Class CacheMap<K,​V>

  • All Implemented Interfaces:
    Map<K,​V>

    public class CacheMap<K,​V>
    extends Object
    implements Map<K,​V>
    Implements a useful caching map. It weakly references the keys, but strongly references the data. It works much like the WeakHashMap, in that when the keys are garbage collected, the data is removed from the map. The main difference is that keys used for lookups don't have to be "==" the same to maintain the data in the cache. Basically, lookups in this map use a ".equals" compare, but the keys are then stored with a "==" compare so if the original key is garbage collected, the other keys that may reference the data keep the data in the cache. Note that this implementation is not synchronized. Not even a little. 'Read-only' operations can trigger internal modifications. If you share this class between threads, you must protect every operation.
    • Constructor Detail

      • CacheMap

        public CacheMap()
    • Method Detail

      • clear

        public void clear()
        Specified by:
        clear in interface Map<K,​V>
      • containsKey

        public boolean containsKey​(Object key)
        Specified by:
        containsKey in interface Map<K,​V>
      • get

        public V get​(Object key)
        Specified by:
        get in interface Map<K,​V>
      • isEmpty

        public boolean isEmpty()
        Specified by:
        isEmpty in interface Map<K,​V>
      • keySet

        public Set<K> keySet()
        Specified by:
        keySet in interface Map<K,​V>
      • put

        public V put​(K key,
                     V value)
        Specified by:
        put in interface Map<K,​V>
      • putAll

        public void putAll​(Map<? extends K,​? extends V> t)
        Specified by:
        putAll in interface Map<K,​V>
      • remove

        public V remove​(Object key)
        Specified by:
        remove in interface Map<K,​V>
      • size

        public int size()
        Specified by:
        size in interface Map<K,​V>