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Java™ Platform Standard Ed. 6 |
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K - the type of keys maintained by this mapV - the type of mapped valuespublic interface ConcurrentMap<K,V>
A Map providing additional atomic
putIfAbsent, remove, and replace methods.
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.
This interface is a member of the Java Collections Framework.
| Nested Class Summary |
|---|
| Nested classes/interfaces inherited from interface java.util.Map |
|---|
Map.Entry<K,V> |
| Method Summary | |
|---|---|
V |
putIfAbsent(K key,
V value)
If the specified key is not already associated with a value, associate it with the given value. |
boolean |
remove(Object key,
Object value)
Removes the entry for a key only if currently mapped to a given value. |
V |
replace(K key,
V value)
Replaces the entry for a key only if currently mapped to some value. |
boolean |
replace(K key,
V oldValue,
V newValue)
Replaces the entry for a key only if currently mapped to a given value. |
| Methods inherited from interface java.util.Map |
|---|
clear, containsKey, containsValue, entrySet, equals, get, hashCode, isEmpty, keySet, put, putAll, remove, size, values |
| Method Detail |
|---|
V putIfAbsent(K key,
V value)
if (!map.containsKey(key))
return map.put(key, value);
else
return map.get(key);
except that the action is performed atomically.
key - key with which the specified value is to be associatedvalue - value to be associated with the specified key
UnsupportedOperationException - if the put operation
is not supported by this map
ClassCastException - if the class of the specified key or value
prevents it from being stored in this map
NullPointerException - if the specified key or value is null,
and this map does not permit null keys or values
IllegalArgumentException - if some property of the specified key
or value prevents it from being stored in this map
boolean remove(Object key,
Object value)
if (map.containsKey(key) && map.get(key).equals(value)) {
map.remove(key);
return true;
} else return false;
except that the action is performed atomically.
key - key with which the specified value is associatedvalue - value expected to be associated with the specified key
UnsupportedOperationException - if the remove operation
is not supported by this map
ClassCastException - if the key or value is of an inappropriate
type for this map (optional)
NullPointerException - if the specified key or value is null,
and this map does not permit null keys or values (optional)
boolean replace(K key,
V oldValue,
V newValue)
if (map.containsKey(key) && map.get(key).equals(oldValue)) {
map.put(key, newValue);
return true;
} else return false;
except that the action is performed atomically.
key - key with which the specified value is associatedoldValue - value expected to be associated with the specified keynewValue - value to be associated with the specified key
UnsupportedOperationException - if the put operation
is not supported by this map
ClassCastException - if the class of a specified key or value
prevents it from being stored in this map
NullPointerException - if a specified key or value is null,
and this map does not permit null keys or values
IllegalArgumentException - if some property of a specified key
or value prevents it from being stored in this map
V replace(K key,
V value)
if (map.containsKey(key)) {
return map.put(key, value);
} else return null;
except that the action is performed atomically.
key - key with which the specified value is associatedvalue - value to be associated with the specified key
UnsupportedOperationException - if the put operation
is not supported by this map
ClassCastException - if the class of the specified key or value
prevents it from being stored in this map
NullPointerException - if the specified key or value is null,
and this map does not permit null keys or values
IllegalArgumentException - if some property of the specified key
or value prevents it from being stored in this map
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Java™ Platform Standard Ed. 6 |
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Copyright 2006 Sun Microsystems, Inc. All rights reserved. Use is subject to license terms. Also see the documentation redistribution policy.