public Class CopyOnWriteMap<K, V>

Implements java.util.Map.clear.

Doc from java.util.Map.clear.

Removes all of the mappings from this map (optional operation). The map will be empty after this call returns.

Annotations

@Override

Implements java.util.Map.containsKey.

Doc from java.util.Map.containsKey.

Returns true if this map contains a mapping for the specified key. More formally, returns true if and only if this map contains a mapping for a key k such that Objects.equals(key, k). (There can be at most one such mapping.)

Parameters

key:Object

key whose presence in this map is to be tested

Returns:boolean

true if this map contains a mapping for the specified key

Annotations

@Override

Implements java.util.Map.containsValue.

Doc from java.util.Map.containsValue.

Returns true if this map maps one or more keys to the specified value. More formally, returns true if and only if this map contains at least one mapping to a value v such that Objects.equals(value, v). This operation will probably require time linear in the map size for most implementations of the Map interface.

Parameters

value:Object

value whose presence in this map is to be tested

Returns:boolean

true if this map maps one or more keys to the specified value

Annotations

@Override

Implements java.util.Map.entrySet.

Doc from java.util.Map.entrySet.

Returns a Set view of the mappings contained in this map. The set is backed by the map, so changes to the map are reflected in the set, and vice-versa. If the map is modified while an iteration over the set is in progress (except through the iterator's own remove operation, or through the setValue operation on a map entry returned by the iterator) the results of the iteration are undefined. The set supports element removal, which removes the corresponding mapping from the map, via the Iterator.remove, Set.remove, removeAll, retainAll and clear operations. It does not support the add or addAll operations.

Returns:Set<Map.Entry<K, V>>

a set view of the mappings contained in this map

Annotations

@Override

Implements java.util.Map.get.

Doc from java.util.Map.get.

Returns the value to which the specified key is mapped, or null if this map contains no mapping for the key.

More formally, if this map contains a mapping from a key k to a value v such that Objects.equals(key, k), then this method returns v; otherwise it returns null. (There can be at most one such mapping.)

If this map permits null values, then a return value of null does not necessarily indicate that the map contains no mapping for the key; it's also possible that the map explicitly maps the key to null. The containsKey operation may be used to distinguish these two cases.

Parameters

key:Object

the key whose associated value is to be returned

Returns:V

the value to which the specified key is mapped, or null if this map contains no mapping for the key

Annotations

@Override

Implements java.util.Map.isEmpty.

Doc from java.util.Map.isEmpty.

Returns true if this map contains no key-value mappings.

Returns:boolean

true if this map contains no key-value mappings

Annotations

@Override

Implements java.util.Map.keySet.

Doc from java.util.Map.keySet.

Returns a Set view of the keys contained in this map. The set is backed by the map, so changes to the map are reflected in the set, and vice-versa. If the map is modified while an iteration over the set is in progress (except through the iterator's own remove operation), the results of the iteration are undefined. The set supports element removal, which removes the corresponding mapping from the map, via the Iterator.remove, Set.remove, removeAll, retainAll, and clear operations. It does not support the add or addAll operations.

Returns:Set<K>

a set view of the keys contained in this map

Annotations

@Override

Implements java.util.Map.put.

Doc from java.util.Map.put.

Associates the specified value with the specified key in this map (optional operation). If the map previously contained a mapping for the key, the old value is replaced by the specified value. (A map m is said to contain a mapping for a key k if and only if m.containsKey(k) would return true.)

Parameters

key:K

key with which the specified value is to be associated

value:V

value to be associated with the specified key

Returns:V

the previous value associated with key, or null if there was no mapping for key. (A null return can also indicate that the map previously associated null with key, if the implementation supports null values.)

Annotations

@Override

Implements java.util.Map.putAll.

Doc from java.util.Map.putAll.

Copies all of the mappings from the specified map to this map (optional operation). The effect of this call is equivalent to that of calling put(k, v) on this map once for each mapping from key k to value v in the specified map. The behavior of this operation is undefined if the specified map is modified while the operation is in progress. If the specified map has a defined encounter order, processing of its mappings generally occurs in that order.

Parameters

m:Map<? extends K, ? extends V>

mappings to be stored in this map

Annotations

@Override

Implements java.util.concurrent.ConcurrentMap.putIfAbsent.

Doc from java.util.concurrent.ConcurrentMap.putIfAbsent.

If the specified key is not already associated with a value, associates it with the given value. This is equivalent to, for this map:

 if (!map.containsKey(key))
  return map.put(key, value);
else
  return map.get(key);

Parameters

key:K

key with which the specified value is to be associated

value:V

value to be associated with the specified key

Returns:V

the previous value associated with the specified key, or null if there was no mapping for the key. (A null return can also indicate that the map previously associated null with the key, if the implementation supports null values.)

Annotations

@Override

Implements java.util.concurrent.ConcurrentMap.remove.

Doc from java.util.concurrent.ConcurrentMap.remove.

Removes the entry for a key only if currently mapped to a given value. This is equivalent to, for this map:

 if (map.containsKey(key)
    && Objects.equals(map.get(key), value)) {
  map.remove(key);
  return true;
} else {
  return false;
}

Parameters

key:Object

key with which the specified value is associated

value:Object

value expected to be associated with the specified key

Returns:boolean

true if the value was removed

Annotations

@Override

Implements java.util.Map.remove.

Doc from java.util.Map.remove.

Removes the mapping for a key from this map if it is present (optional operation). More formally, if this map contains a mapping from key k to value v such that Objects.equals(key, k), that mapping is removed. (The map can contain at most one such mapping.)

Returns the value to which this map previously associated the key, or null if the map contained no mapping for the key.

If this map permits null values, then a return value of null does not necessarily indicate that the map contained no mapping for the key; it's also possible that the map explicitly mapped the key to null.

The map will not contain a mapping for the specified key once the call returns.

Parameters

key:Object

key whose mapping is to be removed from the map

Returns:V

the previous value associated with key, or null if there was no mapping for key.

Annotations

@Override

Implements java.util.concurrent.ConcurrentMap.replace.

Doc from java.util.concurrent.ConcurrentMap.replace.

Replaces the entry for a key only if currently mapped to a given value. This is equivalent to, for this map:

 if (map.containsKey(key)
    && Objects.equals(map.get(key), oldValue)) {
  map.put(key, newValue);
  return true;
} else {
  return false;
}

Parameters

key:K

key with which the specified value is associated

oldValue:V

value expected to be associated with the specified key

newValue:V

value to be associated with the specified key

Returns:boolean

true if the value was replaced

Annotations

@Override

Implements java.util.concurrent.ConcurrentMap.replace.

Doc from java.util.concurrent.ConcurrentMap.replace.

Replaces the entry for a key only if currently mapped to some value. This is equivalent to, for this map:

 if (map.containsKey(key))
  return map.put(key, value);
else
  return null;

Parameters

key:K

key with which the specified value is associated

value:V

value to be associated with the specified key

Returns:V

the previous value associated with the specified key, or null if there was no mapping for the key. (A null return can also indicate that the map previously associated null with the key, if the implementation supports null values.)

Annotations

@Override

Implements java.util.Map.size.

Doc from java.util.Map.size.

Returns the number of key-value mappings in this map. If the map contains more than Integer.MAX_VALUE elements, returns Integer.MAX_VALUE.

Returns:int

the number of key-value mappings in this map

Annotations

@Override

Implements java.util.Map.values.

Doc from java.util.Map.values.

Returns a Collection view of the values contained in this map. The collection is backed by the map, so changes to the map are reflected in the collection, and vice-versa. If the map is modified while an iteration over the collection is in progress (except through the iterator's own remove operation), the results of the iteration are undefined. The collection supports element removal, which removes the corresponding mapping from the map, via the Iterator.remove, Collection.remove, removeAll, retainAll and clear operations. It does not support the add or addAll operations.

Returns:Collection<V>

a collection view of the values contained in this map

Annotations

@Override