com.hazelcast.core
Interface MultiMap<K,V>

All Superinterfaces:
Instance

public interface MultiMap<K,V>
extends Instance

A specialized map whose keys can be associated with multiple values.

Gotchas:

Author:
oztalip
See Also:
IMap

Nested Class Summary
 
Nested classes/interfaces inherited from interface com.hazelcast.core.Instance
Instance.InstanceType
 
Method Summary
 void addEntryListener(EntryListener<K,V> listener, boolean includeValue)
          Adds an entry listener for this multimap.
 void addEntryListener(EntryListener<K,V> listener, K key, boolean includeValue)
          Adds the specified entry listener for the specified key.
 void addLocalEntryListener(EntryListener<K,V> listener)
          Adds a local entry listener for this multimap.
 void clear()
          Clears the multimap.
 boolean containsEntry(K key, V value)
          Returns whether the multimap contains the given key-value pair.
 boolean containsKey(K key)
          Returns whether the multimap contains an entry with the key.
 boolean containsValue(Object value)
          Returns whether the multimap contains an entry with the value.
 Set<Map.Entry<K,V>> entrySet()
          Returns the set of key-value pairs in the multimap.
 Collection<V> get(K key)
          Returns the collection of values associated with the key.
 String getName()
          Returns the name of this multimap.
 Set<K> keySet()
          Returns the set of keys in the multimap.
 Set<K> localKeySet()
          Returns the locally owned set of keys.
 void lock(K key)
          Acquires the lock for the specified key.
 boolean lockMap(long time, TimeUnit timeunit)
          Tries to acquire the lock for the entire map.
 boolean put(K key, V value)
          Stores a key-value pair in the multimap.
 Collection<V> remove(Object key)
          Removes all the entries with the given key.
 boolean remove(Object key, Object value)
          Removes the given key value pair from the multimap.
 void removeEntryListener(EntryListener<K,V> listener)
          Removes the specified entry listener Returns silently if there is no such listener added before.
 void removeEntryListener(EntryListener<K,V> listener, K key)
          Removes the specified entry listener for the specified key.
 int size()
          Returns the number of key-value pairs in the multimap.
 boolean tryLock(K key)
          Tries to acquire the lock for the specified key.
 boolean tryLock(K key, long time, TimeUnit timeunit)
          Tries to acquire the lock for the specified key.
 void unlock(K key)
          Releases the lock for the specified key.
 void unlockMap()
          Unlocks the map.
 int valueCount(K key)
          Returns number of values matching to given key in the multimap.
 Collection<V> values()
          Returns the collection of values in the multimap.
 
Methods inherited from interface com.hazelcast.core.Instance
destroy, getId, getInstanceType
 

Method Detail

getName

String getName()
Returns the name of this multimap.

Returns:
the name of this multimap

put

boolean put(K key,
            V value)
Stores a key-value pair in the multimap.

Warning:

This method uses hashCode and equals of binary form of the key, not the actual implementations of hashCode and equals defined in key's class.

Parameters:
key - the key to be stored
value - the value to be stored
Returns:
true if size of the multimap is increased, false if the multimap already contains the key-value pair.

get

Collection<V> get(K key)
Returns the collection of values associated with the key.

Warning:

This method uses hashCode and equals of binary form of the key, not the actual implementations of hashCode and equals defined in key's class.

Warning-2:

The collection is NOT backed by the map, so changes to the map are NOT reflected in the collection, and vice-versa.

Parameters:
key - the key whose associated values are to be returned
Returns:
the collection of the values associated with the key.

remove

boolean remove(Object key,
               Object value)
Removes the given key value pair from the multimap.

Warning:

This method uses hashCode and equals of binary form of the key, not the actual implementations of hashCode and equals defined in key's class.

Parameters:
key - the key of the entry to remove
value - the value of the entry to remove
Returns:
true if the size of the multimap changed after the remove operation, false otherwise.

remove

Collection<V> remove(Object key)
Removes all the entries with the given key.

Warning:

This method uses hashCode and equals of binary form of the key, not the actual implementations of hashCode and equals defined in key's class.

Warning-2:

The collection is NOT backed by the map, so changes to the map are NOT reflected in the collection, and vice-versa.

Parameters:
key - the key of the entries to remove
Returns:
the collection of removed values associated with the given key. Returned collection might be modifiable but it has no effect on the multimap

localKeySet

Set<K> localKeySet()
Returns the locally owned set of keys.

Each key in this map is owned and managed by a specific member in the cluster.

Note that ownership of these keys might change over time so that key ownerships can be almost evenly distributed in the cluster.

Warning:

The set is NOT backed by the map, so changes to the map are NOT reflected in the set, and vice-versa.

Returns:
locally owned keys.

keySet

Set<K> keySet()
Returns the set of keys in the multimap.

Warning:

The set is NOT backed by the map, so changes to the map are NOT reflected in the set, and vice-versa.

Returns:
the set of keys in the multimap. Returned set might be modifiable but it has no effect on the multimap

values

Collection<V> values()
Returns the collection of values in the multimap.

Warning:

The collection is NOT backed by the map, so changes to the map are NOT reflected in the collection, and vice-versa.

Returns:
the collection of values in the multimap. Returned collection might be modifiable but it has no effect on the multimap

entrySet

Set<Map.Entry<K,V>> entrySet()
Returns the set of key-value pairs in the multimap.

Warning:

The set is NOT backed by the map, so changes to the map are NOT reflected in the set, and vice-versa.

Returns:
the set of key-value pairs in the multimap. Returned set might be modifiable but it has no effect on the multimap

containsKey

boolean containsKey(K key)
Returns whether the multimap contains an entry with the key.

Warning:

This method uses hashCode and equals of binary form of the key, not the actual implementations of hashCode and equals defined in key's class.

Parameters:
key - the key whose existence is checked.
Returns:
true if the multimap contains an entry with the key, false otherwise.

containsValue

boolean containsValue(Object value)
Returns whether the multimap contains an entry with the value.

Parameters:
value - the value whose existence is checked.
Returns:
true if the multimap contains an entry with the value, false otherwise.

containsEntry

boolean containsEntry(K key,
                      V value)
Returns whether the multimap contains the given key-value pair.

This method uses hashCode and equals of binary form of the key, not the actual implementations of hashCode and equals defined in key's class.

Parameters:
key - the key whose existence is checked.
value - the value whose existence is checked.
Returns:
true if the multimap contains the key-value pair, false otherwise.

size

int size()
Returns the number of key-value pairs in the multimap.

Returns:
the number of key-value pairs in the multimap.

clear

void clear()
Clears the multimap. Removes all key-value pairs.


valueCount

int valueCount(K key)
Returns number of values matching to given key in the multimap.

Warning:

This method uses hashCode and equals of binary form of the key, not the actual implementations of hashCode and equals defined in key's class.

Parameters:
key - the key whose values count are to be returned
Returns:
number of values matching to given key in the multimap.

addLocalEntryListener

void addLocalEntryListener(EntryListener<K,V> listener)
Adds a local entry listener for this multimap. Added listener will be only listening for the events (add/remove/update) of the locally owned entries.

Note that entries in distributed multimap are partitioned across the cluster members; each member owns and manages the some portion of the entries. Owned entries are called local entries. This listener will be listening for the events of local entries. Let's say your cluster has member1 and member2. On member2 you added a local listener and from member1, you call multimap.put(key2, value2). If the key2 is owned by member2 then the local listener will be notified for the add/update event. Also note that entries can migrate to other nodes for load balancing and/or membership change.

Parameters:
listener - entry listener
See Also:
localKeySet()

addEntryListener

void addEntryListener(EntryListener<K,V> listener,
                      boolean includeValue)
Adds an entry listener for this multimap. Listener will get notified for all multimap add/remove/update/evict events.

Parameters:
listener - entry listener
includeValue - true if EntryEvent should contain the value.

removeEntryListener

void removeEntryListener(EntryListener<K,V> listener)
Removes the specified entry listener Returns silently if there is no such listener added before.

Parameters:
listener - entry listener

addEntryListener

void addEntryListener(EntryListener<K,V> listener,
                      K key,
                      boolean includeValue)
Adds the specified entry listener for the specified key. The listener will get notified for all add/remove/update/evict events of the specified key only.

Warning:

This method uses hashCode and equals of binary form of the key, not the actual implementations of hashCode and equals defined in key's class.

Parameters:
listener - entry listener
key - the key to listen
includeValue - true if EntryEvent should contain the value.

removeEntryListener

void removeEntryListener(EntryListener<K,V> listener,
                         K key)
Removes the specified entry listener for the specified key. Returns silently if there is no such listener added before for the key.

Warning:

This method uses hashCode and equals of binary form of the key, not the actual implementations of hashCode and equals defined in key's class.

Parameters:
listener -
key -

lock

void lock(K key)
Acquires the lock for the specified key.

If the lock is not available then the current thread becomes disabled for thread scheduling purposes and lies dormant until the lock has been acquired.

Scope of the lock is this multimap only. Acquired lock is only for the key in this multimap.

Locks are re-entrant so if the key is locked N times then it should be unlocked N times before another thread can acquire it.

Warning:

This method uses hashCode and equals of binary form of the key, not the actual implementations of hashCode and equals defined in key's class.

Parameters:
key - key to lock.

tryLock

boolean tryLock(K key)
Tries to acquire the lock for the specified key.

If the lock is not available then the current thread doesn't wait and returns false immediately.

Warning:

This method uses hashCode and equals of binary form of the key, not the actual implementations of hashCode and equals defined in key's class.

Parameters:
key - key to lock.
Returns:
true if lock is acquired, false otherwise.

tryLock

boolean tryLock(K key,
                long time,
                TimeUnit timeunit)
Tries to acquire the lock for the specified key.

If the lock is not available then the current thread becomes disabled for thread scheduling purposes and lies dormant until one of two things happens:

Warning:

This method uses hashCode and equals of binary form of the key, not the actual implementations of hashCode and equals defined in key's class.

Parameters:
time - the maximum time to wait for the lock
timeunit - the time unit of the time argument.
Returns:
true if the lock was acquired and false if the waiting time elapsed before the lock was acquired.

unlock

void unlock(K key)
Releases the lock for the specified key. It never blocks and returns immediately.

Warning:

This method uses hashCode and equals of binary form of the key, not the actual implementations of hashCode and equals defined in key's class.

Parameters:
key - key to lock.

lockMap

boolean lockMap(long time,
                TimeUnit timeunit)
Tries to acquire the lock for the entire map. The thread that locks the map can do all the operations but other threads in the cluster cannot operate on the map.

If the lock is not available then the current thread becomes disabled for thread scheduling purposes and lies dormant until one of two things happens:

Parameters:
time - the maximum time to wait for the lock
timeunit - the time unit of the time argument.
Returns:
true if the lock was acquired and false if the waiting time elapsed before the lock was acquired.

unlockMap

void unlockMap()
Unlocks the map. It never blocks and returns immediately.



Copyright 2008-2012 Hazel Ltd. All Rights Reserved.