Class CopyOnWriteMap<K,V>

java.lang.Object

org.apache.mina.util.CopyOnWriteMap<K,V>

Type Parameters:

K - The key type

V - The value type

All Implemented Interfaces:

Cloneable, Map<K,V>

public class CopyOnWriteMap<K,V>
extends Object
implements Map<K,V>, Cloneable

A thread-safe version of Map in which all operations that change the Map are implemented by making a new copy of the underlying Map. While the creation of a new Map can be expensive, this class is designed for cases in which the primary function is to read data from the Map, not to modify the Map. Therefore the operations that do not cause a change to this class happen quickly and concurrently.

Nested Class Summary

Nested classes/interfaces inherited from interface Map

Map.Entry<K,V>

Field Summary

Fields

Modifier and Type	Field	Description
private Map<K,V>	internalMap

Constructor Summary

Constructors

Constructor	Description
CopyOnWriteMap()	Creates a new instance of CopyOnWriteMap.
CopyOnWriteMap(int initialCapacity)	Creates a new instance of CopyOnWriteMap with the specified initial size
CopyOnWriteMap(Map<K,V> data)	Creates a new instance of CopyOnWriteMap in which the initial data being held by this map is contained in the supplied map.

Method Summary

Modifier and Type	Method	Description
void	clear()	Removes all entries in this map.
Object	clone()
boolean	containsKey(Object key)
boolean	containsValue(Object value)
Set<Map.Entry<K,V>>	entrySet()	This method will return a read-only Set.
V	get(Object key)
boolean	isEmpty()
Set<K>	keySet()	This method will return a read-only Set.
V	put(K key, V value)	Adds the provided key and value to this map.
void	putAll(Map<? extends K, ? extends V> newData)	Inserts all the keys and values contained in the provided map to this map.
V	remove(Object key)	Removed the value and key from this map based on the provided key.
int	size()
Collection<V>	values()	This method will return a read-only Collection.

Methods inherited from class Object

equals, finalize, getClass, hashCode, notify, notifyAll, toString, wait, wait, wait

Methods inherited from interface Map

compute, computeIfAbsent, computeIfPresent, equals, forEach, getOrDefault, hashCode, merge, putIfAbsent, remove, replace, replace, replaceAll

Field Details

internalMap

private volatile Map<K,V> internalMap

Constructor Details

CopyOnWriteMap

public CopyOnWriteMap()

Creates a new instance of CopyOnWriteMap.

CopyOnWriteMap

public CopyOnWriteMap(int initialCapacity)

Creates a new instance of CopyOnWriteMap with the specified initial size

Parameters:

initialCapacity - The initial size of the Map.

CopyOnWriteMap

public CopyOnWriteMap(Map<K,V> data)

Creates a new instance of CopyOnWriteMap in which the initial data being held by this map is contained in the supplied map.

Parameters:

data - A Map containing the initial contents to be placed into this class.

Method Details

put

public V put(K key,
 V value)

Adds the provided key and value to this map.

Specified by:

put in interface Map<K,V>

See Also:

• Map.put(java.lang.Object, java.lang.Object)

remove

public V remove(Object key)

Removed the value and key from this map based on the provided key.

Specified by:

remove in interface Map<K,V>

See Also:

• Map.remove(java.lang.Object)

putAll

public void putAll(Map<? extends K, ? extends V> newData)

Inserts all the keys and values contained in the provided map to this map.

Specified by:

putAll in interface Map<K,V>

See Also:

• Map.putAll(java.util.Map)

clear

public void clear()

Removes all entries in this map.

Specified by:

clear in interface Map<K,V>

See Also:

• Map.clear()

size

public int size()

Specified by:

size in interface Map<K,V>

Returns:

the number of key/value pairs in this map.

See Also:

• Map.size()

isEmpty

public boolean isEmpty()

Specified by:

isEmpty in interface Map<K,V>

Returns:

true if this map is empty, otherwise false.

See Also:

• Map.isEmpty()

containsKey

public boolean containsKey(Object key)

Specified by:

containsKey in interface Map<K,V>

Returns:

true if this map contains the provided key, otherwise this method return false.

See Also:

• Map.containsKey(java.lang.Object)

containsValue

public boolean containsValue(Object value)

Specified by:

containsValue in interface Map<K,V>

Returns:

true if this map contains the provided value, otherwise this method returns false.

See Also:

• Map.containsValue(java.lang.Object)

get

public V get(Object key)

Specified by:

get in interface Map<K,V>

Returns:

the value associated with the provided key from this map.

See Also:

• Map.get(java.lang.Object)

keySet

public Set<K> keySet()

This method will return a read-only Set.

Specified by:

keySet in interface Map<K,V>

values

public Collection<V> values()

This method will return a read-only Collection.

Specified by:

values in interface Map<K,V>

entrySet

public Set<Map.Entry<K,V>> entrySet()

This method will return a read-only Set.

Specified by:

entrySet in interface Map<K,V>

clone

public Object clone()

Overrides:

clone in class Object