MultiMap (Hazelcast Root 3.8 API)

All Superinterfaces:

BaseMultiMap<K,V>, DistributedObject

All Known Implementing Classes:

ClientMultiMapProxy, ObjectMultiMapProxy
```
public interface MultiMap<K,V>
extends BaseMultiMap<K,V>, DistributedObject
```
A specialized map whose keys can be associated with multiple values.

Gotchas:
- Methods -- including but not limited to get, containsKey, containsValue, remove, put, lock, and unlock -- do not use hashCode and equals implementations of the keys. Instead, they use hashCode and equals of the binary (serialized) forms of the objects.
- Methods -- including but not limited to get, remove, keySet, values, entrySet -- return a collection clone of the values. The collection is NOT backed by the map, so changes to the map are NOT reflected in the collection, and vice-versa.
Author:

oztalip

See Also:

IMap

Method Summary

All Methods Instance Methods Abstract Methods Deprecated Methods
Modifier and Type	Method and Description
`String`	`addEntryListener(EntryListener<K,V> listener, boolean includeValue)` Adds an entry listener for this multimap.
`String`	`addEntryListener(EntryListener<K,V> listener, K key, boolean includeValue)` Adds the specified entry listener for the specified key.
`String`	`addLocalEntryListener(EntryListener<K,V> listener)` Adds a local entry listener for this multimap.
`<SuppliedValue,Result> Result`	`aggregate(Supplier<K,V,SuppliedValue> supplier, Aggregation<K,SuppliedValue,Result> aggregation)` Deprecated. The old Aggregations API is superseded by Fast Aggregations (`com.hazelcast.aggregation`) which does not yet support MultiMap. Hazelcast Jet can be used in the future to replace this functionality.
`<SuppliedValue,Result> Result`	`aggregate(Supplier<K,V,SuppliedValue> supplier, Aggregation<K,SuppliedValue,Result> aggregation, JobTracker jobTracker)` Deprecated. The old Aggregations API is superseded by Fast Aggregations (`com.hazelcast.aggregation`) which does not yet support MultiMap. Hazelcast Jet can be used in the future to replace this functionality.
`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.
`void`	`forceUnlock(K key)` Releases the lock for the specified key regardless of the lock owner.
`Collection<V>`	`get(K key)` Returns the collection of values associated with the key.
`LocalMultiMapStats`	`getLocalMultiMapStats()` Returns `LocalMultiMapStats` for this map.
`String`	`getName()` Returns the name of this multimap.
`boolean`	`isLocked(K key)` Checks the lock for the specified key.
`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 a lock for the specified key.
`void`	`lock(K key, long leaseTime, TimeUnit timeUnit)` Acquires the lock for the specified key for the specified lease time.
`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.
`boolean`	`removeEntryListener(String registrationId)` Removes the specified entry listener.
`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.
`boolean`	`tryLock(K key, long time, TimeUnit timeunit, long leaseTime, TimeUnit leaseTimeunit)` Tries to acquire the lock for the specified key for the specified lease time.
`void`	`unlock(K key)` Releases the lock for the specified key.
`int`	`valueCount(K key)` Returns the number of values that match the given key in the multimap.
`Collection<V>`	`values()` Returns the collection of values in the multimap.

Methods inherited from interface com.hazelcast.core.DistributedObject
destroy, getPartitionKey, getServiceName

- Method Detail
  - getName
```
String getName()
```
    Returns the name of this multimap.
    
    Specified by:
    
    getName in interface DistributedObject
    
    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 the binary form of the key, not the actual implementations of hashCode and equals defined in the key's class.
    
    Specified by:
    
    put in interface BaseMultiMap<K,V>
    
    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 the binary form of the key, not the actual implementations of hashCode and equals defined in the 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.
    
    Specified by:
    
    get in interface BaseMultiMap<K,V>
    
    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 the binary form of the key, not the actual implementations of hashCode and equals defined in the key's class.
    
    Specified by:
    
    remove in interface BaseMultiMap<K,V>
    
    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 the binary form of the key, not the actual implementations of hashCode and equals defined in the 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.
    
    Specified by:
    
    remove in interface BaseMultiMap<K,V>
    
    Parameters:
    
    key - the key of the entries to remove
    
    Returns:
    
    the collection of removed values associated with the given key. The 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:
    
    the 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. The 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. the 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. The 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 the binary form of the key, not the actual implementations of hashCode and equals defined in the 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 the 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.
    
    Specified by:
    
    size in interface BaseMultiMap<K,V>
    
    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 the number of values that match the given key in the multimap.
    
    Warning:
    
    This method uses hashCode and equals of the binary form of the key, not the actual implementations of hashCode and equals defined in the key's class.
    
    Specified by:
    
    valueCount in interface BaseMultiMap<K,V>
    
    Parameters:
    
    key - the key whose values count is to be returned
    
    Returns:
    
    the number of values that match the given key in the multimap
  - addLocalEntryListener
```
String addLocalEntryListener(EntryListener<K,V> listener)
```
    Adds a local entry listener for this multimap. The 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 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 for this multimap
    
    Returns:
    
    returns registration id for the entry listener
    
    See Also:
    
    localKeySet()
  - addEntryListener
```
String addEntryListener(EntryListener<K,V> listener,
                        boolean includeValue)
```
    Adds an entry listener for this multimap. The listener will be notified for all multimap add/remove/update/evict events.
    
    Parameters:
    
    listener - entry listener for this multimap
    
    includeValue - true if EntryEvent should contain the value, false otherwise
    
    Returns:
    
    returns registration id for the entry listener
  - removeEntryListener
```
boolean removeEntryListener(String registrationId)
```
    Removes the specified entry listener. Returns silently if no such listener was added before.
    
    Parameters:
    
    registrationId - registration id of listener
    
    Returns:
    
    true if registration is removed, false otherwise
  - addEntryListener
```
String addEntryListener(EntryListener<K,V> listener,
                        K key,
                        boolean includeValue)
```
    Adds the specified entry listener for the specified key. The listener will be notified for all add/remove/update/evict events for the specified key only.
    
    Warning:
    
    This method uses hashCode and equals of the binary form of the key, not the actual implementations of hashCode and equals defined in the key's class.
    
    Parameters:
    
    listener - the entry listener
    
    key - the key to listen to
    
    includeValue - true if EntryEvent should contain the value, false otherwise
    
    Returns:
    
    returns registration id.
  - lock
```
void lock(K key)
```
    Acquires a 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.
    The scope of the lock is for this multimap only. The 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 the binary form of the key, not the actual implementations of hashCode and equals defined in the key's class.
    
    Parameters:
    
    key - the key to lock.
  - lock
```
void lock(K key,
          long leaseTime,
          TimeUnit timeUnit)
```
    Acquires the lock for the specified key for the specified lease time.
    After the lease time, the lock will be released.
    
    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 for this map only. The acquired lock is only for the key in this map.
    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 the binary form of the key, not the actual implementations of hashCode and equals defined in the key's class.
    
    Parameters:
    
    key - the key to lock.
    
    leaseTime - time to wait before releasing the lock.
    
    timeUnit - unit of time for the lease time.
  - isLocked
```
boolean isLocked(K key)
```
    Checks the lock for the specified key.
    If the lock is acquired, this method returns true, else it returns false.
    
    Warning:
    This method uses hashCode and equals of the binary form of the key, not the actual implementations of hashCode and equals defined in the key's class.
    
    Parameters:
    
    key - key to lock to be checked.
    
    Returns:
    
    true if the lock is acquired, false otherwise.
  - tryLock
```
boolean tryLock(K key)
```
    Tries to acquire the lock for the specified key.
    If the lock is not available, then the current thread does not wait and the method returns false immediately.
    
    Warning:
    
    This method uses hashCode and equals of the binary form of the key, not the actual implementations of hashCode and equals defined in the key's class.
    
    Parameters:
    
    key - the key to lock.
    
    Returns:
    
    true if lock is acquired, false otherwise.
  - tryLock
```
boolean tryLock(K key,
                long time,
                TimeUnit timeunit)
         throws InterruptedException
```
    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:
    - the lock is acquired by the current thread, or
    - the specified waiting time elapses.
    Warning:
    
    This method uses hashCode and equals of the binary form of the key, not the actual implementations of hashCode and equals defined in the 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, false if the waiting time elapsed before the lock was acquired.
    
    Throws:
    
    InterruptedException
  - tryLock
```
boolean tryLock(K key,
                long time,
                TimeUnit timeunit,
                long leaseTime,
                TimeUnit leaseTimeunit)
         throws InterruptedException
```
    Tries to acquire the lock for the specified key for the specified lease time.
    After lease time, the lock will be released.
    
    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:
    - the lock is acquired by the current thread, or
    - the specified waiting time elapses.
    Warning:
    This method uses hashCode and equals of the binary form of the key, not the actual implementations of hashCode and equals defined in the key's class.
    Parameters:
    
    key - key to lock in this map.
    
    time - maximum time to wait for the lock.
    
    timeunit - time unit of the time argument.
    
    leaseTime - time to wait before releasing the lock.
    
    leaseTimeunit - unit of time to specify lease time.
    
    Returns:
    
    true if the lock was acquired and false if the waiting time elapsed before the lock was acquired.
    
    Throws:
    
    NullPointerException - if the specified key is null.
    
    InterruptedException
  - 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 the binary form of the key, not the actual implementations of hashCode and equals defined in the key's class.
    
    Parameters:
    
    key - the key to lock.
  - forceUnlock
```
void forceUnlock(K key)
```
    Releases the lock for the specified key regardless of the lock owner. It always successfully unlocks the key, 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.
  - getLocalMultiMapStats
```
LocalMultiMapStats getLocalMultiMapStats()
```
    Returns LocalMultiMapStats for this map. LocalMultiMapStats is the statistics for the local portion of this distributed multi map and contains information such as ownedEntryCount backupEntryCount, lastUpdateTime, and lockedEntryCount.
    Since this stats are only for the local portion of this multi map, if you need the cluster-wide MultiMapStats, then you need to get the LocalMapStats from all members of the cluster and combine them.
    
    Returns:
    
    this multimap's local statistics.
  - aggregate
```
@Deprecated
<SuppliedValue,Result> Result aggregate(Supplier<K,V,SuppliedValue> supplier,
                                                    Aggregation<K,SuppliedValue,Result> aggregation)
```
    Deprecated. The old Aggregations API is superseded by Fast Aggregations (com.hazelcast.aggregation) which does not yet support MultiMap. Hazelcast Jet can be used in the future to replace this functionality.
    
    Executes a predefined aggregation on the multimaps data set. The Supplier is used to either select or to select and extract a (sub-)value. A predefined set of aggregations can be found in Aggregations.
    
    Type Parameters:
    
    SuppliedValue - the final type emitted from the supplier
    
    Result - the resulting aggregation value type
    
    Parameters:
    
    supplier - the supplier to select and / or extract a (sub-)value from the multimap
    
    aggregation - the aggregation that is being executed against the multimap
    
    Returns:
    
    Returns the aggregated value for the multimaps data set
  - aggregate
```
@Deprecated
<SuppliedValue,Result> Result aggregate(Supplier<K,V,SuppliedValue> supplier,
                                                    Aggregation<K,SuppliedValue,Result> aggregation,
                                                    JobTracker jobTracker)
```
    Deprecated. The old Aggregations API is superseded by Fast Aggregations (com.hazelcast.aggregation) which does not yet support MultiMap. Hazelcast Jet can be used in the future to replace this functionality.
    
    Executes a predefined aggregation on the multimaps data set. The Supplier is used to either select, or to select and extract, a (sub-)value. A predefined set of aggregations can be found in Aggregations.
    
    Type Parameters:
    
    SuppliedValue - the final type emitted from the supplier
    
    Result - the resulting aggregation value type
    
    Parameters:
    
    supplier - the supplier to select and / or extract a (sub-)value from the multimap
    
    aggregation - the aggregation that is being executed against the multimap
    
    jobTracker - the JobTracker instance to execute the aggregation
    
    Returns:
    
    Returns the aggregated value

Interface MultiMap<K,V>

Method Summary

Methods inherited from interface com.hazelcast.core.DistributedObject

Method Detail

getName

put

get

remove

remove

localKeySet

keySet

values

entrySet

containsKey

containsValue

containsEntry

size

clear

valueCount

addLocalEntryListener

addEntryListener

removeEntryListener

addEntryListener

lock

lock

isLocked

tryLock

tryLock

tryLock

unlock

forceUnlock

getLocalMultiMapStats

aggregate

aggregate