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

Type Parameters:
K - key
V - value
All Superinterfaces:
BaseMap<K,V>, ConcurrentMap<K,V>, DistributedObject, Map<K,V>
All Known Implementing Classes:
ClientMapProxy, MapProxyImpl

public interface IMap<K,V>
extends ConcurrentMap<K,V>, BaseMap<K,V>

Concurrent, distributed, observable and queryable map.

This class is not a general-purpose ConcurrentMap implementation! While this class implements the Map interface, it intentionally violates Map's general contract, which mandates the use of the equals method when comparing objects. Instead of the equals method, this implementation compares the serialized byte version of the objects.

Gotchas:

This class does not allow null to be used as a key or value.

See Also:
ConcurrentMap

Nested Class Summary
 
Nested classes/interfaces inherited from interface java.util.Map
Map.Entry<K,V>
 
Method Summary
 String addEntryListener(EntryListener<K,V> listener, boolean includeValue)
          Adds an entry listener for this map.
 String addEntryListener(EntryListener<K,V> listener, K key, boolean includeValue)
          Adds the specified entry listener for the specified key.
 String addEntryListener(EntryListener<K,V> listener, Predicate<K,V> predicate, boolean includeValue)
          Adds an continuous entry listener for this map.
 String addEntryListener(EntryListener<K,V> listener, Predicate<K,V> predicate, K key, boolean includeValue)
          Adds an continuous entry listener for this map.
 void addIndex(String attribute, boolean ordered)
          Adds an index to this map for the specified entries so that queries can run faster.
 String addInterceptor(MapInterceptor interceptor)
          Adds an interceptor for this map.
 String addLocalEntryListener(EntryListener<K,V> listener)
          Adds a local entry listener for this map.
 String addLocalEntryListener(EntryListener<K,V> listener, Predicate<K,V> predicate, boolean includeValue)
          Adds a local entry listener for this map.
 String addLocalEntryListener(EntryListener<K,V> listener, Predicate<K,V> predicate, K key, boolean includeValue)
          Adds a local entry listener for this map.
<SuppliedValue,Result>
Result
aggregate(Supplier<K,V,SuppliedValue> supplier, Aggregation<K,SuppliedValue,Result> aggregation)
          Executes a predefined aggregation on the maps data set.
<SuppliedValue,Result>
Result
aggregate(Supplier<K,V,SuppliedValue> supplier, Aggregation<K,SuppliedValue,Result> aggregation, JobTracker jobTracker)
          Executes a predefined aggregation on the maps data set.
 void clear()
          This method clears the map and invokes MapStore.deleteAll(java.util.Collection)deleteAll on MapStore which, if connected to a database, will delete the records from that database.
 boolean containsKey(Object key)
          Returns true if this map contains an entry for the specified key.
 boolean containsValue(Object value)
          
 void delete(Object key)
          Removes the mapping for a key from this map if it is present (optional operation).
 Set<Map.Entry<K,V>> entrySet()
          Returns a Set clone of the mappings contained in this map.
 Set<Map.Entry<K,V>> entrySet(Predicate predicate)
          Queries the map based on the specified predicate and returns the matching entries.
 boolean evict(K key)
          Evicts the specified key from this map.
 void evictAll()
          Evicts all keys from this map except locked ones.
 Map<K,Object> executeOnEntries(EntryProcessor entryProcessor)
          Applies the user defined EntryProcessor to the all entries in the map.
 Map<K,Object> executeOnEntries(EntryProcessor entryProcessor, Predicate predicate)
          Applies the user defined EntryProcessor to the entries in the map which satisfies provided predicate.
 Object executeOnKey(K key, EntryProcessor entryProcessor)
          Applies the user defined EntryProcessor to the entry mapped by the key.
 Map<K,Object> executeOnKeys(Set<K> keys, EntryProcessor entryProcessor)
          Applies the user defined EntryProcessor to the entries mapped by the collection of keys.
 void flush()
          If this map has a MapStore, this method flushes all the local dirty entries by calling MapStore.storeAll() and/or MapStore.deleteAll()
 void forceUnlock(K key)
          Releases the lock for the specified key regardless of the lock owner.
 V get(Object key)
          Returns the value for the specified key, or null if this map does not contain this key.
 Map<K,V> getAll(Set<K> keys)
          Returns the entries for the given keys.
 Future<V> getAsync(K key)
          Asynchronously gets the given key.
 EntryView<K,V> getEntryView(K key)
          Returns the EntryView for the specified key.
 LocalMapStats getLocalMapStats()
          Returns LocalMapStats for this map.
 boolean isLocked(K key)
          Checks the lock for the specified key.
 Set<K> keySet()
          Returns a set clone of the keys contained in this map.
 Set<K> keySet(Predicate predicate)
          Queries the map based on the specified predicate and returns the keys of matching entries.
 void loadAll(boolean replaceExistingValues)
          Loads all keys into the store.
 void loadAll(Set<K> keys, boolean replaceExistingValues)
          Loads given keys.
 Set<K> localKeySet()
          Returns the locally owned set of keys.
 Set<K> localKeySet(Predicate predicate)
          Returns the keys of matching locally owned entries.
 void lock(K key)
          Acquires the 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.
 V put(K key, V value)
          Associates the specified value with the specified key in this map.
 V put(K key, V value, long ttl, TimeUnit timeunit)
          Puts an entry into this map with a given ttl (time to live) value.
 Future<V> putAsync(K key, V value)
          Asynchronously puts the given key and value.
 Future<V> putAsync(K key, V value, long ttl, TimeUnit timeunit)
          Asynchronously puts the given key and value into this map with a given ttl (time to live) value.
 V putIfAbsent(K key, V value)
          If the specified key is not already associated with a value, associate it with the given value.
 V putIfAbsent(K key, V value, long ttl, TimeUnit timeunit)
          Puts an entry into this map with a given ttl (time to live) value if the specified key is not already associated with a value.
 void putTransient(K key, V value, long ttl, TimeUnit timeunit)
          Same as #put(K, V, long, java.util.concurrent.TimeUnit) but MapStore, if defined, will not be called to store/persist the entry.
 V remove(Object key)
          Removes the mapping for a key from this map if it is present.
 boolean remove(Object key, Object value)
          Removes the entry for a key only if currently mapped to a given value.
 Future<V> removeAsync(K key)
          Asynchronously removes the given key.
 boolean removeEntryListener(String id)
          Removes the specified entry listener Returns silently if there is no such listener added before.
 void removeInterceptor(String id)
          Removes the given interceptor for this map.
 V replace(K key, V value)
          Replaces the entry for a key only if it is 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.
 void set(K key, V value)
          Puts an entry into this map.
 void set(K key, V value, long ttl, TimeUnit timeunit)
          Puts an entry into this map with a given ttl (time to live) value.
 Future submitToKey(K key, EntryProcessor entryProcessor)
          Applies the user defined EntryProcessor to the entry mapped by the key.
 void submitToKey(K key, EntryProcessor entryProcessor, ExecutionCallback callback)
          Applies the user defined EntryProcessor to the entry mapped by the key with specified ExecutionCallback to listen event status and returns immediately.
 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 tryPut(K key, V value, long timeout, TimeUnit timeunit)
          Tries to put the given key and value into this map within a specified timeout value.
 boolean tryRemove(K key, long timeout, TimeUnit timeunit)
          Tries to remove the entry with the given key from this map within specified timeout value.
 void unlock(K key)
          Releases the lock for the specified key.
 Collection<V> values()
          Returns a collection clone of the values contained in this map.
 Collection<V> values(Predicate predicate)
          Queries the map based on the specified predicate and returns the values of matching entries.
 
Methods inherited from interface java.util.Map
equals, hashCode, isEmpty, putAll, size
 
Methods inherited from interface com.hazelcast.core.BaseMap
isEmpty, size
 
Methods inherited from interface com.hazelcast.core.DistributedObject
destroy, getId, getName, getPartitionKey, getServiceName
 

Method Detail

containsKey

boolean containsKey(Object key)
Returns true if this map contains an entry for the specified key.

Warning:

ˆ 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. The key will be searched for first in memory and if not found, and if one is attributed, will then attempt to load the key via a MapLoader.

Specified by:
containsKey in interface BaseMap<K,V>
Specified by:
containsKey in interface Map<K,V>
Parameters:
key - The specified key.
Returns:
true if this map contains an entry for the specified key.
Throws:
NullPointerException - if the specified key is null

containsValue

boolean containsValue(Object value)

Specified by:
containsValue in interface Map<K,V>
Throws:
NullPointerException - if the specified value is null

get

V get(Object key)
Returns the value for the specified key, or null if this map does not contain this key.

Warning:

This method returns a clone of original value, modifying the returned value does not change the actual value in the map. One should put modified value back to make changes visible to all nodes.

      V value = map.get(key);
      value.updateSomeProperty();
      map.put(key, value);
 

Warning-2:

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.

Specified by:
get in interface BaseMap<K,V>
Specified by:
get in interface Map<K,V>
Parameters:
key - The specified key.
Returns:
The value for the specified key.
Throws:
NullPointerException - if the specified key is null

put

V put(K key,
      V value)
Associates the specified value with the specified key in this map. If the map previously contained a mapping for the key, the old value is replaced by the specified value.

Warning:

This method returns a clone of previous value, not the original (identically equal) value previously put into map.

Warning-2:

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.

Specified by:
put in interface BaseMap<K,V>
Specified by:
put in interface Map<K,V>
Parameters:
key - The specified key.
value - The value to associate with the key.
Returns:
Previous value associated with key or null if there was no mapping for key.
Throws:
NullPointerException - if the specified key or value is null

remove

V remove(Object key)
Removes the mapping for a key from this map if it is present.

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

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:

This method returns a clone of the previous value, not the original (identically equal) value previously put into map.

Specified by:
remove in interface BaseMap<K,V>
Specified by:
remove in interface Map<K,V>
Parameters:
key - Remove the mapping for this key.
Returns:
The previous value associated with key, or null if there was no mapping for key.
Throws:
NullPointerException - if the specified key is null

remove

boolean remove(Object key,
               Object value)
Removes the entry for a key only if currently mapped to a given value. This is equivalent to
   if (map.containsKey(key) && map.get(key).equals(value)) {
       map.remove(key);
       return true;
   } else return false;
except that the action is performed atomically.

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.

Specified by:
remove in interface BaseMap<K,V>
Specified by:
remove in interface ConcurrentMap<K,V>
Parameters:
key - The specified key.
value - Remove the key if it has this value.
Returns:
true if the value was removed.
Throws:
NullPointerException - if the specified key or value is null

delete

void delete(Object key)
Removes the mapping for a key from this map if it is present (optional operation).

Differently from remove(Object); this operation does not return removed value to avoid serialization cost of returned value.

If the removed value will not be used, delete operation should be preferred over remove operation for a better performance.

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

Warning:

This method breaks the contract of EntryListener. When an entry is removed by delete(), it fires an EntryEvent with a null oldValue.

Also listener with predicates, will have null values, so only keys can be queried via predicates.

Specified by:
delete in interface BaseMap<K,V>
Parameters:
key - key whose mapping is to be removed from the map
Throws:
ClassCastException - if the key is of an inappropriate type for this map (optional)
NullPointerException - if the specified key is null

flush

void flush()
If this map has a MapStore, this method flushes all the local dirty entries by calling MapStore.storeAll() and/or MapStore.deleteAll()


getAll

Map<K,V> getAll(Set<K> keys)
Returns the entries for the given keys. If any keys are not present in the Map, it will call MapLoader.loadAll(java.util.Collection).

Warning:

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

Warning-2:

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

Parameters:
keys - keys to get
Returns:
map of entries
Throws:
NullPointerException - if any of the specified keys are null

loadAll

void loadAll(boolean replaceExistingValues)
Loads all keys into the store. This is a batch load operation so that an implementation can optimize the multiple loads.

Parameters:
replaceExistingValues - when true existing values in the Map will be replaced by those loaded from the MapLoader void loadAll(boolean replaceExistingValues));
Since:
3.3

loadAll

void loadAll(Set<K> keys,
             boolean replaceExistingValues)
Loads given keys. This is a batch load operation so that an implementation can optimize the multiple loads.

Parameters:
keys - keys of the values entries to load
replaceExistingValues - when true existing values in the Map will be replaced by those loaded from the MapLoader
Since:
3.3

clear

void clear()
This method clears the map and invokes MapStore.deleteAll(java.util.Collection)deleteAll on MapStore which, if connected to a database, will delete the records from that database.

The MAP_CLEARED event is fired for any registered listeners. See EntryListener.mapCleared(MapEvent).

To clear a map without calling MapStore.deleteAll(java.util.Collection) use evictAll(). If you wish to clear the map only without calling deleteAll, use

Specified by:
clear in interface Map<K,V>
See Also:
evictAll()

getAsync

Future<V> getAsync(K key)
Asynchronously gets the given key. Future future = map.getAsync(key); // do some other stuff, when ready get the result Object value = future.get(); Future.get() will block until the actual map.get() completes. If the application requires timely response, then Future.get(timeout, timeunit) can be used. try{ Future future = map.getAsync(key); Object value = future.get(40, TimeUnit.MILLISECOND); }catch (TimeoutException t) { // time wasn't enough } ExecutionException is never thrown.

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 map entry
Returns:
Future from which the value of the key can be retrieved.
Throws:
NullPointerException - if the specified key is null
See Also:
Future

putAsync

Future<V> putAsync(K key,
                   V value)
Asynchronously puts the given key and value. Future future = map.putAsync(key, value); // do some other stuff, when ready get the result Object oldValue = future.get(); Future.get() will block until the actual map.put() completes. If the application requires a timely response, then you can use Future.get(timeout, timeunit). try{ Future future = map.putAsync(key, newValue); Object oldValue = future.get(40, TimeUnit.MILLISECOND); }catch (TimeoutException t) { // time wasn't enough } ExecutionException is never thrown.

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 map entry
value - the new value of the map entry
Returns:
Future from which the old value of the key can be retrieved.
Throws:
NullPointerException - if the specified key or value is null
See Also:
Future

putAsync

Future<V> putAsync(K key,
                   V value,
                   long ttl,
                   TimeUnit timeunit)
Asynchronously puts the given key and value into this map with a given ttl (time to live) value. Entry will expire and get evicted after the ttl. If ttl is 0, then the entry lives forever. Future future = map.putAsync(key, value, ttl, timeunit); // do some other stuff, when ready get the result Object oldValue = future.get(); Future.get() will block until the actual map.get() completes. If the application requires timely response, then Future.get(timeout, timeunit) can be used. try{ Future future = map.putAsync(key, newValue, ttl, timeunit); Object oldValue = future.get(40, TimeUnit.MILLISECOND); }catch (TimeoutException t) { // time wasn't enough } ExecutionException is never thrown.

Warning 1:

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:

Time resolution for TTL is seconds. Given TTL value is rounded to next closest second value.

Parameters:
key - the key of the map entry
value - the new value of the map entry
ttl - maximum time for this entry to stay in the map 0 means infinite.
timeunit - time unit for the ttl
Returns:
Future from which the old value of the key can be retrieved.
Throws:
NullPointerException - if the specified key or value is null
See Also:
Future

removeAsync

Future<V> removeAsync(K key)
Asynchronously removes 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.

Parameters:
key - The key of the map entry to remove.
Returns:
A Future from which the value removed from the map can be retrieved.
Throws:
NullPointerException - if the specified key is null

tryRemove

boolean tryRemove(K key,
                  long timeout,
                  TimeUnit timeunit)
Tries to remove the entry with the given key from this map within specified timeout value. If the key is already locked by another thread and/or member, then this operation will wait timeout amount for acquiring the lock.

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:

This method returns a clone of the previous value, not the original (identically equal) value previously put into the map.

Parameters:
key - key of the entry
timeout - maximum time to wait for acquiring the lock for the key
timeunit - time unit for the timeout
Returns:
true if the remove is successful, false otherwise.
Throws:
NullPointerException - if the specified key is null

tryPut

boolean tryPut(K key,
               V value,
               long timeout,
               TimeUnit timeunit)
Tries to put the given key and value into this map within a specified timeout value. If this method returns false, it means that the caller thread could not acquire the lock for the key within the timeout duration, thus the put operation is not successful.

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 of the entry
value - value of the entry
timeout - maximum time to wait
timeunit - time unit for the timeout
Returns:
true if the put is successful, false otherwise.
Throws:
NullPointerException - if the specified key or value is null

put

V put(K key,
      V value,
      long ttl,
      TimeUnit timeunit)
Puts an entry into this map with a given ttl (time to live) value. Entry will expire and get evicted after the ttl. If ttl is 0, then the entry lives forever.

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:

This method returns a clone of previous value, not the original (identically equal) value previously put into map.

Warning 3:

Time resolution for TTL is seconds. Given TTL value is rounded to the next closest second value.

Parameters:
key - key of the entry
value - value of the entry
ttl - maximum time for this entry to stay in the map 0 means infinite.
timeunit - time unit for the ttl
Returns:
old value of the entry
Throws:
NullPointerException - if the specified key or value is null

putTransient

void putTransient(K key,
                  V value,
                  long ttl,
                  TimeUnit timeunit)
Same as #put(K, V, long, java.util.concurrent.TimeUnit) but MapStore, if defined, will not be called to store/persist the entry. If ttl is 0, then the entry lives forever.

Warning 1:

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:

Time resolution for TTL is seconds. Given TTL value is rounded to next closest second value.

Parameters:
key - key of the entry
value - value of the entry
ttl - maximum time for this entry to stay in the map. 0 means infinite.
timeunit - time unit for the ttl
Throws:
NullPointerException - if the specified key or value is null

putIfAbsent

V putIfAbsent(K key,
              V value)
If the specified key is not already associated with a value, associate it with the given value. This is equivalent to
   if (!map.containsKey(key))
       return map.put(key, value);
   else
       return map.get(key);
except that the action is performed atomically.

Note:

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.

Also, this method returns a clone of the previous value, not the original (identically equal) value previously put into the map.

Specified by:
putIfAbsent in interface BaseMap<K,V>
Specified by:
putIfAbsent in interface ConcurrentMap<K,V>
Parameters:
key - The specified key.
value - The value to associate with the key when there is no previous value.
Returns:
a clone of the previous value
Throws:
NullPointerException - if the specified key or value is null

putIfAbsent

V putIfAbsent(K key,
              V value,
              long ttl,
              TimeUnit timeunit)
Puts an entry into this map with a given ttl (time to live) value if the specified key is not already associated with a value. Entry will expire and get evicted after the ttl.

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:

This method returns a clone of previous value, not the original (identically equal) value previously put into map.

Warning 3:

Time resolution for TTL is seconds. Given TTL value is rounded to next closest second value.

Parameters:
key - key of the entry
value - value of the entry
ttl - maximum time for this entry to stay in the map
timeunit - time unit for the ttl
Returns:
old value of the entry
Throws:
NullPointerException - if the specified key or value is null

replace

boolean replace(K key,
                V oldValue,
                V newValue)
Replaces the entry for a key only if currently mapped to a given value. This is equivalent to
   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.

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.

Specified by:
replace in interface BaseMap<K,V>
Specified by:
replace in interface ConcurrentMap<K,V>
Parameters:
key - The specified key.
oldValue - Replace the key value if it is the old value.
newValue - The new value to replace the old value.
Returns:
true if the value was replaced.
Throws:
NullPointerException - if any of the specified parameters are null

replace

V replace(K key,
          V value)
Replaces the entry for a key only if it is currently mapped to some value. This is equivalent to
   if (map.containsKey(key)) {
       return map.put(key, value);
   } else return null;
except that the action is performed atomically.

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:

This method returns a clone of previous value, not the original (identically equal) value previously put into map.

Specified by:
replace in interface BaseMap<K,V>
Specified by:
replace in interface ConcurrentMap<K,V>
Parameters:
key - The specified key.
value - The value to replace the previous value.
Returns:
The previous value associated with key, or null if there was no mapping for key.
Throws:
NullPointerException - if the specified key or value is null

set

void set(K key,
         V value)
Puts an entry into this map. Similar to put operation except that set doesn't return the old value which is more efficient.

Warning:

This method breaks the contract of EntryListener. When an entry is updated by set(), it fires an EntryEvent with a null oldValue.

Warning-2:

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.

Specified by:
set in interface BaseMap<K,V>
Parameters:
key - key of the entry
value - value of the entry
Throws:
NullPointerException - if the specified key or value is null

set

void set(K key,
         V value,
         long ttl,
         TimeUnit timeunit)
Puts an entry into this map with a given ttl (time to live) value. Entry will expire and get evicted after the ttl. If ttl is 0, then the entry lives forever. Similar to put operation except that set doesn't return the old value which is more efficient.

Warning 1:

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:

Time resolution for TTL is seconds. Given TTL value is rounded to next closest second value.

Parameters:
key - key of the entry
value - value of the entry
ttl - maximum time for this entry to stay in the map 0 means infinite.
timeunit - time unit for the ttl
Throws:
NullPointerException - if the specified key or value is null

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.

You get a lock whether the value is present in the map or not. Other threads (possibly on other systems) would block on their invoke of lock() until the non-existent key is unlocked. If the lock holder introduces the key to the map, the put() operation is not blocked. If a thread not holding a lock on the non-existent key tries to introduce the key while a lock exists on the non-existent key, the put() operation blocks until it is unlocked.

Scope of the lock is this map only. 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.

There is no lock timeout on this method. Locks will be held infinitely.

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.
Throws:
NullPointerException - if the specified key is null

lock

void lock(K key,
          long leaseTime,
          TimeUnit timeUnit)
Acquires the lock for the specified key for the specified lease time.

After lease time, 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 this map only. 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 binary form of the key, not the actual implementations of hashCode and equals defined in key's class.

Parameters:
key - the key to lock
leaseTime - time to wait before releasing the lock
timeUnit - unit of time to specify lease time
Throws:
NullPointerException - if the specified key is null

isLocked

boolean isLocked(K key)
Checks the lock for the specified key.

If the lock is acquired then returns true, else false.

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 that is checked for lock.
Returns:
true if lock is acquired, false otherwise.
Throws:
NullPointerException - if the specified key is null

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 - the key to lock.
Returns:
true if lock is acquired, false otherwise.
Throws:
NullPointerException - if the specified key is null

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:

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 in this map
time - maximum time to wait for the lock
timeunit - 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.
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.

If the current thread is the holder of this lock then the hold count is decremented. If the hold count is now zero then the lock is released. If the current thread is not the holder of this lock then IllegalMonitorStateException is thrown.

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 lock.
Throws:
NullPointerException - if the specified key is null
IllegalMonitorStateException - if the current thread does not hold this 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 - the key to lock.
Throws:
NullPointerException - if the specified key is null

addLocalEntryListener

String addLocalEntryListener(EntryListener<K,V> listener)
Adds a local entry listener for this map. The added listener will be only listening for the events (add/remove/update/evict) of the locally owned entries.

Note that entries in distributed map 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 map.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
Returns:
A UUID.randomUUID().toString() which is used as a key to remove the listener.
See Also:
localKeySet()

addLocalEntryListener

String addLocalEntryListener(EntryListener<K,V> listener,
                             Predicate<K,V> predicate,
                             boolean includeValue)
Adds a local entry listener for this map. The added listener will be only listening for the events (add/remove/update/evict) of the locally owned entries. Listener will get notified for map add/remove/update/evict events filtered by given predicate.

Parameters:
listener - entry listener
predicate - predicate for filtering entries
includeValue - true if EntryEvent should contain the value.
Returns:
A UUID.randomUUID().toString() which is used as a key to remove the listener.

addLocalEntryListener

String addLocalEntryListener(EntryListener<K,V> listener,
                             Predicate<K,V> predicate,
                             K key,
                             boolean includeValue)
Adds a local entry listener for this map. The added listener will be only listening for the events (add/remove/update/evict) of the locally owned entries. Listener will get notified for map add/remove/update/evict events filtered by given predicate.

Parameters:
listener - entry listener
predicate - predicate for filtering entries
key - key to listen
includeValue - true if EntryEvent should contain the value.
Returns:
A UUID.randomUUID().toString() which is used as a key to remove the listener.

addInterceptor

String addInterceptor(MapInterceptor interceptor)
Adds an interceptor for this map. Added interceptor will intercept operations and execute user defined methods and will cancel operations if user defined method throw exception.

Parameters:
interceptor - map interceptor
Returns:
id of registered interceptor

removeInterceptor

void removeInterceptor(String id)
Removes the given interceptor for this map. So it will not intercept operations anymore.

Parameters:
id - registration id of the map interceptor

addEntryListener

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

Parameters:
listener - the added entry listener for this map
includeValue - true if EntryEvent should contain the value.
Returns:
A UUID.randomUUID().toString() which is used as a key to remove the listener.

removeEntryListener

boolean removeEntryListener(String id)
Removes the specified entry listener Returns silently if there is no such listener added before.

Parameters:
id - id of registered 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 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 - specified entry listener
key - key to listen
includeValue - true if EntryEvent should contain the value.
Returns:
A UUID.randomUUID().toString() which is used as a key to remove the listener.
Throws:
NullPointerException - if the specified key is null

addEntryListener

String addEntryListener(EntryListener<K,V> listener,
                        Predicate<K,V> predicate,
                        boolean includeValue)
Adds an continuous entry listener for this map. Listener will get notified for map add/remove/update/evict events filtered by given predicate.

Parameters:
listener - the added continuous entry listener for this map
predicate - predicate for filtering entries
includeValue - true if EntryEvent should contain the value.
Returns:
A UUID.randomUUID().toString() which is used as a key to remove the listener.

addEntryListener

String addEntryListener(EntryListener<K,V> listener,
                        Predicate<K,V> predicate,
                        K key,
                        boolean includeValue)
Adds an continuous entry listener for this map. Listener will get notified for map add/remove/update/evict events filtered by given predicate.

Parameters:
listener - the continuous entry listener for this map
predicate - predicate for filtering entries
key - key to listen
includeValue - true if EntryEvent should contain the value.
Returns:
A UUID.randomUUID().toString() which is used as a key to remove the listener.

getEntryView

EntryView<K,V> getEntryView(K key)
Returns the EntryView for the specified key.

Warning:

This method returns a clone of original mapping, modifying the returned value does not change the actual value in the map. One should put modified value back to make changes visible to all nodes.

Warning-2:

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
Returns:
EntryView of the specified key
Throws:
NullPointerException - if the specified key is null
See Also:
EntryView

evict

boolean evict(K key)
Evicts the specified key from this map. If a MapStore is defined for this map, then the entry is not deleted from the underlying MapStore, evict only removes the entry from the memory.

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 specified key to evict from this map
Returns:
true if the key is evicted, false otherwise.
Throws:
NullPointerException - if the specified key is null

evictAll

void evictAll()
Evicts all keys from this map except locked ones.

If a MapStore is defined for this map, deleteAll is not called by this method. If you do want to deleteAll to be called use the clear() method.

The EVICT_ALL event is fired for any registered listeners. See EntryListener.mapEvicted(MapEvent) .

Since:
3.3
See Also:
clear()

keySet

Set<K> keySet()
Returns a set clone of the keys contained in this map. The set is NOT backed by the map, so changes to the map are NOT reflected in the set, and vice-versa.

Specified by:
keySet in interface Map<K,V>
Returns:
a set clone of the keys contained in this map

values

Collection<V> values()
Returns a collection clone of the values contained in this map. The collection is NOT backed by the map, so changes to the map are NOT reflected in the collection, and vice-versa.

Specified by:
values in interface Map<K,V>
Returns:
a collection clone of the values contained in this map

entrySet

Set<Map.Entry<K,V>> entrySet()
Returns a Set clone of the mappings contained in this map. The set is NOT backed by the map, so changes to the map are NOT reflected in the set, and vice-versa.

Specified by:
entrySet in interface Map<K,V>
Returns:
a set clone of the keys mappings in this map

keySet

Set<K> keySet(Predicate predicate)
Queries the map based on the specified predicate and returns the keys of matching entries.

Specified predicate runs on all members in parallel.

Warning:

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

Parameters:
predicate - specified query criteria
Returns:
result key set of the query

entrySet

Set<Map.Entry<K,V>> entrySet(Predicate predicate)
Queries the map based on the specified predicate and returns the matching entries.

Specified predicate runs on all members in parallel.

Warning:

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

Parameters:
predicate - specified query criteria
Returns:
result entry set of the query

values

Collection<V> values(Predicate predicate)
Queries the map based on the specified predicate and returns the values of matching entries.

Specified predicate runs on all members in parallel.

Warning:

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

Parameters:
predicate - specified query criteria
Returns:
result value collection of the query

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.

localKeySet

Set<K> localKeySet(Predicate predicate)
Returns the keys of matching locally owned entries.

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.

Parameters:
predicate - specified query criteria
Returns:
keys of matching locally owned entries.

addIndex

void addIndex(String attribute,
              boolean ordered)
Adds an index to this map for the specified entries so that queries can run faster.

Let's say your map values are Employee objects.

   public class Employee implements Serializable {
       private boolean active = false;
       private int age;
       private String name = null;
       // other fields.

       // getters setter

   }
 

If you are querying your values mostly based on age and active then you should consider indexing these fields.

   IMap imap = Hazelcast.getMap("employees");
   imap.addIndex("age", true);        // ordered, since we have ranged queries for this field
   imap.addIndex("active", false);    // not ordered, because boolean field cannot have range
 

Index attribute should either have a getter method or be public. You should also make sure to add the indexes before adding entries to this map.

Time to Index

Indexing time is executed in parallel on each partition by operation threads. The Map is not blocked during this operation.

The time taken in proportional to the size of the Map and the number Members.

Searches while indexes are being built

Until the index finishes being created, any searches for the attribute will use a full Map scan, thus avoiding using a partially built index and returning incorrect results.

Parameters:
attribute - index attribute of value
ordered - true if index should be ordered, false otherwise.

getLocalMapStats

LocalMapStats getLocalMapStats()
Returns LocalMapStats for this map. LocalMapStats is the statistics for the local portion of this distributed map and contains information such as ownedEntryCount backupEntryCount, lastUpdateTime, lockedEntryCount.

Since this stats are only for the local portion of this map, if you need the cluster-wide MapStats then you need to get the LocalMapStats from all members of the cluster and combine them.

Returns:
this map's local statistics.

executeOnKey

Object executeOnKey(K key,
                    EntryProcessor entryProcessor)
Applies the user defined EntryProcessor to the entry mapped by the key. Returns the the object which is result of the process() method of EntryProcessor.

Returns:
result of entry process.
Throws:
NullPointerException - if the specified key is null

executeOnKeys

Map<K,Object> executeOnKeys(Set<K> keys,
                            EntryProcessor entryProcessor)
Applies the user defined EntryProcessor to the entries mapped by the collection of keys. the results mapped by each key in the collection.

Returns:
result of entry process.
Throws:
NullPointerException - if the specified key is null

submitToKey

void submitToKey(K key,
                 EntryProcessor entryProcessor,
                 ExecutionCallback callback)
Applies the user defined EntryProcessor to the entry mapped by the key with specified ExecutionCallback to listen event status and returns immediately.

Parameters:
key - key to be processed
entryProcessor - processor to process the key
callback - to listen whether operation is finished or not

submitToKey

Future submitToKey(K key,
                   EntryProcessor entryProcessor)
Applies the user defined EntryProcessor to the entry mapped by the key. Returns immediately with a Future representing that task.

EntryProcessor is not cancellable, so calling Future.cancel() method won't cancel the operation of EntryProcessor.

Parameters:
key - key to be processed
entryProcessor - processor to process the key
Returns:
Future from which the result of the operation can be retrieved.
See Also:
Future

executeOnEntries

Map<K,Object> executeOnEntries(EntryProcessor entryProcessor)
Applies the user defined EntryProcessor to the all entries in the map. Returns the results mapped by each key in the map.


executeOnEntries

Map<K,Object> executeOnEntries(EntryProcessor entryProcessor,
                               Predicate predicate)
Applies the user defined EntryProcessor to the entries in the map which satisfies provided predicate. Returns the results mapped by each key in the map.


aggregate

<SuppliedValue,Result> Result aggregate(Supplier<K,V,SuppliedValue> supplier,
                                        Aggregation<K,SuppliedValue,Result> aggregation)
Executes a predefined aggregation on the maps 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 map
aggregation - the aggregation that is being executed against the map
Returns:
the aggregated value

aggregate

<SuppliedValue,Result> Result aggregate(Supplier<K,V,SuppliedValue> supplier,
                                        Aggregation<K,SuppliedValue,Result> aggregation,
                                        JobTracker jobTracker)
Executes a predefined aggregation on the maps 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 map
aggregation - the aggregation that is being executed against the map
jobTracker - the JobTracker instance to execute the aggregation
Returns:
the aggregated value


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