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Oracle® Coherence Java API Reference
Release 3.7.0.0

E18683-01


com.tangosol.util
Class WrapperCollections.ConcurrentWrapperMap

java.lang.Object
  extended by com.tangosol.util.WrapperCollections.ConcurrentWrapperMap

All Implemented Interfaces:
java.util.Map
Enclosing class:
WrapperCollections

public static class WrapperCollections.ConcurrentWrapperMap
extends java.lang.Object
implements java.util.Map

Map implementation which uses a ReadWriteLock to manage concurrent access to an underlying Map.

Since:
Coherence 3.7

Nested Class Summary

 

Nested classes/interfaces inherited from interface java.util.Map
java.util.Map.Entry

 

Field Summary
protected  java.util.Collection m_collValues
          The values collection.
protected  boolean m_fStrict
          Determines whether or not all of the Entry methods are protected; if set to true, then all Entry methods are protected.
protected  java.util.concurrent.locks.ReadWriteLock m_lock
          The read/write lock for concurrency control.
protected  java.util.concurrent.locks.Lock m_lockExclusive
          The exclusive lock for performing read/write operations.
protected  java.util.concurrent.locks.Lock m_lockShared
          The shared lock for performing read operations.
protected  java.util.Map m_mapDelegate
          The Map to which this wrapper delegates.
protected  java.util.Set m_setEntries
          The entry set.
protected  java.util.Set m_setKeys
          The key set.

 

Constructor Summary
  WrapperCollections.ConcurrentWrapperMap(java.util.Map map)
          Create an ConcurrentWrapperMap which delegates to the specified Map.
protected WrapperCollections.ConcurrentWrapperMap(java.util.Map map, java.util.concurrent.locks.ReadWriteLock lock)
          Create an ConcurrentWrapperMap which delegates to the specified Map.
protected WrapperCollections.ConcurrentWrapperMap(java.util.Map map, java.util.concurrent.locks.ReadWriteLock lock, boolean fStrict)
          Create an ConcurrentWrapperMap which delegates to the specified Map.

 

Method Summary
 void clear()
          Removes all mappings from this map (optional operation).
 boolean containsKey(java.lang.Object oKey)
          Returns true if this map contains a mapping for the specified key.
 boolean containsValue(java.lang.Object oValue)
          Returns true if this map maps one or more keys to the specified value.
 java.util.Set entrySet()
          Returns a set view of the mappings contained in this map.
 boolean equals(java.lang.Object oOther)
          Compares the specified object with this map for equality.
 java.lang.Object get(java.lang.Object oKey)
          Returns the value to which this map maps the specified key.
protected  java.util.Map getDelegate()
          Return the Map to which all operations should be delegated to.
protected  java.util.concurrent.locks.ReadWriteLock getLock()
          Return the ReadWriteLock that is used to manage concurrent access and modifications to the underlying map.
 int hashCode()
          Returns the hash code value for this map.
 boolean isEmpty()
          Returns true if this map contains no key-value mappings.
 java.util.Set keySet()
          Returns a set view of the keys contained in this map.
 java.lang.Object put(java.lang.Object oKey, java.lang.Object oValue)
          Associates the specified value with the specified key in this map (optional operation).
 void putAll(java.util.Map map)
          Copies all of the mappings from the specified map to this map (optional operation).
 java.lang.Object remove(java.lang.Object oKey)
          Removes the mapping for this key from this map if it is present (optional operation).
 int size()
          Returns the number of key-value mappings in this map.
 java.lang.String toString()
          
 java.util.Collection values()
          Returns a collection view of the values contained in this map.

 

Field Detail

m_mapDelegate

protected final java.util.Map m_mapDelegate
The Map to which this wrapper delegates.

m_lock

protected final java.util.concurrent.locks.ReadWriteLock m_lock
The read/write lock for concurrency control.

m_lockShared

protected final java.util.concurrent.locks.Lock m_lockShared
The shared lock for performing read operations.

m_lockExclusive

protected final java.util.concurrent.locks.Lock m_lockExclusive
The exclusive lock for performing read/write operations.

m_setKeys

protected java.util.Set m_setKeys
The key set.

m_setEntries

protected java.util.Set m_setEntries
The entry set.

m_collValues

protected java.util.Collection m_collValues
The values collection.

m_fStrict

protected final boolean m_fStrict
Determines whether or not all of the Entry methods are protected; if set to true, then all Entry methods are protected.

Constructor Detail

WrapperCollections.ConcurrentWrapperMap

public WrapperCollections.ConcurrentWrapperMap(java.util.Map map)
Create an ConcurrentWrapperMap which delegates to the specified Map.
Parameters:
map - the Map to delegate all calls to

WrapperCollections.ConcurrentWrapperMap

protected WrapperCollections.ConcurrentWrapperMap(java.util.Map map,
                                                  java.util.concurrent.locks.ReadWriteLock lock)
Create an ConcurrentWrapperMap which delegates to the specified Map.
Parameters:
map - the Map to delegate all calls to
lock - a read/write lock for concurrency management

WrapperCollections.ConcurrentWrapperMap

protected WrapperCollections.ConcurrentWrapperMap(java.util.Map map,
                                                  java.util.concurrent.locks.ReadWriteLock lock,
                                                  boolean fStrict)
Create an ConcurrentWrapperMap which delegates to the specified Map.
Parameters:
map - the Map to delegate all calls to
lock - a read/write lock for concurrency management
fStrict - pass true to protect all Entry methods; false to protect only the setValue() method

Method Detail

getDelegate

protected java.util.Map getDelegate()
Return the Map to which all operations should be delegated to.
Returns:
the wrapped Map

getLock

protected java.util.concurrent.locks.ReadWriteLock getLock()
Return the ReadWriteLock that is used to manage concurrent access and modifications to the underlying map.
Returns:
the ReadWriteLock

clear

public void clear()
Removes all mappings from this map (optional operation).
Specified by:
clear in interface java.util.Map

containsKey

public boolean containsKey(java.lang.Object oKey)
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 (key==null ? k==null : key.equals(k)). (There can be at most one such mapping.)
Specified by:
containsKey in interface java.util.Map
Parameters:
oKey - key whose presence in this map is to be tested.
Returns:
true if this map contains a mapping for the specified key.

containsValue

public boolean containsValue(java.lang.Object oValue)
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 (value==null ? v==null : value.equals(v)). This operation will probably require time linear in the map size for most implementations of the Map interface.
Specified by:
containsValue in interface java.util.Map
Parameters:
oValue - value whose presence in this map is to be tested.
Returns:
true if this map maps one or more keys to the specified value.

entrySet

public java.util.Set entrySet()
Returns a set view of the mappings contained in this map. Each element in the returned set is a Map.Entry. 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.
Specified by:
entrySet in interface java.util.Map
Returns:
a set view of the mappings contained in this map.

get

public java.lang.Object get(java.lang.Object oKey)
Returns the value to which this map maps the specified key. Returns null if the map contains no mapping for this key. 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.

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

Specified by:
get in interface java.util.Map
Parameters:
oKey - key whose associated value is to be returned.
Returns:
the value to which this map maps the specified key, or null if the map contains no mapping for this key.
See Also:
Map.containsKey(Object)

isEmpty

public boolean isEmpty()
Returns true if this map contains no key-value mappings.
Specified by:
isEmpty in interface java.util.Map
Returns:
true if this map contains no key-value mappings.

keySet

public java.util.Set 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.
Specified by:
keySet in interface java.util.Map
Returns:
a set view of the keys contained in this map.

put

public java.lang.Object put(java.lang.Object oKey,
                            java.lang.Object oValue)
Associates the specified value with the specified key in this map (optional operation). If the map previously contained a mapping for this 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.))
Specified by:
put in interface java.util.Map
Parameters:
oKey - key with which the specified value is to be associated.
oValue - value to be associated with the specified key.
Returns:
previous value associated with specified key, or null if there was no mapping for key. A null return can also indicate that the map previously associated null with the specified key, if the implementation supports null values.

putAll

public void putAll(java.util.Map map)
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 unspecified if the specified map is modified while the operation is in progress.
Specified by:
putAll in interface java.util.Map
Parameters:
map - Mappings to be stored in this map.

remove

public java.lang.Object remove(java.lang.Object oKey)
Removes the mapping for this 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 (key==null ? k==null : key.equals(k)), that mapping is removed. (The map can contain at most one such mapping.)

Returns the value to which the map previously associated the key, or null if the map contained no mapping for this key. (A null return can also indicate that the map previously associated null with the specified key if the implementation supports null values.) The map will not contain a mapping for the specified key once the call returns.

Specified by:
remove in interface java.util.Map
Parameters:
oKey - key whose mapping is to be removed from the map.
Returns:
previous value associated with specified key, or null if there was no mapping for key.

size

public int 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.
Specified by:
size in interface java.util.Map
Returns:
the number of key-value mappings in this map.

values

public java.util.Collection 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.
Specified by:
values in interface java.util.Map
Returns:
a collection view of the values contained in this map.

equals

public boolean equals(java.lang.Object oOther)
Compares the specified object with this map for equality. Returns true if the given object is also a map and the two Maps represent the same mappings. More formally, two maps t1 and t2 represent the same mappings if t1.entrySet().equals(t2.entrySet()). This ensures that the equals method works properly across different implementations of the Map interface.
Specified by:
equals in interface java.util.Map
Parameters:
oOther - object to be compared for equality with this map.
Returns:
true if the specified object is equal to this map.

hashCode

public int hashCode()
Returns the hash code value for this map. The hash code of a map is defined to be the sum of the hashCodes of each entry in the map's entrySet view. This ensures that t1.equals(t2) implies that t1.hashCode()==t2.hashCode() for any two maps t1 and t2, as required by the general contract of Object.hashCode.
Specified by:
hashCode in interface java.util.Map
Returns:
the hash code value for this map.
See Also:
Map.Entry.hashCode(), Object.hashCode(), Object.equals(Object), Map.equals(Object)

toString

public java.lang.String toString()

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Oracle® Coherence Java API Reference
Release 3.7.0.0

E18683-01


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