Class CommonCache<K,​V>

  • Type Parameters:
    K - type of the keys
    V - type of the values
    All Implemented Interfaces:
    java.io.Serializable, java.util.Map<K,​V>, EvictableCache<K,​V>, MemoizeCache<K,​V>, ValueConvertable<V,​java.lang.Object>

    public class CommonCache<K,​V>
    extends java.lang.Object
    implements EvictableCache<K,​V>, ValueConvertable<V,​java.lang.Object>, java.io.Serializable
    Represents a simple key-value cache, which is NOT thread safe and backed by a Map instance
    Since:
    2.5.0
    See Also:
    Serialized Form
    • Constructor Summary

      Constructors 
      Constructor Description
      CommonCache()
      Constructs a cache with unlimited size
      CommonCache​(int maxSize)
      Constructs a LRU cache with the default initial capacity
      CommonCache​(int initialCapacity, int maxSize)
      Constructs a LRU cache with the specified initial capacity and max size.
      CommonCache​(int initialCapacity, int maxSize, EvictableCache.EvictionStrategy evictionStrategy)
      Constructs a cache with limited size
      CommonCache​(java.util.Map<K,​V> map)
      Constructs a cache backed by the specified Map instance
    • Method Summary

      All Methods Instance Methods Concrete Methods 
      Modifier and Type Method Description
      void cleanUpNullReferences()
      Invoked when some of the held SoftReferences have been evicted by the garbage collector and so should be removed from the cache.
      void clear()
      Clear the cache
      java.util.Map<K,​V> clearAll()
      Clear the cache
      boolean containsKey​(java.lang.Object key)
      Determines if the cache contains an entry for the specified key.
      boolean containsValue​(java.lang.Object value)  
      java.lang.Object convertValue​(V value)
      convert the original value to the target value
      java.util.Set<java.util.Map.Entry<K,​V>> entrySet()  
      V get​(java.lang.Object key)
      Gets a value from the cache
      V getAndPut​(K key, MemoizeCache.ValueProvider<? super K,​? extends V> valueProvider)
      Try to get the value from cache.
      V getAndPut​(K key, MemoizeCache.ValueProvider<? super K,​? extends V> valueProvider, boolean shouldCache)  
      boolean isEmpty()  
      java.util.Set<K> keys()
      Get all keys associated to cached values
      java.util.Set<K> keySet()  
      V put​(K key, V value)
      Associates the specified value with the specified key in the cache.
      void putAll​(java.util.Map<? extends K,​? extends V> m)  
      V remove​(java.lang.Object key)
      Remove the cached value by the key
      int size()
      Get the size of the cache
      java.lang.String toString()  
      java.util.Collection<V> values()
      Get all cached values
      • Methods inherited from class java.lang.Object

        clone, equals, finalize, getClass, hashCode, notify, notifyAll, wait, wait, wait
      • Methods inherited from interface java.util.Map

        compute, computeIfAbsent, computeIfPresent, equals, forEach, getOrDefault, hashCode, merge, putIfAbsent, remove, replace, replace, replaceAll
    • Field Detail

      • DEFAULT_LOAD_FACTOR

        public static final float DEFAULT_LOAD_FACTOR
        The default load factor
        See Also:
        Constant Field Values
      • DEFAULT_INITIAL_CAPACITY

        public static final int DEFAULT_INITIAL_CAPACITY
        The default initial capacity
        See Also:
        Constant Field Values
    • Constructor Detail

      • CommonCache

        public CommonCache()
        Constructs a cache with unlimited size
      • CommonCache

        public CommonCache​(int initialCapacity,
                           int maxSize,
                           EvictableCache.EvictionStrategy evictionStrategy)
        Constructs a cache with limited size
        Parameters:
        initialCapacity - initial capacity of the cache
        maxSize - max size of the cache
        evictionStrategy - LRU or FIFO, see EvictableCache.EvictionStrategy
      • CommonCache

        public CommonCache​(int initialCapacity,
                           int maxSize)
        Constructs a LRU cache with the specified initial capacity and max size. The LRU cache is slower than LRUCache
        Parameters:
        initialCapacity - initial capacity of the LRU cache
        maxSize - max size of the LRU cache
      • CommonCache

        public CommonCache​(int maxSize)
        Constructs a LRU cache with the default initial capacity
        Parameters:
        maxSize - max size of the LRU cache
        See Also:
        CommonCache(int, int)
      • CommonCache

        public CommonCache​(java.util.Map<K,​V> map)
        Constructs a cache backed by the specified Map instance
        Parameters:
        map - the Map instance
    • Method Detail

      • get

        public V get​(java.lang.Object key)
        Gets a value from the cache
        Specified by:
        get in interface java.util.Map<K,​V>
        Specified by:
        get in interface MemoizeCache<K,​V>
        Parameters:
        key - the key whose associated value is to be returned
        Returns:
        the value, or null, if it does not exist.
      • put

        public V put​(K key,
                     V value)
        Associates the specified value with the specified key in the cache.
        Specified by:
        put in interface java.util.Map<K,​V>
        Specified by:
        put in interface MemoizeCache<K,​V>
        Parameters:
        key - key with which the specified value is to be associated
        value - value to be associated with the specified key
        Returns:
        null, or the old value if the key associated with the specified key.
      • values

        public java.util.Collection<V> values()
        Get all cached values
        Specified by:
        values in interface EvictableCache<K,​V>
        Specified by:
        values in interface java.util.Map<K,​V>
        Returns:
        all cached values
      • entrySet

        public java.util.Set<java.util.Map.Entry<K,​V>> entrySet()
        Specified by:
        entrySet in interface java.util.Map<K,​V>
      • keys

        public java.util.Set<K> keys()
        Get all keys associated to cached values
        Specified by:
        keys in interface EvictableCache<K,​V>
        Returns:
        all keys
      • containsValue

        public boolean containsValue​(java.lang.Object value)
        Specified by:
        containsValue in interface java.util.Map<K,​V>
      • containsKey

        public boolean containsKey​(java.lang.Object key)
        Determines if the cache contains an entry for the specified key.
        Specified by:
        containsKey in interface EvictableCache<K,​V>
        Specified by:
        containsKey in interface java.util.Map<K,​V>
        Parameters:
        key - key whose presence in this cache is to be tested.
        Returns:
        true if the cache contains a mapping for the specified key
      • size

        public int size()
        Get the size of the cache
        Specified by:
        size in interface EvictableCache<K,​V>
        Specified by:
        size in interface java.util.Map<K,​V>
        Returns:
        the size of the cache
      • isEmpty

        public boolean isEmpty()
        Specified by:
        isEmpty in interface java.util.Map<K,​V>
      • remove

        public V remove​(java.lang.Object key)
        Remove the cached value by the key
        Specified by:
        remove in interface EvictableCache<K,​V>
        Specified by:
        remove in interface java.util.Map<K,​V>
        Parameters:
        key - of the cached value
        Returns:
        returns the removed value
      • putAll

        public void putAll​(java.util.Map<? extends K,​? extends V> m)
        Specified by:
        putAll in interface java.util.Map<K,​V>
      • keySet

        public java.util.Set<K> keySet()
        Specified by:
        keySet in interface java.util.Map<K,​V>
      • clearAll

        public java.util.Map<K,​V> clearAll()
        Clear the cache
        Specified by:
        clearAll in interface EvictableCache<K,​V>
        Returns:
        returns the content of the cleared map
      • clear

        public void clear()
        Clear the cache
        Specified by:
        clear in interface java.util.Map<K,​V>
        See Also:
        clearAll()
      • cleanUpNullReferences

        public void cleanUpNullReferences()
        Invoked when some of the held SoftReferences have been evicted by the garbage collector and so should be removed from the cache. The implementation must ensure that concurrent invocations of all methods on the cache may occur from other threads and thus should protect any shared resources.
        Specified by:
        cleanUpNullReferences in interface MemoizeCache<K,​V>
      • toString

        public java.lang.String toString()
        Overrides:
        toString in class java.lang.Object
      • convertValue

        public java.lang.Object convertValue​(V value)
        convert the original value to the target value
        Specified by:
        convertValue in interface ValueConvertable<K,​V>
        Parameters:
        value - the original value
        Returns:
        the converted value