Class ReferenceIdentityMap

java.lang.Object

org.apache.xbean.propertyeditor.ReferenceIdentityMap

All Implemented Interfaces:

Map

public class ReferenceIdentityMap
extends Object
implements Map

Streamlined version of a WeakIdentityHashMap. Provides Identity semantics with Weak References to keys. This allows proxies to be GC'ed when no longer referenced by clients. BasicProxymanager.destroyProxy() need not be invoked when a proxy is no longer needed. Note that this is not a full Map implementation. The iteration and collection capabilities of Map have been discarded to keep the implementation lightweight.

Much of this code was cribbed from the Commons Collection 3.1 implementation of ReferenceIdentityMap and AbstractReferenceMap.

Nested Class Summary

Nested classes/interfaces inherited from interface Map

Map.Entry<K,V>

Constructor Summary

Constructors

Constructor	Description
ReferenceIdentityMap()

Method Summary

Modifier and Type	Method	Description
void	clear()	Clears the map, resetting the size to zero and nullifying references to avoid garbage collection issues.
boolean	containsKey(Object key)	Checks whether the map contains the specified key.
boolean	containsValue(Object value)	Checks whether the map contains the specified value.
Set	entrySet()
Object	get(Object key)	Gets the value mapped to the key specified.
boolean	isEmpty()	Checks whether the map is currently empty.
Set	keySet()
Object	put(Object key, Object value)	Puts a key-value entry into this map.
void	putAll(Map t)
Object	remove(Object key)	Removes the specified mapping from this map.
int	size()	Gets the size of the map.
Collection	values()

Methods inherited from class Object

clone, 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

Constructor Details

ReferenceIdentityMap

public ReferenceIdentityMap()

Method Details

size

public int size()

Gets the size of the map.

Specified by:

size in interface Map

Returns:

the size

isEmpty

public boolean isEmpty()

Checks whether the map is currently empty.

Specified by:

isEmpty in interface Map

Returns:

true if the map is currently size zero

containsKey

public boolean containsKey(Object key)

Checks whether the map contains the specified key.

Specified by:

containsKey in interface Map

Parameters:

key - the key to search for

Returns:

true if the map contains the key

containsValue

public boolean containsValue(Object value)

Checks whether the map contains the specified value.

Specified by:

containsValue in interface Map

Parameters:

value - the value to search for

Returns:

true if the map contains the value

get

public Object get(Object key)

Gets the value mapped to the key specified.

Specified by:

get in interface Map

Parameters:

key - the key

Returns:

the mapped value, null if no match

put

public Object put(Object key,
 Object value)

Puts a key-value entry into this map. Neither the key nor the value may be null.

Specified by:

put in interface Map

Parameters:

key - the key to add, must not be null

value - the value to add, must not be null

Returns:

the value previously mapped to this key, null if none

remove

public Object remove(Object key)

Removes the specified mapping from this map.

Specified by:

remove in interface Map

Parameters:

key - the mapping to remove

Returns:

the value mapped to the removed key, null if key not in map

clear

public void clear()

Clears the map, resetting the size to zero and nullifying references to avoid garbage collection issues.

Specified by:

clear in interface Map

values

public Collection values()

Specified by:

values in interface Map

putAll

public void putAll(Map t)

Specified by:

putAll in interface Map

entrySet

public Set entrySet()

Specified by:

entrySet in interface Map

keySet

public Set keySet()

Specified by:

keySet in interface Map