Class ReferenceIdentityMap

  • All Implemented Interfaces:
    java.util.Map

    public class ReferenceIdentityMap
    extends java.lang.Object
    implements java.util.Map
    Streamlined version of a WeakIdentityHashMap. Provides Identity semantics with Weak References to keys. This allows proxies to be GC'ed when no longer referenced by clients. BasicProxymanager.destroyProxy() need not be invoked when a proxy is no longer needed. Note that this is not a full Map implementation. The iteration and collection capabilities of Map have been discarded to keep the implementation lightweight.

    Much of this code was cribbed from the Commons Collection 3.1 implementation of ReferenceIdentityMap and AbstractReferenceMap.

    • Nested Class Summary

      • Nested classes/interfaces inherited from interface java.util.Map

        java.util.Map.Entry<K extends java.lang.Object,​V extends java.lang.Object>
    • Method Summary

      All Methods Instance Methods Concrete Methods 
      Modifier and Type Method Description
      void clear()
      Clears the map, resetting the size to zero and nullifying references to avoid garbage collection issues.
      boolean containsKey​(java.lang.Object key)
      Checks whether the map contains the specified key.
      boolean containsValue​(java.lang.Object value)
      Checks whether the map contains the specified value.
      java.util.Set entrySet()  
      java.lang.Object get​(java.lang.Object key)
      Gets the value mapped to the key specified.
      boolean isEmpty()
      Checks whether the map is currently empty.
      java.util.Set keySet()  
      java.lang.Object put​(java.lang.Object key, java.lang.Object value)
      Puts a key-value entry into this map.
      void putAll​(java.util.Map t)  
      java.lang.Object remove​(java.lang.Object key)
      Removes the specified mapping from this map.
      int size()
      Gets the size of the map.
      java.util.Collection values()  
      • Methods inherited from class java.lang.Object

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

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

      • size

        public int size()
        Gets the size of the map.
        Specified by:
        size in interface java.util.Map
        Returns:
        the size
      • isEmpty

        public boolean isEmpty()
        Checks whether the map is currently empty.
        Specified by:
        isEmpty in interface java.util.Map
        Returns:
        true if the map is currently size zero
      • containsKey

        public boolean containsKey​(java.lang.Object key)
        Checks whether the map contains the specified key.
        Specified by:
        containsKey in interface java.util.Map
        Parameters:
        key - the key to search for
        Returns:
        true if the map contains the key
      • containsValue

        public boolean containsValue​(java.lang.Object value)
        Checks whether the map contains the specified value.
        Specified by:
        containsValue in interface java.util.Map
        Parameters:
        value - the value to search for
        Returns:
        true if the map contains the value
      • get

        public java.lang.Object get​(java.lang.Object key)
        Gets the value mapped to the key specified.
        Specified by:
        get in interface java.util.Map
        Parameters:
        key - the key
        Returns:
        the mapped value, null if no match
      • put

        public java.lang.Object put​(java.lang.Object key,
                                    java.lang.Object value)
        Puts a key-value entry into this map. Neither the key nor the value may be null.
        Specified by:
        put in interface java.util.Map
        Parameters:
        key - the key to add, must not be null
        value - the value to add, must not be null
        Returns:
        the value previously mapped to this key, null if none
      • remove

        public java.lang.Object remove​(java.lang.Object key)
        Removes the specified mapping from this map.
        Specified by:
        remove in interface java.util.Map
        Parameters:
        key - the mapping to remove
        Returns:
        the value mapped to the removed key, null if key not in map
      • clear

        public void clear()
        Clears the map, resetting the size to zero and nullifying references to avoid garbage collection issues.
        Specified by:
        clear in interface java.util.Map
      • values

        public java.util.Collection values()
        Specified by:
        values in interface java.util.Map
      • putAll

        public void putAll​(java.util.Map t)
        Specified by:
        putAll in interface java.util.Map
      • entrySet

        public java.util.Set entrySet()
        Specified by:
        entrySet in interface java.util.Map
      • keySet

        public java.util.Set keySet()
        Specified by:
        keySet in interface java.util.Map