HashedMap (Commons Collections 3.2.2 API)

java.lang.Object
- java.util.AbstractMap
- - org.apache.commons.collections.map.AbstractHashedMap
  - - org.apache.commons.collections.map.HashedMap

All Implemented Interfaces:

Serializable, Cloneable, Map, IterableMap
```
public class HashedMap
extends AbstractHashedMap
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:

Commons Collections 3.0

Version:

$Revision: 646777 $ $Date: 2008-04-10 14:33:15 +0200 (Thu, 10 Apr 2008) $

Author:

Stephen Colebourne

See Also:

Serialized Form

Nested Class Summary
- Nested classes/interfaces inherited from class org.apache.commons.collections.map.AbstractHashedMap
  AbstractHashedMap.EntrySet, AbstractHashedMap.EntrySetIterator, AbstractHashedMap.HashEntry, AbstractHashedMap.HashIterator, AbstractHashedMap.HashMapIterator, AbstractHashedMap.KeySet, AbstractHashedMap.KeySetIterator, AbstractHashedMap.Values, AbstractHashedMap.ValuesIterator
- Nested classes/interfaces inherited from class java.util.AbstractMap
  AbstractMap.SimpleEntry<K extends Object,V extends Object>, AbstractMap.SimpleImmutableEntry<K extends Object,V extends Object>
- Nested classes/interfaces inherited from interface java.util.Map
  Map.Entry<K extends Object,V extends Object>

Field Summary
- Fields inherited from class org.apache.commons.collections.map.AbstractHashedMap
  data, DEFAULT_CAPACITY, DEFAULT_LOAD_FACTOR, DEFAULT_THRESHOLD, entrySet, GETKEY_INVALID, GETVALUE_INVALID, keySet, loadFactor, MAXIMUM_CAPACITY, modCount, NO_NEXT_ENTRY, NO_PREVIOUS_ENTRY, NULL, REMOVE_INVALID, SETVALUE_INVALID, size, threshold, values

Constructor Summary

Constructors
Constructor	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 map)`	Constructor copying elements from another map.

Method Summary

All Methods Instance Methods Concrete Methods
Modifier and Type Method Description

Object clone()
Clones the map without cloning the keys or values.
- Methods inherited from class org.apache.commons.collections.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
- Methods inherited from interface java.util.Map
  compute, computeIfAbsent, computeIfPresent, forEach, getOrDefault, merge, putIfAbsent, remove, replace, replace, replaceAll

- 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 less than one
  - 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 less than one
    
    IllegalArgumentException - if the load factor is less than zero
  - HashedMap
```
public HashedMap(Map map)
```
    Constructor copying elements from another map.
    
    Parameters:
    
    map - the map to copy
    
    Throws:
    
    NullPointerException - if the map is null
- Method Detail
  - clone
```
public Object clone()
```
    Clones the map without cloning the keys or values.
    
    Overrides:
    
    clone in class AbstractHashedMap
    
    Returns:
    
    a shallow clone