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>
- Type Parameters:
K
- the type of the keys in this mapV
- the type of the values in this map
- All Implemented Interfaces:
Serializable
,Cloneable
,Map<K,
,V> Get<K,
,V> IterableGet<K,
,V> IterableMap<K,
,V> Put<K,
V>
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
- See Also:
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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> -
Field Summary
FieldsModifier and TypeFieldDescriptionprivate static final long
Serialisation versionFields inherited from class org.apache.commons.collections4.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
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Constructor Summary
ConstructorsConstructorDescriptionConstructs 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.Constructor copying elements from another map. -
Method Summary
Modifier and TypeMethodDescriptionclone()
Clones the map without cloning the keys or values.private void
Read the map in using a custom routine.private void
Write the map out using a custom routine.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
Methods inherited from interface java.util.Map
compute, computeIfAbsent, computeIfPresent, forEach, getOrDefault, merge, putIfAbsent, remove, replace, replace, replaceAll
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Field Details
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serialVersionUID
private static final long serialVersionUIDSerialisation version- See Also:
-
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Constructor Details
-
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 capacityloadFactor
- the load factor- Throws:
IllegalArgumentException
- if the initial capacity is negativeIllegalArgumentException
- if the load factor is less than zero
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HashedMap
Constructor copying elements from another map.- Parameters:
map
- the map to copy- Throws:
NullPointerException
- if the map is null
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Method Details
-
clone
Clones the map without cloning the keys or values.- Overrides:
clone
in classAbstractHashedMap<K,
V> - Returns:
- a shallow clone
-
writeObject
Write the map out using a custom routine.- Parameters:
out
- the output stream- Throws:
IOException
- if an error occurs while writing to the stream
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readObject
Read the map in using a custom routine.- Parameters:
in
- the input stream- Throws:
IOException
- if an error occurs while reading from the streamClassNotFoundException
- if an object read from the stream can not be loaded
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