Class ObjectIdSubclassMap<V extends ObjectId>

  • Type Parameters:
    V - type of subclass of ObjectId that will be stored in the map.
    All Implemented Interfaces:
    java.lang.Iterable<V>

    public class ObjectIdSubclassMap<V extends ObjectId>
    extends java.lang.Object
    implements java.lang.Iterable<V>
    Fast, efficient map specifically for ObjectId subclasses.

    This map provides an efficient translation from any ObjectId instance to a cached subclass of ObjectId that has the same value.

    If object instances are stored in only one map, ObjectIdOwnerMap is a more efficient implementation.

    • Constructor Summary

      Constructors 
      Constructor Description
      ObjectIdSubclassMap()
      Create an empty map.
    • Method Summary

      All Methods Instance Methods Concrete Methods 
      Modifier and Type Method Description
      <Q extends V>
      void
      add​(Q newValue)
      Store an object for future lookup.
      <Q extends V>
      V
      addIfAbsent​(Q newValue)
      Store an object for future lookup.
      void clear()
      Remove all entries from this map.
      boolean contains​(AnyObjectId toFind)
      Returns true if this map contains the specified object.
      V get​(AnyObjectId toFind)
      Lookup an existing mapping.
      boolean isEmpty()  
      java.util.Iterator<V> iterator()  
      int size()  
      • Methods inherited from class java.lang.Object

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

        forEach, spliterator
    • Constructor Detail

      • ObjectIdSubclassMap

        public ObjectIdSubclassMap()
        Create an empty map.
    • Method Detail

      • clear

        public void clear()
        Remove all entries from this map.
      • get

        public V get​(AnyObjectId toFind)
        Lookup an existing mapping.
        Parameters:
        toFind - the object identifier to find.
        Returns:
        the instance mapped to toFind, or null if no mapping exists.
      • contains

        public boolean contains​(AnyObjectId toFind)
        Returns true if this map contains the specified object.
        Parameters:
        toFind - object to find.
        Returns:
        true if the mapping exists for this object; false otherwise.
      • add

        public <Q extends V> void add​(Q newValue)
        Store an object for future lookup.

        An existing mapping for must not be in this map. Callers must first call get(AnyObjectId) to verify there is no current mapping prior to adding a new mapping, or use addIfAbsent(ObjectId).

        Type Parameters:
        Q - type of instance to store.
        Parameters:
        newValue - the object to store.
      • addIfAbsent

        public <Q extends VV addIfAbsent​(Q newValue)
        Store an object for future lookup.

        Stores newValue, but only if there is not already an object for the same object name. Callers can tell if the value is new by checking the return value with reference equality:

         V obj = ...;
         boolean wasNew = map.addIfAbsent(obj) == obj;
         
        Type Parameters:
        Q - type of instance to store.
        Parameters:
        newValue - the object to store.
        Returns:
        newValue if stored, or the prior value already stored and that would have been returned had the caller used get(newValue) first.
      • size

        public int size()
        Returns:
        number of objects in map
      • isEmpty

        public boolean isEmpty()
        Returns:
        true if size() is 0.
      • iterator

        public java.util.Iterator<V> iterator()
        Specified by:
        iterator in interface java.lang.Iterable<V extends ObjectId>