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:

java.io.Serializable, java.lang.Cloneable, java.util.Map<K,V>, Cache<K,V>

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

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

See Also:

Serialized Form

Nested Class Summary

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

java.util.AbstractMap.SimpleEntry<K,V>, java.util.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(java.lang.Object key)
boolean	containsValue(java.lang.Object value)
java.util.Set<java.util.Map.Entry<K,V>>	entrySet()
V	get(java.lang.Object key) Deprecated.
long	getCacheHits() Get the number of cache hits.
long	getCacheMisses() Get the number of cache misses.
int	getMaxCacheSize() Return the maximum cache Size.
boolean	isEmpty()
java.util.Set<K>	keySet()
V	lookup(K key) Returns the value of the specified key, or null.
V	put(K key, V value) Put a value in the cache.
void	putAll(java.util.Map<? extends K,? extends V> m)
V	remove(java.lang.Object key)
protected boolean	removeEldestEntry(java.util.Map.Entry<K,V> eldest)
void	setMaxCacheSize(int maxCacheSize) Set the maximum cache size.
int	size()
java.util.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(java.util.Map.Entry<K,V> eldest)

Overrides:

removeEldestEntry in class java.util.LinkedHashMap<K,V>

put

public final V put(K key,
                   V value)

Description copied from interface: Cache

Put a value in the cache.

Specified by:

put in interface java.util.Map<K,V>

Specified by:

put in interface Cache<K,V>

Overrides:

put in class java.util.HashMap<K,V>

Parameters:

key - the key of the value.

value - the value.

Returns:

the previous value or null.

lookup

public final V lookup(K key)

Description copied from interface: Cache

Returns the value of the specified key, or null.

Specified by:

lookup in interface Cache<K,V>

Parameters:

key - the key.

Returns:

the value found in the cache, or null.

get

@Deprecated
public final V get(java.lang.Object key)

Deprecated.

Description copied from interface: Cache

Returns the value of the specified key, or null.

Specified by:

get in interface java.util.Map<K,V>

Specified by:

get in interface Cache<K,V>

Overrides:

get in class java.util.LinkedHashMap<K,V>

Parameters:

key - the key.

Returns:

the value found in the cache, or null.

remove

public final V remove(java.lang.Object key)

Specified by:

remove in interface java.util.Map<K,V>

Overrides:

remove in class java.util.HashMap<K,V>

clear

public final void clear()

Specified by:

clear in interface java.util.Map<K,V>

Overrides:

clear in class java.util.LinkedHashMap<K,V>

size

public final int size()

Specified by:

size in interface java.util.Map<K,V>

Overrides:

size in class java.util.HashMap<K,V>

isEmpty

public final boolean isEmpty()

Specified by:

isEmpty in interface java.util.Map<K,V>

Overrides:

isEmpty in class java.util.HashMap<K,V>

values

public final java.util.Collection<V> values()

Specified by:

values in interface java.util.Map<K,V>

Overrides:

values in class java.util.LinkedHashMap<K,V>

containsKey

public final boolean containsKey(java.lang.Object key)

Specified by:

containsKey in interface java.util.Map<K,V>

Overrides:

containsKey in class java.util.HashMap<K,V>

putAll

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

Specified by:

putAll in interface java.util.Map<K,V>

Overrides:

putAll in class java.util.HashMap<K,V>

containsValue

public final boolean containsValue(java.lang.Object value)

Specified by:

containsValue in interface java.util.Map<K,V>

Overrides:

containsValue in class java.util.LinkedHashMap<K,V>

entrySet

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

Specified by:

entrySet in interface java.util.Map<K,V>

Overrides:

entrySet in class java.util.LinkedHashMap<K,V>

keySet

public final java.util.Set<K> keySet()

Specified by:

keySet in interface java.util.Map<K,V>

Overrides:

keySet in class java.util.LinkedHashMap<K,V>

getCacheHits

public final long getCacheHits()

Get the number of cache hits.

Returns:

the number of cache hits.

getCacheMisses

public final long getCacheMisses()

Get the number of cache misses.

Returns:

the number of cache misses.

getMaxCacheSize

public final int getMaxCacheSize()

Description copied from interface: Cache

Return the maximum cache Size.

Specified by:

getMaxCacheSize in interface Cache<K,V>

Returns:

the maximum cache size.

setMaxCacheSize

public final void setMaxCacheSize(int maxCacheSize)

Description copied from interface: Cache

Set the maximum cache size.

Specified by:

setMaxCacheSize in interface Cache<K,V>

Parameters:

maxCacheSize - the new maximum cache size.