org.apache.commons.collections
Class SoftRefHashMap
java.lang.Object
org.apache.commons.collections.SoftRefHashMap
- Map
public class SoftRefHashMap
extends java.lang.Object
implements Map
HashMap with SoftReference links to values which allows the values of the Map
to be garbage collected by the JVM if it becomes low on memory.
Derive from this class and
override the factory method
createReference()
method to make
a Map wrapped in other types of Reference.
A synchronized version can be obtained with:
Collections.synchronizedMap( theMapToSynchronize )
WARNING the values() and entrySet() methods require optimisation
like the standard
HashMap
implementations so that iteration
over this Map is efficient.
void | clear() - Clears all mappings
|
boolean | containsKey(Object key) - Answers whether the argument is in the domain of the mappings
|
boolean | containsValue(Object value) - Answers whether the argument is a Referenced value
|
protected Reference | createReference(Object referent) - Returns a reference to the argument.
|
Set | entrySet() - Returns a set view of the mappings in the wrapped map
|
boolean | equals(Object object) - Answers whether this map and the argument are 'the same'
|
Object | get(Object key) - Retrieves the referent of the Referenced value
|
protected Map | getMap() - Retrieves the wrapped HashMap
|
int | hashCode() - Calculates the hash code for this map
|
boolean | isEmpty() - Answers whether there are any mappings
|
Set | keySet() - Returns the domain of the mappings
|
void | purge() - Removes References that have had their referents garbage collected
|
Object | put(Object key, Object value) - Adds a key-value mapping, wrapping the value in a Reference
|
void | putAll(java.util.Map map) - Put all of the mappings in the argument into this wrapped map
|
Object | remove(Object key) - Removes a mapping from this map
|
int | size() - Returns the number of mappings in this map
|
Collection | values() - Returns a collection of the Referenced values
|
SoftRefHashMap
public SoftRefHashMap()
clear
public void clear()
Clears all mappings
containsKey
public boolean containsKey(Object key)
Answers whether the argument is in the domain of the mappings
containsValue
public boolean containsValue(Object value)
Answers whether the argument is a Referenced value
createReference
protected Reference createReference(Object referent)
Returns a reference to the argument.
Override this method to make wrapped maps for other Reference types
entrySet
public Set entrySet()
Returns a set view of the mappings in the wrapped map
equals
public boolean equals(Object object)
Answers whether this map and the argument are 'the same'
get
public Object get(Object key)
Retrieves the referent of the Referenced value
key
- The key with which to retrieve the value
getMap
protected Map getMap()
Retrieves the wrapped HashMap
hashCode
public int hashCode()
Calculates the hash code for this map
isEmpty
public boolean isEmpty()
Answers whether there are any mappings
keySet
public Set keySet()
Returns the domain of the mappings
purge
public void purge()
Removes References that have had their referents garbage collected
put
public Object put(Object key,
Object value)
Adds a key-value mapping, wrapping the value in a Reference
putAll
public void putAll(java.util.Map map)
Put all of the mappings in the argument into this wrapped map
remove
public Object remove(Object key)
Removes a mapping from this map
size
public int size()
Returns the number of mappings in this map
values
public Collection values()
Returns a collection of the Referenced values
Copyright © 2001-2004 Apache Software Foundation. Documenation generated ${TODAY}.