org.apache.commons.collections4.map

## Class HashedMap<K,V>

- java.lang.Object
- - java.util.AbstractMap<K,V>
  - - org.apache.commons.collections4.map.AbstractHashedMap<K,V>
    - - org.apache.commons.collections4.map.HashedMap<K,V>

- All Implemented Interfaces:
    Serializable, Cloneable, Map<K,V>, Get<K,V>, IterableGet<K,V>, IterableMap<K,V>, Put<K,V>

      public class HashedMap<K,V>
      extends AbstractHashedMap<K,V>
      implements Serializable, Cloneable

  A `Map` implementation that is a general purpose alternative to `HashMap`.

  This implementation improves on the JDK1.4 HashMap by adding the `MapIterator` functionality and many methods for subclassing.

  Note that HashedMap is not synchronized and is not thread-safe. If you wish to use this map from multiple threads concurrently, you must use appropriate synchronization. The simplest approach is to wrap this map using `Collections.synchronizedMap(Map)`. This class may throw exceptions when accessed by concurrent threads without synchronization.

  Since:
    3.0
  Version:
    $Id: HashedMap.java 1533984 2013-10-20 21:12:51Z tn $
  See Also:
    Serialized Form

- - ### Nested Class Summary

    - ### Nested classes/interfaces inherited from class org.apache.commons.collections4.map.AbstractHashedMap

      `AbstractHashedMap.EntrySet<K,V>, AbstractHashedMap.EntrySetIterator<K,V>, AbstractHashedMap.HashEntry<K,V>, AbstractHashedMap.HashIterator<K,V>, AbstractHashedMap.HashMapIterator<K,V>, AbstractHashedMap.KeySet<K>, AbstractHashedMap.KeySetIterator<K>, AbstractHashedMap.Values<V>, AbstractHashedMap.ValuesIterator<V>`

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

      `AbstractMap.SimpleEntry<K,V>, AbstractMap.SimpleImmutableEntry<K,V>`

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

      `Map.Entry<K,V>`

  - ### Field Summary

    - ### Fields inherited from class org.apache.commons.collections4.map.AbstractHashedMap

      `DEFAULT_CAPACITY, DEFAULT_LOAD_FACTOR, DEFAULT_THRESHOLD, GETKEY_INVALID, GETVALUE_INVALID, MAXIMUM_CAPACITY, NO_NEXT_ENTRY, NO_PREVIOUS_ENTRY, NULL, REMOVE_INVALID, SETVALUE_INVALID`

  - ### Constructor Summary

    Constructors
    Constructor and Description
    `HashedMap()` Constructs a new empty map with default size and load factor.
    `HashedMap(int initialCapacity)` Constructs a new, empty map with the specified initial capacity.
    `HashedMap(int initialCapacity, float loadFactor)` Constructs a new, empty map with the specified initial capacity and load factor.
    `HashedMap(Map<? extends K,? extends V> map)` Constructor copying elements from another map.

  - ### Method Summary

    Methods
    Modifier and Type | Method and Description
    --- | ---
    `HashedMap<K,V>` | `clone()` Clones the map without cloning the keys or values.

    - ### Methods inherited from class org.apache.commons.collections4.map.AbstractHashedMap

      `addEntry, addMapping, calculateNewCapacity, calculateThreshold, checkCapacity, clear, containsKey, containsValue, convertKey, createEntry, createEntrySetIterator, createKeySetIterator, createValuesIterator, destroyEntry, doReadObject, doWriteObject, ensureCapacity, entryHashCode, entryKey, entryNext, entrySet, entryValue, equals, get, getEntry, hash, hashCode, hashIndex, init, isEmpty, isEqualKey, isEqualValue, keySet, mapIterator, put, putAll, remove, removeEntry, removeMapping, reuseEntry, size, toString, updateEntry, values`

    - ### Methods inherited from class java.lang.Object

      `finalize, getClass, notify, notifyAll, wait, wait, wait`

- - ### Constructor Detail

    - #### HashedMap

          public HashedMap()

      Constructs a new empty map with default size and load factor.

    - #### HashedMap

          public HashedMap(int initialCapacity)

      Constructs a new, empty map with the specified initial capacity.
      Parameters:
        `initialCapacity` - the initial capacity
      Throws:
        `IllegalArgumentException` - if the initial capacity is negative

    - #### HashedMap

          public HashedMap(int initialCapacity,
                   float loadFactor)

      Constructs a new, empty map with the specified initial capacity and load factor.
      Parameters:
        `initialCapacity` - the initial capacity
        `loadFactor` - the load factor
      Throws:
        `IllegalArgumentException` - if the initial capacity is negative
        `IllegalArgumentException` - if the load factor is less than zero

    - #### HashedMap

          public HashedMap(Map<? extends K,? extends V> map)

      Constructor copying elements from another map.
      Parameters:
        `map` - the map to copy
      Throws:
        `NullPointerException` - if the map is null

  - ### Method Detail

    - #### clone

          public HashedMap<K,V> clone()

      Clones the map without cloning the keys or values.
      Overrides:
        `clone` in class `AbstractHashedMap<K,V>`
      Returns:
        a shallow clone

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