org.jxmpp.util.cache

Class LruCache<K,V>

java.lang.Object

java.util.AbstractMap<K,V>

java.util.HashMap<K,V>

java.util.LinkedHashMap<K,V>

org.jxmpp.util.cache.LruCache<K,V>

All Implemented Interfaces:

Serializable, Cloneable, Map<K,V>, Cache<K,V>

public class LruCache<K,V>
extends LinkedHashMap<K,V>
implements Cache<K,V>

A specialized Map that is size-limited (using an LRU algorithm). The Map is thread-safe.

Author:

Matt Tucker, Florian Schmaus

See Also:

Serialized Form

Nested Class Summary

Nested classes/interfaces inherited from class java.util.AbstractMap

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

Constructor Summary

Constructors

Constructor and Description
LruCache(int maxSize) Create a new cache and specify the maximum size of for the cache in bytes, and the maximum lifetime of objects.

Method Summary

Modifier and Type	Method and Description
void	clear()
boolean	containsKey(Object key)
boolean	containsValue(Object value)
Set<Map.Entry<K,V>>	entrySet()
V	get(Object key)
long	getCacheHits()
long	getCacheMisses()
int	getMaxCacheSize()
boolean	isEmpty()
Set<K>	keySet()
V	put(K key, V value)
void	putAll(Map<? extends K,? extends V> m)
V	remove(Object key)
protected boolean	removeEldestEntry(Map.Entry<K,V> eldest)
void	setMaxCacheSize(int maxCacheSize)
int	size()
Collection<V>	values()

Methods inherited from class java.util.LinkedHashMap

forEach, getOrDefault, replaceAll

Methods inherited from class java.util.HashMap

clone, compute, computeIfAbsent, computeIfPresent, merge, putIfAbsent, remove, replace, replace

Methods inherited from class java.util.AbstractMap

equals, hashCode, toString

Methods inherited from class java.lang.Object

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

Methods inherited from interface java.util.Map

compute, computeIfAbsent, computeIfPresent, equals, hashCode, merge, putIfAbsent, remove, replace, replace

Constructor Detail

LruCache

public LruCache(int maxSize)

Create a new cache and specify the maximum size of for the cache in bytes, and the maximum lifetime of objects.

Parameters:

maxSize - the maximum number of objects the cache will hold. -1 means the cache has no max size.

Method Detail

removeEldestEntry

protected final boolean removeEldestEntry(Map.Entry<K,V> eldest)

Overrides:

removeEldestEntry in class LinkedHashMap<K,V>

put

public final V put(K key,
                   V value)

Specified by:

put in interface Map<K,V>

Specified by:

put in interface Cache<K,V>

Overrides:

put in class HashMap<K,V>

get

public final V get(Object key)

Specified by:

get in interface Map<K,V>

Specified by:

get in interface Cache<K,V>

Overrides:

get in class LinkedHashMap<K,V>

remove

public final V remove(Object key)

Specified by:

remove in interface Map<K,V>

Overrides:

remove in class HashMap<K,V>

clear

public final void clear()

Specified by:

clear in interface Map<K,V>

Overrides:

clear in class LinkedHashMap<K,V>

size

public final int size()

Specified by:

size in interface Map<K,V>

Overrides:

size in class HashMap<K,V>

isEmpty

public final boolean isEmpty()

Specified by:

isEmpty in interface Map<K,V>

Overrides:

isEmpty in class HashMap<K,V>

values

public final Collection<V> values()

Specified by:

values in interface Map<K,V>

Overrides:

values in class LinkedHashMap<K,V>

containsKey

public final boolean containsKey(Object key)

Specified by:

containsKey in interface Map<K,V>

Overrides:

containsKey in class HashMap<K,V>

putAll

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

Specified by:

putAll in interface Map<K,V>

Overrides:

putAll in class HashMap<K,V>

containsValue

public final boolean containsValue(Object value)

Specified by:

containsValue in interface Map<K,V>

Overrides:

containsValue in class LinkedHashMap<K,V>

entrySet

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

Specified by:

entrySet in interface Map<K,V>

Overrides:

entrySet in class LinkedHashMap<K,V>

keySet

public final Set<K> keySet()

Specified by:

keySet in interface Map<K,V>

Overrides:

keySet in class LinkedHashMap<K,V>

getCacheHits

public final long getCacheHits()

getCacheMisses

public final long getCacheMisses()

getMaxCacheSize

public final int getMaxCacheSize()

Specified by:

getMaxCacheSize in interface Cache<K,V>

setMaxCacheSize

public final void setMaxCacheSize(int maxCacheSize)

Specified by:

setMaxCacheSize in interface Cache<K,V>