Class Object2ObjectMaps.EmptyMap<K,​V>

java.lang.Object
All Implemented Interfaces:
Function<K,​V>, Object2ObjectFunction<K,​V>, Object2ObjectMap<K,​V>, java.io.Serializable, java.lang.Cloneable, java.util.function.Function<K,​V>, java.util.Map<K,​V>
Direct Known Subclasses:
Object2ObjectSortedMaps.EmptySortedMap
Enclosing class:
Object2ObjectMaps

public static class Object2ObjectMaps.EmptyMap<K,​V>
extends Object2ObjectFunctions.EmptyFunction<K,​V>
implements Object2ObjectMap<K,​V>, java.io.Serializable, java.lang.Cloneable
An immutable class representing an empty type-specific map.

This class may be useful to implement your own in case you subclass a type-specific map.

See Also:
Serialized Form
  • Method Details

    • containsValue

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

      public V getOrDefault​(java.lang.Object key, V defaultValue)
      Description copied from interface: Object2ObjectFunction
      Returns the value associated by this function to the specified key, or give the specified value if not present.
      Specified by:
      getOrDefault in interface Function<K,​V>
      Specified by:
      getOrDefault in interface java.util.Map<K,​V>
      Specified by:
      getOrDefault in interface Object2ObjectFunction<K,​V>
      Specified by:
      getOrDefault in interface Object2ObjectMap<K,​V>
      Overrides:
      getOrDefault in class Object2ObjectFunctions.EmptyFunction<K,​V>
      Parameters:
      key - the key.
      defaultValue - the value to return if not present.
      Returns:
      the corresponding value, or defaultValue if no value was present for the given key.
      See Also:
      Function.getOrDefault(Object, Object)
    • putAll

      public void putAll​(java.util.Map<? extends K,​? extends V> m)
      Specified by:
      putAll in interface java.util.Map<K,​V>
    • object2ObjectEntrySet

      public ObjectSet<Object2ObjectMap.Entry<K,​V>> object2ObjectEntrySet()
      Description copied from interface: Object2ObjectMap
      Returns a type-specific set view of the mappings contained in this map.

      This method is necessary because there is no inheritance along type parameters: it is thus impossible to strengthen Map.entrySet() so that it returns an ObjectSet of type-specific entries (the latter makes it possible to access keys and values with type-specific methods).

      Specified by:
      object2ObjectEntrySet in interface Object2ObjectMap<K,​V>
      Returns:
      a type-specific set view of the mappings contained in this map.
      See Also:
      Map.entrySet()
    • keySet

      public ObjectSet<K> keySet()
      Description copied from interface: Object2ObjectMap
      Specified by:
      keySet in interface java.util.Map<K,​V>
      Specified by:
      keySet in interface Object2ObjectMap<K,​V>
      Returns:
      a set view of the keys contained in this map.
      See Also:
      Map.keySet()
    • values

      public ObjectCollection<V> values()
      Description copied from interface: Object2ObjectMap
      Specified by:
      values in interface java.util.Map<K,​V>
      Specified by:
      values in interface Object2ObjectMap<K,​V>
      Returns:
      a set view of the values contained in this map.
      See Also:
      Map.values()
    • forEach

      public void forEach​(java.util.function.BiConsumer<? super K,​? super V> consumer)
      Specified by:
      forEach in interface java.util.Map<K,​V>
      Specified by:
      forEach in interface Object2ObjectMap<K,​V>
    • clone

      public java.lang.Object clone()
      Overrides:
      clone in class Object2ObjectFunctions.EmptyFunction<K,​V>
    • isEmpty

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

      public int hashCode()
      Specified by:
      hashCode in interface java.util.Map<K,​V>
      Overrides:
      hashCode in class Object2ObjectFunctions.EmptyFunction<K,​V>
    • equals

      public boolean equals​(java.lang.Object o)
      Specified by:
      equals in interface java.util.Map<K,​V>
      Overrides:
      equals in class Object2ObjectFunctions.EmptyFunction<K,​V>
    • toString

      public java.lang.String toString()
      Overrides:
      toString in class Object2ObjectFunctions.EmptyFunction<K,​V>