cn.hutool.cache.impl

Class LRUCache<K,V>

java.lang.Object

cn.hutool.cache.impl.AbstractCache<K,V>

cn.hutool.cache.impl.ReentrantCache<K,V>

cn.hutool.cache.impl.LRUCache<K,V>

Type Parameters:

K - 键类型

V - 值类型

All Implemented Interfaces:

Cache<K,V>, Serializable, Iterable<V>

public class LRUCache<K,V>
extends ReentrantCache<K,V>

LRU (least recently used)最近最久未使用缓存
根据使用时间来判定对象是否被持续缓存
当对象被访问时放入缓存，当缓存满了，最久未被使用的对象将被移除。
此缓存基于LinkedHashMap，因此当被缓存的对象每被访问一次，这个对象的key就到链表头部。
这个算法简单并且非常快，他比FIFO有一个显著优势是经常使用的对象不太可能被移除缓存。
缺点是当缓存满时，不能被很快的访问。

Author:

Looly,jodd

See Also:

Serialized Form

Field Summary

Fields inherited from class cn.hutool.cache.impl.ReentrantCache

lock

Fields inherited from class cn.hutool.cache.impl.AbstractCache

cacheMap, capacity, existCustomTimeout, hitCount, keyLockMap, listener, missCount, timeout

Constructor Summary

Constructors

Constructor and Description
LRUCache(int capacity) 构造 默认无超时
LRUCache(int capacity, long timeout) 构造

Method Summary

Modifier and Type	Method and Description
protected int	pruneCache() 只清理超时对象，LRU的实现会交给LinkedHashMap

Methods inherited from class cn.hutool.cache.impl.ReentrantCache

cacheObjIterator, clear, containsKey, get, prune, put, remove, toString

Methods inherited from class cn.hutool.cache.impl.AbstractCache

cacheObjIter, capacity, get, get, getHitCount, getMissCount, getWithoutLock, isEmpty, isFull, isPruneExpiredActive, iterator, keySet, onRemove, put, putWithoutLock, removeWithoutLock, setListener, size, timeout

Methods inherited from class java.lang.Object

clone, equals, finalize, getClass, hashCode, notify, notifyAll, wait, wait, wait

Methods inherited from interface cn.hutool.cache.Cache

get, get

Methods inherited from interface java.lang.Iterable

forEach, spliterator

Constructor Detail

LRUCache

public LRUCache(int capacity)

构造
默认无超时

Parameters:

capacity - 容量

LRUCache

public LRUCache(int capacity,
                long timeout)

构造

Parameters:

capacity - 容量

timeout - 默认超时时间，单位：毫秒

Method Detail

pruneCache

protected int pruneCache()

只清理超时对象，LRU的实现会交给LinkedHashMap

Specified by:

pruneCache in class AbstractCache<K,V>

Returns:

清理数