- Type Parameters:
- K- the type of keys maintained by this map
- V- the type of mapped values
- All Implemented Interfaces:
- Serializable,- Cloneable,- ConcurrentMap<K,,- V> - ConcurrentNavigableMap<K,,- V> - Map<K,,- V> - NavigableMap<K,,- V> - SequencedMap<K,,- V> - SortedMap<K,- V> 
ConcurrentNavigableMap implementation.
 The map is sorted according to the natural
 ordering of its keys, or by a Comparator provided at map
 creation time, depending on which constructor is used.
 This class implements a concurrent variant of SkipLists
 providing expected average log(n) time cost for the
 containsKey, get, put and
 remove operations and their variants.  Insertion, removal,
 update, and access operations safely execute concurrently by
 multiple threads.
 
Iterators and spliterators are weakly consistent.
Ascending key ordered views and their iterators are faster than descending ones.
All Map.Entry pairs returned by methods in this class
 and its views represent snapshots of mappings at the time they were
 produced. They do not support the Entry.setValue
 method. (Note however that it is possible to change mappings in the
 associated map using put, putIfAbsent, or
 replace, depending on exactly which effect you need.)
 
Beware that bulk operations putAll, equals,
 toArray, containsValue, and clear are
 not guaranteed to be performed atomically. For example, an
 iterator operating concurrently with a putAll operation
 might view only some of the added elements.
 
This class and its views and iterators implement all of the
 optional methods of the Map and Iterator
 interfaces. Like most other concurrent collections, this class does
 not permit the use of null keys or values because some
 null return values cannot be reliably distinguished from the absence of
 elements.
 
This class is a member of the Java Collections Framework.
- Since:
- 1.6
- See Also:
- 
Nested Class SummaryNested classes/interfaces declared in class java.util.AbstractMapAbstractMap.SimpleEntry<K,V>, AbstractMap.SimpleImmutableEntry<K, V> 
- 
Constructor SummaryConstructorsConstructorDescriptionConstructs a new, empty map, sorted according to the natural ordering of the keys.ConcurrentSkipListMap(Comparator<? super K> comparator) Constructs a new, empty map, sorted according to the specified comparator.ConcurrentSkipListMap(Map<? extends K, ? extends V> m) Constructs a new map containing the same mappings as the given map, sorted according to the natural ordering of the keys.ConcurrentSkipListMap(SortedMap<K, ? extends V> m) Constructs a new map containing the same mappings and using the same ordering as the specified sorted map.
- 
Method SummaryModifier and TypeMethodDescriptionceilingEntry(K key) Returns a key-value mapping associated with the least key greater than or equal to the given key, ornullif there is no such entry.ceilingKey(K key) Returns the least key greater than or equal to the given key, ornullif there is no such key.voidclear()Removes all of the mappings from this map.clone()Returns a shallow copy of thisConcurrentSkipListMapinstance.Comparator<? super K> Returns the comparator used to order the keys in this map, ornullif this map uses the natural ordering of its keys.Attempts to compute a mapping for the specified key and its current mapped value (ornullif there is no current mapping).computeIfAbsent(K key, Function<? super K, ? extends V> mappingFunction) If the specified key is not already associated with a value, attempts to compute its value using the given mapping function and enters it into this map unlessnull.computeIfPresent(K key, BiFunction<? super K, ? super V, ? extends V> remappingFunction) If the value for the specified key is present, attempts to compute a new mapping given the key and its current mapped value.booleancontainsKey(Object key) Returnstrueif this map contains a mapping for the specified key.booleancontainsValue(Object value) Returnstrueif this map maps one or more keys to the specified value.Returns a reverse orderNavigableSetview of the keys contained in this map.Returns a reverse order view of the mappings contained in this map.entrySet()Returns aSetview of the mappings contained in this map.booleanCompares the specified object with this map for equality.Returns a key-value mapping associated with the least key in this map, ornullif the map is empty.firstKey()Returns the first (lowest) key currently in this map.floorEntry(K key) Returns a key-value mapping associated with the greatest key less than or equal to the given key, ornullif there is no such key.Returns the greatest key less than or equal to the given key, ornullif there is no such key.Returns the value to which the specified key is mapped, ornullif this map contains no mapping for the key.getOrDefault(Object key, V defaultValue) Returns the value to which the specified key is mapped, or the given defaultValue if this map contains no mapping for the key.Returns a view of the portion of this map whose keys are strictly less thantoKey.Returns a view of the portion of this map whose keys are less than (or equal to, ifinclusiveis true)toKey.higherEntry(K key) Returns a key-value mapping associated with the least key strictly greater than the given key, ornullif there is no such key.Returns the least key strictly greater than the given key, ornullif there is no such key.booleanisEmpty()Returnstrueif this map contains no key-value mappings.keySet()Returns aNavigableSetview of the keys contained in this map.Returns a key-value mapping associated with the greatest key in this map, ornullif the map is empty.lastKey()Returns the last (highest) key currently in this map.lowerEntry(K key) Returns a key-value mapping associated with the greatest key strictly less than the given key, ornullif there is no such key.Returns the greatest key strictly less than the given key, ornullif there is no such key.If the specified key is not already associated with a value, associates it with the given value.Returns aNavigableSetview of the keys contained in this map.Removes and returns a key-value mapping associated with the least key in this map, ornullif the map is empty.Removes and returns a key-value mapping associated with the greatest key in this map, ornullif the map is empty.Associates the specified value with the specified key in this map.ThrowsUnsupportedOperationException.putIfAbsent(K key, V value) If the specified key is not already associated with a value, associates it with the given value.ThrowsUnsupportedOperationException.Removes the mapping for the specified key from this map if present.booleanRemoves the entry for a key only if currently mapped to a given value.Replaces the entry for a key only if currently mapped to some value.booleanReplaces the entry for a key only if currently mapped to a given value.intsize()Returns the number of key-value mappings in this map.Returns a view of the portion of this map whose keys range fromfromKeytotoKey.Returns a view of the portion of this map whose keys range fromfromKey, inclusive, totoKey, exclusive.Returns a view of the portion of this map whose keys are greater than or equal tofromKey.Returns a view of the portion of this map whose keys are greater than (or equal to, ifinclusiveis true)fromKey.values()Returns aCollectionview of the values contained in this map.Methods declared in interface java.util.concurrent.ConcurrentMapforEach, replaceAllMethods declared in interface java.util.NavigableMapreversedMethods declared in interface java.util.SequencedMapsequencedEntrySet, sequencedKeySet, sequencedValues
- 
Constructor Details- 
ConcurrentSkipListMappublic ConcurrentSkipListMap()Constructs a new, empty map, sorted according to the natural ordering of the keys.
- 
ConcurrentSkipListMapConstructs a new, empty map, sorted according to the specified comparator.- Parameters:
- comparator- the comparator that will be used to order this map. If- null, the natural ordering of the keys will be used.
 
- 
ConcurrentSkipListMapConstructs a new map containing the same mappings as the given map, sorted according to the natural ordering of the keys.- Parameters:
- m- the map whose mappings are to be placed in this map
- Throws:
- ClassCastException- if the keys in- mare not- Comparable, or are not mutually comparable
- NullPointerException- if the specified map or any of its keys or values are null
 
- 
ConcurrentSkipListMapConstructs a new map containing the same mappings and using the same ordering as the specified sorted map.- Parameters:
- m- the sorted map whose mappings are to be placed in this map, and whose comparator is to be used to sort this map
- Throws:
- NullPointerException- if the specified sorted map or any of its keys or values are null
 
 
- 
- 
Method Details- 
cloneReturns a shallow copy of thisConcurrentSkipListMapinstance. (The keys and values themselves are not cloned.)- Overrides:
- clonein class- AbstractMap<K,- V> 
- Returns:
- a shallow copy of this map
- See Also:
 
- 
containsKeyReturnstrueif this map contains a mapping for the specified key.- Specified by:
- containsKeyin interface- Map<K,- V> 
- Overrides:
- containsKeyin class- AbstractMap<K,- V> 
- Parameters:
- key- key whose presence in this map is to be tested
- Returns:
- trueif this map contains a mapping for the specified key
- Throws:
- ClassCastException- if the specified key cannot be compared with the keys currently in the map
- NullPointerException- if the specified key is null
 
- 
getReturns the value to which the specified key is mapped, ornullif this map contains no mapping for the key.More formally, if this map contains a mapping from a key kto a valuevsuch thatkeycompares equal tokaccording to the map's ordering, then this method returnsv; otherwise it returnsnull. (There can be at most one such mapping.)- Specified by:
- getin interface- Map<K,- V> 
- Overrides:
- getin class- AbstractMap<K,- V> 
- Parameters:
- key- the key whose associated value is to be returned
- Returns:
- the value to which the specified key is mapped, or
         nullif this map contains no mapping for the key
- Throws:
- ClassCastException- if the specified key cannot be compared with the keys currently in the map
- NullPointerException- if the specified key is null
 
- 
getOrDefaultReturns the value to which the specified key is mapped, or the given defaultValue if this map contains no mapping for the key.- Specified by:
- getOrDefaultin interface- ConcurrentMap<K,- V> 
- Specified by:
- getOrDefaultin interface- Map<K,- V> 
- Parameters:
- key- the key
- defaultValue- the value to return if this map contains no mapping for the given key
- Returns:
- the mapping for the key, if present; else the defaultValue
- Throws:
- NullPointerException- if the specified key is null
- Since:
- 1.8
 
- 
putAssociates 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.- Specified by:
- putin interface- Map<K,- V> 
- Overrides:
- putin class- AbstractMap<K,- V> 
- Parameters:
- key- key with which the specified value is to be associated
- value- value to be associated with the specified key
- Returns:
- the previous value associated with the specified key, or
         nullif there was no mapping for the key
- Throws:
- ClassCastException- if the specified key cannot be compared with the keys currently in the map
- NullPointerException- if the specified key or value is null
 
- 
removeRemoves the mapping for the specified key from this map if present.- Specified by:
- removein interface- Map<K,- V> 
- Overrides:
- removein class- AbstractMap<K,- V> 
- Parameters:
- key- key for which mapping should be removed
- Returns:
- the previous value associated with the specified key, or
         nullif there was no mapping for the key
- Throws:
- ClassCastException- if the specified key cannot be compared with the keys currently in the map
- NullPointerException- if the specified key is null
 
- 
containsValueReturnstrueif this map maps one or more keys to the specified value. This operation requires time linear in the map size. Additionally, it is possible for the map to change during execution of this method, in which case the returned result may be inaccurate.- Specified by:
- containsValuein interface- Map<K,- V> 
- Overrides:
- containsValuein class- AbstractMap<K,- V> 
- Parameters:
- value- value whose presence in this map is to be tested
- Returns:
- trueif a mapping to- valueexists;- falseotherwise
- Throws:
- NullPointerException- if the specified value is null
 
- 
sizepublic int size()Returns the number of key-value mappings in this map. If the map contains more thanInteger.MAX_VALUEelements, returnsInteger.MAX_VALUE.
- 
isEmptypublic boolean isEmpty()Returnstrueif this map contains no key-value mappings.
- 
clearpublic void clear()Removes all of the mappings from this map.
- 
computeIfAbsentIf the specified key is not already associated with a value, attempts to compute its value using the given mapping function and enters it into this map unlessnull. The function is NOT guaranteed to be applied once atomically only if the value is not present.- Specified by:
- computeIfAbsentin interface- ConcurrentMap<K,- V> 
- Specified by:
- computeIfAbsentin interface- Map<K,- V> 
- Parameters:
- key- key with which the specified value is to be associated
- mappingFunction- the function to compute a value
- Returns:
- the current (existing or computed) value associated with the specified key, or null if the computed value is null
- Throws:
- NullPointerException- if the specified key is null or the mappingFunction is null
- Since:
- 1.8
 
- 
computeIfPresentIf the value for the specified key is present, attempts to compute a new mapping given the key and its current mapped value. The function is NOT guaranteed to be applied once atomically.- Specified by:
- computeIfPresentin interface- ConcurrentMap<K,- V> 
- Specified by:
- computeIfPresentin interface- Map<K,- V> 
- Parameters:
- key- key with which a value may be associated
- remappingFunction- the function to compute a value
- Returns:
- the new value associated with the specified key, or null if none
- Throws:
- NullPointerException- if the specified key is null or the remappingFunction is null
- Since:
- 1.8
 
- 
computeAttempts to compute a mapping for the specified key and its current mapped value (ornullif there is no current mapping). The function is NOT guaranteed to be applied once atomically.- Specified by:
- computein interface- ConcurrentMap<K,- V> 
- Specified by:
- computein interface- Map<K,- V> 
- Parameters:
- key- key with which the specified value is to be associated
- remappingFunction- the function to compute a value
- Returns:
- the new value associated with the specified key, or null if none
- Throws:
- NullPointerException- if the specified key is null or the remappingFunction is null
- Since:
- 1.8
 
- 
mergeIf the specified key is not already associated with a value, associates it with the given value. Otherwise, replaces the value with the results of the given remapping function, or removes ifnull. The function is NOT guaranteed to be applied once atomically.- Specified by:
- mergein interface- ConcurrentMap<K,- V> 
- Specified by:
- mergein interface- Map<K,- V> 
- Parameters:
- key- key with which the specified value is to be associated
- value- the value to use if absent
- remappingFunction- the function to recompute a value if present
- Returns:
- the new value associated with the specified key, or null if none
- Throws:
- NullPointerException- if the specified key or value is null or the remappingFunction is null
- Since:
- 1.8
 
- 
keySetReturns aNavigableSetview of the keys contained in this map.The set's iterator returns the keys in ascending order. The set's spliterator additionally reports Spliterator.CONCURRENT,Spliterator.NONNULL,Spliterator.SORTEDandSpliterator.ORDERED, with an encounter order that is ascending key order.The spliterator's comparator is nullif the map's comparator isnull. Otherwise, the spliterator's comparator is the same as or imposes the same total ordering as the map's comparator.The set is backed by the map, so changes to the map are reflected in the set, and vice-versa. The set supports element removal, which removes the corresponding mapping from the map, via the Iterator.remove,Set.remove,removeAll,retainAll, andclearoperations. It does not support theaddoraddAlloperations.The view's iterators and spliterators are weakly consistent. This method is equivalent to method navigableKeySet.
- 
valuesReturns aCollectionview of the values contained in this map.The collection's iterator returns the values in ascending order of the corresponding keys. The collections's spliterator additionally reports Spliterator.CONCURRENT,Spliterator.NONNULLandSpliterator.ORDERED, with an encounter order that is ascending order of the corresponding keys.The collection is backed by the map, so changes to the map are reflected in the collection, and vice-versa. The collection supports element removal, which removes the corresponding mapping from the map, via the Iterator.remove,Collection.remove,removeAll,retainAllandclearoperations. It does not support theaddoraddAlloperations.The view's iterators and spliterators are weakly consistent. 
- 
entrySetReturns aSetview of the mappings contained in this map.The set's iterator returns the entries in ascending key order. The set's spliterator additionally reports Spliterator.CONCURRENT,Spliterator.NONNULL,Spliterator.SORTEDandSpliterator.ORDERED, with an encounter order that is ascending key order.The set is backed by the map, so changes to the map are reflected in the set, and vice-versa. The set supports element removal, which removes the corresponding mapping from the map, via the Iterator.remove,Set.remove,removeAll,retainAllandclearoperations. It does not support theaddoraddAlloperations.The view's iterators and spliterators are weakly consistent. The Map.Entryelements traversed by theiteratororspliteratordo not support thesetValueoperation.
- 
descendingMapDescription copied from interface:ConcurrentNavigableMapReturns a reverse order view of the mappings contained in this map. The descending map is backed by this map, so changes to the map are reflected in the descending map, and vice-versa.The returned map has an ordering equivalent to Collections.reverseOrder(comparator()). The expressionm.descendingMap().descendingMap()returns a view ofmessentially equivalent tom.- Specified by:
- descendingMapin interface- ConcurrentNavigableMap<K,- V> 
- Specified by:
- descendingMapin interface- NavigableMap<K,- V> 
- Returns:
- a reverse order view of this map
 
- 
descendingKeySetDescription copied from interface:ConcurrentNavigableMapReturns a reverse orderNavigableSetview of the keys contained in this map. The set's iterator returns the keys in descending order. The set is backed by the map, so changes to the map are reflected in the set, and vice-versa. The set supports element removal, which removes the corresponding mapping from the map, via theIterator.remove,Set.remove,removeAll,retainAll, andclearoperations. It does not support theaddoraddAlloperations.The view's iterators and spliterators are weakly consistent. - Specified by:
- descendingKeySetin interface- ConcurrentNavigableMap<K,- V> 
- Specified by:
- descendingKeySetin interface- NavigableMap<K,- V> 
- Returns:
- a reverse order navigable set view of the keys in this map
 
- 
equalsCompares the specified object with this map for equality. Returnstrueif the given object is also a map and the two maps represent the same mappings. More formally, two mapsm1andm2represent the same mappings ifm1.entrySet().equals(m2.entrySet()). This operation may return misleading results if either map is concurrently modified during execution of this method.
- 
putIfAbsentIf the specified key is not already associated with a value, associates it with the given value. This is equivalent to, for thismap:
 except that the action is performed atomically.if (!map.containsKey(key)) return map.put(key, value); else return map.get(key);- Specified by:
- putIfAbsentin interface- ConcurrentMap<K,- V> 
- Specified by:
- putIfAbsentin interface- Map<K,- V> 
- Parameters:
- key- key with which the specified value is to be associated
- value- value to be associated with the specified key
- Returns:
- the previous value associated with the specified key,
         or nullif there was no mapping for the key
- Throws:
- ClassCastException- if the specified key cannot be compared with the keys currently in the map
- NullPointerException- if the specified key or value is null
 
- 
removeRemoves the entry for a key only if currently mapped to a given value. This is equivalent to, for thismap:
 except that the action is performed atomically.if (map.containsKey(key) && Objects.equals(map.get(key), value)) { map.remove(key); return true; } else { return false; }- Specified by:
- removein interface- ConcurrentMap<K,- V> 
- Specified by:
- removein interface- Map<K,- V> 
- Parameters:
- key- key with which the specified value is associated
- value- value expected to be associated with the specified key
- Returns:
- trueif the value was removed
- Throws:
- ClassCastException- if the specified key cannot be compared with the keys currently in the map
- NullPointerException- if the specified key is null
 
- 
replaceReplaces the entry for a key only if currently mapped to a given value. This is equivalent to, for thismap:
 except that the action is performed atomically.if (map.containsKey(key) && Objects.equals(map.get(key), oldValue)) { map.put(key, newValue); return true; } else { return false; }- Specified by:
- replacein interface- ConcurrentMap<K,- V> 
- Specified by:
- replacein interface- Map<K,- V> 
- Parameters:
- key- key with which the specified value is associated
- oldValue- value expected to be associated with the specified key
- newValue- value to be associated with the specified key
- Returns:
- trueif the value was replaced
- Throws:
- ClassCastException- if the specified key cannot be compared with the keys currently in the map
- NullPointerException- if any of the arguments are null
 
- 
replaceReplaces the entry for a key only if currently mapped to some value. This is equivalent to, for thismap:
 except that the action is performed atomically.if (map.containsKey(key)) return map.put(key, value); else return null;- Specified by:
- replacein interface- ConcurrentMap<K,- V> 
- Specified by:
- replacein interface- Map<K,- V> 
- Parameters:
- key- key with which the specified value is associated
- value- value to be associated with the specified key
- Returns:
- the previous value associated with the specified key,
         or nullif there was no mapping for the key
- Throws:
- ClassCastException- if the specified key cannot be compared with the keys currently in the map
- NullPointerException- if the specified key or value is null
 
- 
comparatorDescription copied from interface:SortedMapReturns the comparator used to order the keys in this map, ornullif this map uses the natural ordering of its keys.- Specified by:
- comparatorin interface- SortedMap<K,- V> 
- Returns:
- the comparator used to order the keys in this map,
         or nullif this map uses the natural ordering of its keys
 
- 
firstKeyDescription copied from interface:SortedMapReturns the first (lowest) key currently in this map.- Specified by:
- firstKeyin interface- SortedMap<K,- V> 
- Returns:
- the first (lowest) key currently in this map
- Throws:
- NoSuchElementException- if this map is empty
 
- 
lastKeyDescription copied from interface:SortedMapReturns the last (highest) key currently in this map.- Specified by:
- lastKeyin interface- SortedMap<K,- V> 
- Returns:
- the last (highest) key currently in this map
- Throws:
- NoSuchElementException- if this map is empty
 
- 
putFirstThrowsUnsupportedOperationException. The encounter order induced by this map's comparison method determines the position of mappings, so explicit positioning is not supported.- Specified by:
- putFirstin interface- SequencedMap<K,- V> 
- Specified by:
- putFirstin interface- SortedMap<K,- V> 
- Parameters:
- k- the key
- v- the value
- Returns:
- the value previously associated with k, or null if none
- Throws:
- UnsupportedOperationException- always
- Since:
- 21
 
- 
putLastThrowsUnsupportedOperationException. The encounter order induced by this map's comparison method determines the position of mappings, so explicit positioning is not supported.- Specified by:
- putLastin interface- SequencedMap<K,- V> 
- Specified by:
- putLastin interface- SortedMap<K,- V> 
- Parameters:
- k- the key
- v- the value
- Returns:
- the value previously associated with k, or null if none
- Throws:
- UnsupportedOperationException- always
- Since:
- 21
 
- 
subMappublic ConcurrentNavigableMap<K,V> subMap(K fromKey, boolean fromInclusive, K toKey, boolean toInclusive) Description copied from interface:NavigableMapReturns a view of the portion of this map whose keys range fromfromKeytotoKey. IffromKeyandtoKeyare equal, the returned map is empty unlessfromInclusiveandtoInclusiveare both true. The returned map is backed by this map, so changes in the returned map are reflected in this map, and vice-versa. The returned map supports all optional map operations that this map supports.The returned map will throw an IllegalArgumentExceptionon an attempt to insert a key outside of its range, or to construct a submap either of whose endpoints lie outside its range.- Specified by:
- subMapin interface- ConcurrentNavigableMap<K,- V> 
- Specified by:
- subMapin interface- NavigableMap<K,- V> 
- Parameters:
- fromKey- low endpoint of the keys in the returned map
- fromInclusive-- trueif the low endpoint is to be included in the returned view
- toKey- high endpoint of the keys in the returned map
- toInclusive-- trueif the high endpoint is to be included in the returned view
- Returns:
- a view of the portion of this map whose keys range from
         fromKeytotoKey
- Throws:
- ClassCastException- if- fromKeyand- toKeycannot be compared to one another using this map's comparator (or, if the map has no comparator, using natural ordering). Implementations may, but are not required to, throw this exception if- fromKeyor- toKeycannot be compared to keys currently in the map.
- NullPointerException- if- fromKeyor- toKeyis null
- IllegalArgumentException- if- fromKeyis greater than- toKey; or if this map itself has a restricted range, and- fromKeyor- toKeylies outside the bounds of the range
 
- 
headMapDescription copied from interface:NavigableMapReturns a view of the portion of this map whose keys are less than (or equal to, ifinclusiveis true)toKey. The returned map is backed by this map, so changes in the returned map are reflected in this map, and vice-versa. The returned map supports all optional map operations that this map supports.The returned map will throw an IllegalArgumentExceptionon an attempt to insert a key outside its range.- Specified by:
- headMapin interface- ConcurrentNavigableMap<K,- V> 
- Specified by:
- headMapin interface- NavigableMap<K,- V> 
- Parameters:
- toKey- high endpoint of the keys in the returned map
- inclusive-- trueif the high endpoint is to be included in the returned view
- Returns:
- a view of the portion of this map whose keys are less than
         (or equal to, if inclusiveis true)toKey
- Throws:
- ClassCastException- if- toKeyis not compatible with this map's comparator (or, if the map has no comparator, if- toKeydoes not implement- Comparable). Implementations may, but are not required to, throw this exception if- toKeycannot be compared to keys currently in the map.
- NullPointerException- if- toKeyis null
- IllegalArgumentException- if this map itself has a restricted range, and- toKeylies outside the bounds of the range
 
- 
tailMapDescription copied from interface:NavigableMapReturns a view of the portion of this map whose keys are greater than (or equal to, ifinclusiveis true)fromKey. The returned map is backed by this map, so changes in the returned map are reflected in this map, and vice-versa. The returned map supports all optional map operations that this map supports.The returned map will throw an IllegalArgumentExceptionon an attempt to insert a key outside its range.- Specified by:
- tailMapin interface- ConcurrentNavigableMap<K,- V> 
- Specified by:
- tailMapin interface- NavigableMap<K,- V> 
- Parameters:
- fromKey- low endpoint of the keys in the returned map
- inclusive-- trueif the low endpoint is to be included in the returned view
- Returns:
- a view of the portion of this map whose keys are greater than
         (or equal to, if inclusiveis true)fromKey
- Throws:
- ClassCastException- if- fromKeyis not compatible with this map's comparator (or, if the map has no comparator, if- fromKeydoes not implement- Comparable). Implementations may, but are not required to, throw this exception if- fromKeycannot be compared to keys currently in the map.
- NullPointerException- if- fromKeyis null
- IllegalArgumentException- if this map itself has a restricted range, and- fromKeylies outside the bounds of the range
 
- 
subMapDescription copied from interface:NavigableMapReturns a view of the portion of this map whose keys range fromfromKey, inclusive, totoKey, exclusive. (IffromKeyandtoKeyare equal, the returned map is empty.) The returned map is backed by this map, so changes in the returned map are reflected in this map, and vice-versa. The returned map supports all optional map operations that this map supports.The returned map will throw an IllegalArgumentExceptionon an attempt to insert a key outside its range.Equivalent to subMap(fromKey, true, toKey, false).- Specified by:
- subMapin interface- ConcurrentNavigableMap<K,- V> 
- Specified by:
- subMapin interface- NavigableMap<K,- V> 
- Specified by:
- subMapin interface- SortedMap<K,- V> 
- Parameters:
- fromKey- low endpoint (inclusive) of the keys in the returned map
- toKey- high endpoint (exclusive) of the keys in the returned map
- Returns:
- a view of the portion of this map whose keys range from
         fromKey, inclusive, totoKey, exclusive
- Throws:
- ClassCastException- if- fromKeyand- toKeycannot be compared to one another using this map's comparator (or, if the map has no comparator, using natural ordering). Implementations may, but are not required to, throw this exception if- fromKeyor- toKeycannot be compared to keys currently in the map.
- NullPointerException- if- fromKeyor- toKeyis null
- IllegalArgumentException- if- fromKeyis greater than- toKey; or if this map itself has a restricted range, and- fromKeyor- toKeylies outside the bounds of the range
 
- 
headMapDescription copied from interface:NavigableMapReturns a view of the portion of this map whose keys are strictly less thantoKey. The returned map is backed by this map, so changes in the returned map are reflected in this map, and vice-versa. The returned map supports all optional map operations that this map supports.The returned map will throw an IllegalArgumentExceptionon an attempt to insert a key outside its range.Equivalent to headMap(toKey, false).- Specified by:
- headMapin interface- ConcurrentNavigableMap<K,- V> 
- Specified by:
- headMapin interface- NavigableMap<K,- V> 
- Specified by:
- headMapin interface- SortedMap<K,- V> 
- Parameters:
- toKey- high endpoint (exclusive) of the keys in the returned map
- Returns:
- a view of the portion of this map whose keys are strictly
         less than toKey
- Throws:
- ClassCastException- if- toKeyis not compatible with this map's comparator (or, if the map has no comparator, if- toKeydoes not implement- Comparable). Implementations may, but are not required to, throw this exception if- toKeycannot be compared to keys currently in the map.
- NullPointerException- if- toKeyis null
- IllegalArgumentException- if this map itself has a restricted range, and- toKeylies outside the bounds of the range
 
- 
tailMapDescription copied from interface:NavigableMapReturns a view of the portion of this map whose keys are greater than or equal tofromKey. The returned map is backed by this map, so changes in the returned map are reflected in this map, and vice-versa. The returned map supports all optional map operations that this map supports.The returned map will throw an IllegalArgumentExceptionon an attempt to insert a key outside its range.Equivalent to tailMap(fromKey, true).- Specified by:
- tailMapin interface- ConcurrentNavigableMap<K,- V> 
- Specified by:
- tailMapin interface- NavigableMap<K,- V> 
- Specified by:
- tailMapin interface- SortedMap<K,- V> 
- Parameters:
- fromKey- low endpoint (inclusive) of the keys in the returned map
- Returns:
- a view of the portion of this map whose keys are greater
         than or equal to fromKey
- Throws:
- ClassCastException- if- fromKeyis not compatible with this map's comparator (or, if the map has no comparator, if- fromKeydoes not implement- Comparable). Implementations may, but are not required to, throw this exception if- fromKeycannot be compared to keys currently in the map.
- NullPointerException- if- fromKeyis null
- IllegalArgumentException- if this map itself has a restricted range, and- fromKeylies outside the bounds of the range
 
- 
lowerEntryReturns a key-value mapping associated with the greatest key strictly less than the given key, ornullif there is no such key. The returned entry does not support theEntry.setValuemethod.- Specified by:
- lowerEntryin interface- NavigableMap<K,- V> 
- Parameters:
- key- the key
- Returns:
- an entry with the greatest key less than key, ornullif there is no such key
- Throws:
- ClassCastException- if the specified key cannot be compared with the keys currently in the map
- NullPointerException- if the specified key is null
 
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lowerKeyDescription copied from interface:NavigableMapReturns the greatest key strictly less than the given key, ornullif there is no such key.- Specified by:
- lowerKeyin interface- NavigableMap<K,- V> 
- Parameters:
- key- the key
- Returns:
- the greatest key less than key, ornullif there is no such key
- Throws:
- ClassCastException- if the specified key cannot be compared with the keys currently in the map
- NullPointerException- if the specified key is null
 
- 
floorEntryReturns a key-value mapping associated with the greatest key less than or equal to the given key, ornullif there is no such key. The returned entry does not support theEntry.setValuemethod.- Specified by:
- floorEntryin interface- NavigableMap<K,- V> 
- Parameters:
- key- the key
- Returns:
- an entry with the greatest key less than or equal to
         key, ornullif there is no such key
- Throws:
- ClassCastException- if the specified key cannot be compared with the keys currently in the map
- NullPointerException- if the specified key is null
 
- 
floorKeyDescription copied from interface:NavigableMapReturns the greatest key less than or equal to the given key, ornullif there is no such key.- Specified by:
- floorKeyin interface- NavigableMap<K,- V> 
- Parameters:
- key- the key
- Returns:
- the greatest key less than or equal to key, ornullif there is no such key
- Throws:
- ClassCastException- if the specified key cannot be compared with the keys currently in the map
- NullPointerException- if the specified key is null
 
- 
ceilingEntryReturns a key-value mapping associated with the least key greater than or equal to the given key, ornullif there is no such entry. The returned entry does not support theEntry.setValuemethod.- Specified by:
- ceilingEntryin interface- NavigableMap<K,- V> 
- Parameters:
- key- the key
- Returns:
- an entry with the least key greater than or equal to
         key, ornullif there is no such key
- Throws:
- ClassCastException- if the specified key cannot be compared with the keys currently in the map
- NullPointerException- if the specified key is null
 
- 
ceilingKeyDescription copied from interface:NavigableMapReturns the least key greater than or equal to the given key, ornullif there is no such key.- Specified by:
- ceilingKeyin interface- NavigableMap<K,- V> 
- Parameters:
- key- the key
- Returns:
- the least key greater than or equal to key, ornullif there is no such key
- Throws:
- ClassCastException- if the specified key cannot be compared with the keys currently in the map
- NullPointerException- if the specified key is null
 
- 
higherEntryReturns a key-value mapping associated with the least key strictly greater than the given key, ornullif there is no such key. The returned entry does not support theEntry.setValuemethod.- Specified by:
- higherEntryin interface- NavigableMap<K,- V> 
- Parameters:
- key- the key
- Returns:
- an entry with the least key greater than key, ornullif there is no such key
- Throws:
- ClassCastException- if the specified key cannot be compared with the keys currently in the map
- NullPointerException- if the specified key is null
 
- 
higherKeyDescription copied from interface:NavigableMapReturns the least key strictly greater than the given key, ornullif there is no such key.- Specified by:
- higherKeyin interface- NavigableMap<K,- V> 
- Parameters:
- key- the key
- Returns:
- the least key greater than key, ornullif there is no such key
- Throws:
- ClassCastException- if the specified key cannot be compared with the keys currently in the map
- NullPointerException- if the specified key is null
 
- 
firstEntryReturns a key-value mapping associated with the least key in this map, ornullif the map is empty. The returned entry does not support theEntry.setValuemethod.- Specified by:
- firstEntryin interface- NavigableMap<K,- V> 
- Specified by:
- firstEntryin interface- SequencedMap<K,- V> 
- Returns:
- an entry with the least key,
         or nullif this map is empty
 
- 
lastEntryReturns a key-value mapping associated with the greatest key in this map, ornullif the map is empty. The returned entry does not support theEntry.setValuemethod.- Specified by:
- lastEntryin interface- NavigableMap<K,- V> 
- Specified by:
- lastEntryin interface- SequencedMap<K,- V> 
- Returns:
- an entry with the greatest key,
         or nullif this map is empty
 
- 
pollFirstEntryRemoves and returns a key-value mapping associated with the least key in this map, ornullif the map is empty. The returned entry does not support theEntry.setValuemethod.- Specified by:
- pollFirstEntryin interface- NavigableMap<K,- V> 
- Specified by:
- pollFirstEntryin interface- SequencedMap<K,- V> 
- Returns:
- the removed first entry of this map,
         or nullif this map is empty
 
- 
pollLastEntryRemoves and returns a key-value mapping associated with the greatest key in this map, ornullif the map is empty. The returned entry does not support theEntry.setValuemethod.- Specified by:
- pollLastEntryin interface- NavigableMap<K,- V> 
- Specified by:
- pollLastEntryin interface- SequencedMap<K,- V> 
- Returns:
- the removed last entry of this map,
         or nullif this map is empty
 
 
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