EnumMap Class

Definition

[Android.Runtime.Register("java/util/EnumMap", DoNotGenerateAcw=true)]
[Java.Interop.JavaTypeParameters(new System.String[] { "K extends java.lang.Enum<K>", "V" })]
public class EnumMap : Java.Util.AbstractMap, IDisposable, Java.Interop.IJavaPeerable, Java.IO.ISerializable, Java.Lang.ICloneable

[<Android.Runtime.Register("java/util/EnumMap", DoNotGenerateAcw=true)>]
[<Java.Interop.JavaTypeParameters(new System.String[] { "K extends java.lang.Enum<K>", "V" })>]
type EnumMap = class
    inherit AbstractMap
    interface ISerializable
    interface IJavaObject
    interface IDisposable
    interface IJavaPeerable
    interface ICloneable
    interface IMap

Inheritance

Object

Object

AbstractMap

EnumMap

Attributes

RegisterAttribute JavaTypeParametersAttribute

Implements

IJavaObject IJavaPeerable ISerializable ICloneable IMap IDisposable

Remarks

A specialized Map implementation for use with enum type keys. All of the keys in an enum map must come from a single enum type that is specified, explicitly or implicitly, when the map is created. Enum maps are represented internally as arrays. This representation is extremely compact and efficient.

Enum maps are maintained in the natural order of their keys (the order in which the enum constants are declared). This is reflected in the iterators returned by the collections views (#keySet(), #entrySet(), and #values()).

Iterators returned by the collection views are weakly consistent: they will never throw ConcurrentModificationException and they may or may not show the effects of any modifications to the map that occur while the iteration is in progress.

Null keys are not permitted. Attempts to insert a null key will throw NullPointerException. Attempts to test for the presence of a null key or to remove one will, however, function properly. Null values are permitted.

Like most collection implementations EnumMap is not synchronized. If multiple threads access an enum map concurrently, and at least one of the threads modifies the map, it should be synchronized externally. This is typically accomplished by synchronizing on some object that naturally encapsulates the enum map. If no such object exists, the map should be "wrapped" using the Collections#synchronizedMap method. This is best done at creation time, to prevent accidental unsynchronized access:

Map<EnumKey, V> m
                    = Collections.synchronizedMap(new EnumMap<EnumKey, V>(...));

Implementation note: All basic operations execute in constant time. They are likely (though not guaranteed) to be faster than their HashMap counterparts.

This class is a member of the Java Collections Framework.

Added in 1.5.

Java documentation for java.util.EnumMap.

Portions of this page are modifications based on work created and shared by the Android Open Source Project and used according to terms described in the Creative Commons 2.5 Attribution License.

Constructors

Properties

Methods

Explicit Interface Implementations

Extension Methods

Applies to