Class SoftValuesHashMap<K,V>

java.lang.Object

java.util.AbstractMap<K,V>

org.h2.util.SoftValuesHashMap<K,V>

Type Parameters:

K - the key type

V - the value type

All Implemented Interfaces:

Map<K,V>

public class SoftValuesHashMap<K,V>
extends AbstractMap<K,V>

Map which stores items using SoftReference. Items can be garbage collected and removed. It is not a general purpose cache, as it doesn't implement some methods, and others not according to the map definition, to improve speed.

Nested Class Summary

Nested Classes

Modifier and Type	Class	Description
private static class	SoftValuesHashMap.SoftValue<T>	A soft reference that has a hard reference to the key.

Nested classes/interfaces inherited from class AbstractMap

AbstractMap.SimpleEntry<K,V>, AbstractMap.SimpleImmutableEntry<K,V>

Nested classes/interfaces inherited from interface Map

Map.Entry<K,V>

Field Summary

Fields

Modifier and Type	Field	Description
private final Map<K, SoftValuesHashMap.SoftValue<V>>	map
private final ReferenceQueue<V>	queue

Constructor Summary

Constructors

Constructor	Description
SoftValuesHashMap()

Method Summary

Modifier and Type	Method	Description
void	clear()
Set<Map.Entry<K,V>>	entrySet()
V	get(Object key)
private void	processQueue()
V	put(K key, V value)	Store the object.
V	remove(Object key)	Remove an object.

Methods inherited from class AbstractMap

clone, containsKey, containsValue, equals, hashCode, isEmpty, keySet, putAll, size, toString, values

Methods inherited from class Object

finalize, getClass, notify, notifyAll, wait, wait, wait

Methods inherited from interface Map

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

Field Details

map

private final Map<K, SoftValuesHashMap.SoftValue<V>> map

queue

private final ReferenceQueue<V> queue

Constructor Details

SoftValuesHashMap

public SoftValuesHashMap()

Method Details

processQueue

private void processQueue()

get

public V get(Object key)

Specified by:

get in interface Map<K,V>

Overrides:

get in class AbstractMap<K,V>

put

public V put(K key,
 V value)

Store the object. The return value of this method is null or a SoftReference.

Specified by:

put in interface Map<K,V>

Overrides:

put in class AbstractMap<K,V>

Parameters:

key - the key

value - the value

Returns:

null or the old object.

remove

public V remove(Object key)

Remove an object.

Specified by:

remove in interface Map<K,V>

Overrides:

remove in class AbstractMap<K,V>

Parameters:

key - the key

Returns:

null or the old object

clear

public void clear()

Specified by:

clear in interface Map<K,V>

Overrides:

clear in class AbstractMap<K,V>

entrySet

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

Specified by:

entrySet in interface Map<K,V>

Specified by:

entrySet in class AbstractMap<K,V>