Package com.aspectran.core.util.cache

Class ConcurrentLruCache<K,​V>

  • Type Parameters:
    K - the type of the key used for caching
    V - the type of the cached values
    All Implemented Interfaces:
    Cache<K,​V>
    public class ConcurrentLruCache<K,​V>
extends java.lang.Object
implements Cache<K,​V>
    A thread-safe LRU Cache with a fixed capacity. If the cache reaches the capacity, it discards the least recently used entry first.

    This implementation is backed by a ConcurrentHashMap for storing the cached values and a ConcurrentLinkedQueue for ordering the keys and choosing the least recently used key when the cache is at full capacity.

    Since:
    6.6.7

    • Constructor Summary

      Constructors 
      Constructor Description
      ConcurrentLruCache​(int capacity, java.util.function.Function<K,​V> generator)  

    • Method Summary

      All Methods Instance Methods Concrete Methods 
      Modifier and Type Method Description
      void clear()
      Removes all of the elements from this cache.
      V get​(K key)
      Gets an entry from the cache.
      boolean isEmpty()
      Returns true if this cache contains no key-value mappings.
      java.util.Set<K> keySet()
      Returns a Set view of the keys contained in this cache.
      void remove​(K key)
      Removes the specified element from this cache if it is present.
      int size()
      Returns the number of elements in this cache.

      • Methods inherited from class java.lang.Object

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

    • Constructor Detail

      • ConcurrentLruCache

        public ConcurrentLruCache​(int capacity,
                          java.util.function.Function<K,​V> generator)

    • Method Detail

      • get

        public V get​(K key)
        Description copied from interface: Cache
        Gets an entry from the cache.
        Specified by:
        get in interface Cache<K,​V>
        Parameters:
        key - the key whose associated value is to be returned
        Returns:
        the element, or null, if it does not exist

      • remove

        public void remove​(K key)
        Description copied from interface: Cache
        Removes the specified element from this cache if it is present.
        Specified by:
        remove in interface Cache<K,​V>
        Parameters:
        key - key with which the specified value is to be associated

      • clear

        public void clear()
        Description copied from interface: Cache
        Removes all of the elements from this cache.
        Specified by:
        clear in interface Cache<K,​V>

      • keySet

        public java.util.Set<K> keySet()
        Description copied from interface: Cache
        Returns a Set view of the keys contained in this cache.
        Specified by:
        keySet in interface Cache<K,​V>
        Returns:
        the set view

      • size

        public int size()
        Description copied from interface: Cache
        Returns the number of elements in this cache.
        Specified by:
        size in interface Cache<K,​V>
        Returns:
        the number of elements in this cache

      • isEmpty

        public boolean isEmpty()
        Description copied from interface: Cache
        Returns true if this cache contains no key-value mappings.
        Specified by:
        isEmpty in interface Cache<K,​V>
        Returns:
        true if this cache contains no key-value mappings