap
From class java.lang.Object
From interface java.util.Map
From interface java.util.Map

Public constructors

EnumMap

Added in API level 1
EnumMap (Class<K> keyType)

Constructs an empty EnumMap using the given key type.

Parameters
keyType Class: the class object giving the type of the keys used by this EnumMap.
Throws
NullPointerException if keyType is null.

EnumMap

Added in API level 1
EnumMap (EnumMap<K, ? extends V> map)

Constructs an EnumMap using the same key type as the given EnumMap and initially containing the same mappings.

Parameters
map EnumMap: the EnumMap from which this EnumMap is initialized.
Throws
NullPointerException if map is null.

EnumMap

Added in API level 1
EnumMap (Map<K, ? extends V> map)

Constructs an EnumMap initialized from the given map. If the given map is an EnumMap instance, this constructor behaves in the exactly the same way as EnumMap(EnumMap)}. Otherwise, the given map should contain at least one mapping.

Parameters
map Map: the map from which this EnumMap is initialized.
Throws
IllegalArgumentException if map is not an EnumMap instance and does not contain any mappings.
NullPointerException if map is null.

Public methods

clear

Added in API level 1
void clear ()

Removes all elements from this EnumMap, leaving it empty.

See also:

clone

Added in API level 1
EnumMap<K, V> clone ()

Returns a shallow copy of this EnumMap.

Returns
EnumMap<K, V> a shallow copy of this EnumMap.

containsKey

Added in API level 1
boolean containsKey (Object key)

Returns whether this EnumMap contains the specified key.

Parameters
key Object: the key to search for.
Returns
boolean true if this EnumMap contains the specified key, false otherwise.

containsValue

Added in API level 1
boolean containsValue (Object value)

Returns whether this EnumMap contains the specified value.

Parameters
value Object: the value to search for.
Returns
boolean true if this EnumMap contains the specified value, false otherwise.

entrySet

Added in API level 1
Set<Entry<K, V>> entrySet ()

Returns a Set containing all of the mappings in this EnumMap. Each mapping is an instance of Map.Entry. As the Set is backed by this EnumMap, changes in one will be reflected in the other.

The order of the entries in the set will be the order that the enum keys were declared in.

Returns
Set<Entry<K, V>> a Set of the mappings.

equals

Added in API level 1
boolean equals (Object object)

Compares the argument to the receiver, and returns true if the specified Object is an EnumMap and both EnumMaps contain the same mappings.

Parameters
object Object: the Object to compare with this EnumMap.
Returns
boolean boolean true if object is the same as this EnumMap, false otherwise.

See also:

get

Added in API level 1
V get (Object key)

Returns the value of the mapping with the specified key.

Parameters
key Object: the key.
Returns
V the value of the mapping with the specified key, or null if no mapping for the specified key is found.

keySet

Added in API level 1
Set<K> keySet ()

Returns a set of the keys contained in this EnumMap. The Set is backed by this EnumMap so changes to one are reflected in the other. The Set does not support adding.

The order of the set will be the order that the enum keys were declared in.

Returns
Set<K> a Set of the keys.

put

Added in API level 1
V put (K key, 
                V value)

Maps the specified key to the specified value.

Parameters
key K: the key.
value V: the value.
Returns
V the value of any previous mapping with the specified key or null if there was no mapping.
Throws
UnsupportedOperationException if adding to this map is not supported.
ClassCastException if the class of the key or value is inappropriate for this map.
IllegalArgumentException if the key or value cannot be added to this map.
NullPointerException if the key or value is null and this EnumMap does not support null keys or values.

putAll

Added in API level 1
void putAll (Map<? extends K, ? extends V> map)

Copies every mapping in the specified Map to this EnumMap.

Parameters
map Map: the Map to copy mappings from.
Throws
UnsupportedOperationException if adding to this EnumMap is not supported.
ClassCastException if the class of a key or value is inappropriate for this EnumMap.
IllegalArgumentException if a key or value cannot be added to this map.
NullPointerException if a key or value is null and this EnumMap does not support null keys or values.

remove

Added in API level 1
V remove (Object key)

Removes a mapping with the specified key from this EnumMap.

Parameters
key Object: the key of the mapping to remove.
Returns
V the value of the removed mapping or null if no mapping for the specified key was found.
Throws
UnsupportedOperationException if removing from this EnumMap is not supported.

size

Added in API level 1
int size ()

Returns the number of elements in this EnumMap.

Returns
int the number of elements in this EnumMap.

values

Added in API level 1
Collection<V> values ()

Returns a Collection of the values contained in this EnumMap. The returned Collection complies with the general rule specified in values(). The Collection's Iterator will return the values in the their corresponding keys' natural order (the Enum constants are declared in this order).

The order of the values in the collection will be the order that their corresponding enum keys were declared in.

Returns
Collection<V> a collection of the values contained in this EnumMap.
This site uses cookies to store your preferences for site-specific language and display options.

Hooray!

This class requires API level or higher

This doc is hidden because your selected API level for the documentation is . You can change the documentation API level with the selector above the left navigation.

For more information about specifying the API level your app requires, read Supporting Different Platform Versions.