JHCaching
Lightweight LRU Caching library with persistence
LRU caching map is Least Recent Used Map, (see Wiki), meaning that a Key,Value pair is stored in the cache, with a "expireTime", but every time the Key is retrieved (get method) the expire time is extended.
It is a simple POJO one jar library.
With complete documentation with examples and javadoc.
When the cache reaches is "maxSize" or a cleanup of the cache is performed (automatically by deamon thread dependent on the "LRUCachingMapConfiguration"),
it is the keys with least recent used...