Apache Commons Collections 4.4 · org.apache.commons.collections4.map.HashedMap

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 java.util.Collections#synchronizedMap(Map). This class may throw exceptions when accessed by concurrent threads without synchronization.

Modifier and Type	Field and Description
private static final long	serialVersionUID Serialisation version

Constructor Summary

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

Method Summary

Modifier and Type	Method and Description
public HashedMap<K, V>	Returns: a shallow clone clone() Overrides org.apache.commons.collections4.map.AbstractHashedMap.clone. Clones the map without cloning the keys or values.
private void	readObject(final ObjectInputStream the input stream in) Read the map in using a custom routine.
private void	writeObject(final ObjectOutputStream the output stream out) Write the map out using a custom routine.

Field Detail

serialVersionUID	back to summary
private static final long serialVersionUID Serialisation version

Constructor Detail

HashedMap	back to summary
public HashedMap() Constructs a new empty map with default size and load factor.

HashedMap	back to summary
public HashedMap(final int initialCapacity) Constructs a new, empty map with the specified initial capacity. Parameters initialCapacity:int the initial capacity Exceptions IllegalArgumentException: if the initial capacity is negative

HashedMap

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public HashedMap(final int initialCapacity)

Constructs a new, empty map with the specified initial capacity.

Parameters

initialCapacity:int: the initial capacity

Exceptions

IllegalArgumentException:: if the initial capacity is negative

HashedMap	back to summary
public HashedMap(final int initialCapacity, final float loadFactor) Constructs a new, empty map with the specified initial capacity and load factor. Parameters initialCapacity:int the initial capacity loadFactor:float the load factor Exceptions IllegalArgumentException: if the initial capacity is negative if the load factor is less than zero

HashedMap

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public HashedMap(final int initialCapacity, final float loadFactor)

Constructs a new, empty map with the specified initial capacity and load factor.

Parameters

initialCapacity:int: the initial capacity
loadFactor:float: the load factor

Exceptions

IllegalArgumentException:

if the initial capacity is negative
if the load factor is less than zero

HashedMap	back to summary
public HashedMap(final Map<? extends K, ? extends V> map) Constructor copying elements from another map. Parameters map:Map<? extends K, ? extends V> the map to copy Exceptions NullPointerException: if the map is null

HashedMap

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

Constructor copying elements from another map.

Parameters

map:Map<? extends K, ? extends V>: the map to copy

Exceptions

NullPointerException:: if the map is null

Method Detail

clone	back to summary
public HashedMap<K, V> clone() Overrides org.apache.commons.collections4.map.AbstractHashedMap.clone. Clones the map without cloning the keys or values. Returns:HashedMap<K, V> a shallow clone Annotations @Override

clone

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public HashedMap<K, V> clone()

Overrides org.apache.commons.collections4.map.AbstractHashedMap.clone.

Clones the map without cloning the keys or values.

Returns:HashedMap<K, V>

a shallow clone

Annotations

@Override

readObject	back to summary
private void readObject(final ObjectInputStream in) throws IOException, ClassNotFoundException Read the map in using a custom routine. Parameters in:ObjectInputStream the input stream Exceptions IOException: if an error occurs while reading from the stream ClassNotFoundException: if an object read from the stream can not be loaded

readObject

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private void readObject(final ObjectInputStream in) throws IOException, ClassNotFoundException

Read the map in using a custom routine.

Parameters

in:ObjectInputStream: the input stream

Exceptions

IOException:: if an error occurs while reading from the stream
ClassNotFoundException:: if an object read from the stream can not be loaded

writeObject	back to summary
private void writeObject(final ObjectOutputStream out) throws IOException Write the map out using a custom routine. Parameters out:ObjectOutputStream the output stream Exceptions IOException: if an error occurs while writing to the stream

writeObject

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private void writeObject(final ObjectOutputStream out) throws IOException

Write the map out using a custom routine.

Parameters

out:ObjectOutputStream: the output stream

Exceptions

IOException:: if an error occurs while writing to the stream

public Class HashedMap<K, V>

Field Summary

Constructor Summary

Method Summary

Field Detail

Constructor Detail

Method Detail