ConcurrentMap

public interface ConcurrentMap implements Map<K, V>
Known Indirect Subclasses

A Map providing thread safety and atomicity guarantees.

To maintain the specified guarantees, default implementations of methods including putIfAbsent(K, V) inherited from Map must be overridden by implementations of this interface. Similarly, implementations of the collections returned by methods keySet(), values(), and entrySet() must override methods such as removeIf when necessary to preserve atomicity guarantees.

Memory consistency effects: As with other concurrent collections, actions in a thread prior to placing an object into a ConcurrentMap as a key or value happen-before actions subsequent to the access or removal of that object from the ConcurrentMap in another thread.

Public Method Summary

V
compute(K key, BiFunction<? super K, ? super V, ? extends V> remappingFunction)
Attempts to compute a mapping for the specified key and its current mapped value (or null if there is no current mapping).
V
computeIfAbsent(K key, Function<? super K, ? extends V> mappingFunction)
If the specified key is not already associated with a value (or is mapped to null), attempts to compute its value using the given mapping function and enters it into this map unless null.
V
computeIfPresent(K key, BiFunction<? super K, ? super V, ? extends V> remappingFunction)
If the value for the specified key is present and non-null, attempts to compute a new mapping given the key and its current mapped value.