- java.lang.Object
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- java.util.AbstractMap<K,V>
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- java.util.concurrent.ConcurrentSkipListMap<K,V>
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- Type Parameters:
K- the type of keys maintained by this mapV- the type of mapped values
- All Implemented Interfaces:
Serializable,Cloneable,ConcurrentMap<K,V>,ConcurrentNavigableMap<K,V>,Map<K,V>,NavigableMap<K,V>,SortedMap<K,V>
public class ConcurrentSkipListMap<K,V> extends AbstractMap<K,V> implements ConcurrentNavigableMap<K,V>, Cloneable, Serializable
A scalable concurrentConcurrentNavigableMapimplementation. The map is sorted according to the natural ordering of its keys, or by aComparatorprovided 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,putandremoveoperations 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.Entrypairs returned by methods in this class and its views represent snapshots of mappings at the time they were produced. They do not support theEntry.setValuemethod. (Note however that it is possible to change mappings in the associated map usingput,putIfAbsent, orreplace, depending on exactly which effect you need.)Beware that bulk operations
putAll,equals,toArray,containsValue, andclearare not guaranteed to be performed atomically. For example, an iterator operating concurrently with aputAlloperation might view only some of the added elements.This class and its views and iterators implement all of the optional methods of the
MapandIteratorinterfaces. Like most other concurrent collections, this class does not permit the use ofnullkeys 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:
- Serialized Form
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Nested Class Summary
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Nested classes/interfaces declared in class java.util.AbstractMap
AbstractMap.SimpleEntry<K,V>, AbstractMap.SimpleImmutableEntry<K,V>
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Constructor Summary
Constructors Constructor Description ConcurrentSkipListMap()Constructs 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.
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Method Summary
All Methods Instance Methods Concrete Methods Modifier and Type Method Description Map.Entry<K,V>ceilingEntry(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.KceilingKey(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.ConcurrentSkipListMap<K,V>clone()Returns a shallow copy of thisConcurrentSkipListMapinstance.Vcompute(K key, BiFunction<? super K,? super V,? extends V> remappingFunction)Attempts to compute a mapping for the specified key and its current mapped value (ornullif there is no current mapping).VcomputeIfAbsent(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.VcomputeIfPresent(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.Set<Map.Entry<K,V>>entrySet()Returns aSetview of the mappings contained in this map.booleanequals(Object o)Compares the specified object with this map for equality.Map.Entry<K,V>firstEntry()Returns a key-value mapping associated with the least key in this map, ornullif the map is empty.KfirstKey()Returns the first (lowest) key currently in this map.Map.Entry<K,V>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.KfloorKey(K key)Returns the greatest key less than or equal to the given key, ornullif there is no such key.Vget(Object key)Returns the value to which the specified key is mapped, ornullif this map contains no mapping for the key.VgetOrDefault(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.ConcurrentNavigableMap<K,V>headMap(K toKey)Returns a view of the portion of this map whose keys are strictly less thantoKey.ConcurrentNavigableMap<K,V>headMap(K toKey, boolean inclusive)Returns a view of the portion of this map whose keys are less than (or equal to, ifinclusiveis true)toKey.Map.Entry<K,V>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.KhigherKey(K key)Returns the least key strictly greater than the given key, ornullif there is no such key.NavigableSet<K>keySet()Returns aNavigableSetview of the keys contained in this map.Map.Entry<K,V>lastEntry()Returns a key-value mapping associated with the greatest key in this map, ornullif the map is empty.KlastKey()Returns the last (highest) key currently in this map.Map.Entry<K,V>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.KlowerKey(K key)Returns the greatest key strictly less than the given key, ornullif there is no such key.Vmerge(K key, V value, BiFunction<? super V,? super V,? extends V> remappingFunction)If the specified key is not already associated with a value, associates it with the given value.Map.Entry<K,V>pollFirstEntry()Removes and returns a key-value mapping associated with the least key in this map, ornullif the map is empty.Map.Entry<K,V>pollLastEntry()Removes and returns a key-value mapping associated with the greatest key in this map, ornullif the map is empty.Vput(K key, V value)Associates the specified value with the specified key in this map.VputIfAbsent(K key, V value)If the specified key is not already associated with a value, associates it with the given value.Vremove(Object key)Removes the mapping for the specified key from this map if present.booleanremove(Object key, Object value)Removes the entry for a key only if currently mapped to a given value.Vreplace(K key, V value)Replaces the entry for a key only if currently mapped to some value.booleanreplace(K key, V oldValue, V newValue)Replaces the entry for a key only if currently mapped to a given value.ConcurrentNavigableMap<K,V>subMap(K fromKey, boolean fromInclusive, K toKey, boolean toInclusive)Returns a view of the portion of this map whose keys range fromfromKeytotoKey.ConcurrentNavigableMap<K,V>subMap(K fromKey, K toKey)Returns a view of the portion of this map whose keys range fromfromKey, inclusive, totoKey, exclusive.ConcurrentNavigableMap<K,V>tailMap(K fromKey)Returns a view of the portion of this map whose keys are greater than or equal tofromKey.ConcurrentNavigableMap<K,V>tailMap(K fromKey, boolean inclusive)Returns a view of the portion of this map whose keys are greater than (or equal to, ifinclusiveis true)fromKey.Collection<V>values()Returns aCollectionview of the values contained in this map.-
Methods declared in interface java.util.concurrent.ConcurrentMap
forEach, replaceAll
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Methods declared in interface java.util.concurrent.ConcurrentNavigableMap
descendingKeySet, descendingMap, navigableKeySet
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Methods declared in interface java.util.SortedMap
comparator
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Constructor Detail
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ConcurrentSkipListMap
public ConcurrentSkipListMap()
Constructs a new, empty map, sorted according to the natural ordering of the keys.
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ConcurrentSkipListMap
public ConcurrentSkipListMap(Comparator<? super K> comparator)
Constructs a new, empty map, sorted according to the specified comparator.- Parameters:
comparator- the comparator that will be used to order this map. Ifnull, the natural ordering of the keys will be used.
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ConcurrentSkipListMap
public 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.- Parameters:
m- the map whose mappings are to be placed in this map- Throws:
ClassCastException- if the keys inmare notComparable, or are not mutually comparableNullPointerException- if the specified map or any of its keys or values are null
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ConcurrentSkipListMap
public ConcurrentSkipListMap(SortedMap<K,? extends V> m)
Constructs 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
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Method Detail
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clone
public ConcurrentSkipListMap<K,V> clone()
Returns a shallow copy of thisConcurrentSkipListMapinstance. (The keys and values themselves are not cloned.)- Overrides:
clonein classAbstractMap<K,V>- Returns:
- a shallow copy of this map
- See Also:
Cloneable
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containsKey
public boolean containsKey(Object key)
Returnstrueif this map contains a mapping for the specified key.- Specified by:
containsKeyin interfaceMap<K,V>- Overrides:
containsKeyin classAbstractMap<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 mapNullPointerException- if the specified key is null
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get
public V get(Object key)
Returns 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 interfaceMap<K,V>- Overrides:
getin classAbstractMap<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 mapNullPointerException- if the specified key is null
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getOrDefault
public V 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.- Specified by:
getOrDefaultin interfaceConcurrentMap<K,V>- Specified by:
getOrDefaultin interfaceMap<K,V>- Parameters:
key- the keydefaultValue- 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
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put
public 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.- Specified by:
putin interfaceMap<K,V>- Overrides:
putin classAbstractMap<K,V>- Parameters:
key- key with which the specified value is to be associatedvalue- 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 mapNullPointerException- if the specified key or value is null
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remove
public V remove(Object key)
Removes the mapping for the specified key from this map if present.- Specified by:
removein interfaceMap<K,V>- Overrides:
removein classAbstractMap<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 mapNullPointerException- if the specified key is null
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containsValue
public boolean containsValue(Object value)
Returnstrueif 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 interfaceMap<K,V>- Overrides:
containsValuein classAbstractMap<K,V>- Parameters:
value- value whose presence in this map is to be tested- Returns:
trueif a mapping tovalueexists;falseotherwise- Throws:
NullPointerException- if the specified value is null
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clear
public void clear()
Removes all of the mappings from this map.
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computeIfAbsent
public V 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. The function is NOT guaranteed to be applied once atomically only if the value is not present.- Specified by:
computeIfAbsentin interfaceConcurrentMap<K,V>- Specified by:
computeIfAbsentin interfaceMap<K,V>- Parameters:
key- key with which the specified value is to be associatedmappingFunction- 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
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computeIfPresent
public V 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. The function is NOT guaranteed to be applied once atomically.- Specified by:
computeIfPresentin interfaceConcurrentMap<K,V>- Specified by:
computeIfPresentin interfaceMap<K,V>- Parameters:
key- key with which a value may be associatedremappingFunction- 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
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compute
public V compute(K key, BiFunction<? super K,? super V,? extends V> remappingFunction)
Attempts 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 interfaceConcurrentMap<K,V>- Specified by:
computein interfaceMap<K,V>- Parameters:
key- key with which the specified value is to be associatedremappingFunction- 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
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merge
public V merge(K key, V value, BiFunction<? super V,? super V,? extends V> remappingFunction)
If 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 interfaceConcurrentMap<K,V>- Specified by:
mergein interfaceMap<K,V>- Parameters:
key- key with which the specified value is to be associatedvalue- the value to use if absentremappingFunction- 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
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keySet
public NavigableSet<K> keySet()
Returns 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.
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values
public Collection<V> values()
Returns 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.
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entrySet
public Set<Map.Entry<K,V>> entrySet()
Returns 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.
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equals
public boolean equals(Object o)
Compares 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.- Specified by:
equalsin interfaceMap<K,V>- Overrides:
equalsin classAbstractMap<K,V>- Parameters:
o- object to be compared for equality with this map- Returns:
trueif the specified object is equal to this map- See Also:
Object.hashCode(),HashMap
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putIfAbsent
public V putIfAbsent(K key, V value)
If 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 interfaceConcurrentMap<K,V>- Specified by:
putIfAbsentin interfaceMap<K,V>- Parameters:
key- key with which the specified value is to be associatedvalue- 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 mapNullPointerException- if the specified key or value is null
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remove
public boolean remove(Object key, Object value)
Removes 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 interfaceConcurrentMap<K,V>- Specified by:
removein interfaceMap<K,V>- Parameters:
key- key with which the specified value is associatedvalue- 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 mapNullPointerException- if the specified key is null
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replace
public 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, 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 interfaceConcurrentMap<K,V>- Specified by:
replacein interfaceMap<K,V>- Parameters:
key- key with which the specified value is associatedoldValue- value expected to be associated with the specified keynewValue- 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 mapNullPointerException- if any of the arguments are null
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replace
public V replace(K key, V value)
Replaces 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 interfaceConcurrentMap<K,V>- Specified by:
replacein interfaceMap<K,V>- Parameters:
key- key with which the specified value is associatedvalue- 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 mapNullPointerException- if the specified key or value is null
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firstKey
public K firstKey()
Description copied from interface:SortedMapReturns the first (lowest) key currently in this map.- Specified by:
firstKeyin interfaceSortedMap<K,V>- Returns:
- the first (lowest) key currently in this map
- Throws:
NoSuchElementException- if this map is empty
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lastKey
public K lastKey()
Description copied from interface:SortedMapReturns the last (highest) key currently in this map.- Specified by:
lastKeyin interfaceSortedMap<K,V>- Returns:
- the last (highest) key currently in this map
- Throws:
NoSuchElementException- if this map is empty
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subMap
public 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 interfaceConcurrentNavigableMap<K,V>- Specified by:
subMapin interfaceNavigableMap<K,V>- Parameters:
fromKey- low endpoint of the keys in the returned mapfromInclusive-trueif the low endpoint is to be included in the returned viewtoKey- high endpoint of the keys in the returned maptoInclusive-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- iffromKeyandtoKeycannot 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 iffromKeyortoKeycannot be compared to keys currently in the map.NullPointerException- iffromKeyortoKeyis nullIllegalArgumentException- iffromKeyis greater thantoKey; or if this map itself has a restricted range, andfromKeyortoKeylies outside the bounds of the range
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headMap
public ConcurrentNavigableMap<K,V> headMap(K toKey, boolean inclusive)
Description 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 interfaceConcurrentNavigableMap<K,V>- Specified by:
headMapin interfaceNavigableMap<K,V>- Parameters:
toKey- high endpoint of the keys in the returned mapinclusive-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- iftoKeyis not compatible with this map's comparator (or, if the map has no comparator, iftoKeydoes not implementComparable). Implementations may, but are not required to, throw this exception iftoKeycannot be compared to keys currently in the map.NullPointerException- iftoKeyis nullIllegalArgumentException- if this map itself has a restricted range, andtoKeylies outside the bounds of the range
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tailMap
public ConcurrentNavigableMap<K,V> tailMap(K fromKey, boolean inclusive)
Description 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 interfaceConcurrentNavigableMap<K,V>- Specified by:
tailMapin interfaceNavigableMap<K,V>- Parameters:
fromKey- low endpoint of the keys in the returned mapinclusive-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- iffromKeyis not compatible with this map's comparator (or, if the map has no comparator, iffromKeydoes not implementComparable). Implementations may, but are not required to, throw this exception iffromKeycannot be compared to keys currently in the map.NullPointerException- iffromKeyis nullIllegalArgumentException- if this map itself has a restricted range, andfromKeylies outside the bounds of the range
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subMap
public ConcurrentNavigableMap<K,V> subMap(K fromKey, K toKey)
Description 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 interfaceConcurrentNavigableMap<K,V>- Specified by:
subMapin interfaceNavigableMap<K,V>- Specified by:
subMapin interfaceSortedMap<K,V>- Parameters:
fromKey- low endpoint (inclusive) of the keys in the returned maptoKey- 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- iffromKeyandtoKeycannot 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 iffromKeyortoKeycannot be compared to keys currently in the map.NullPointerException- iffromKeyortoKeyis nullIllegalArgumentException- iffromKeyis greater thantoKey; or if this map itself has a restricted range, andfromKeyortoKeylies outside the bounds of the range
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headMap
public ConcurrentNavigableMap<K,V> headMap(K toKey)
Description 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 interfaceConcurrentNavigableMap<K,V>- Specified by:
headMapin interfaceNavigableMap<K,V>- Specified by:
headMapin interfaceSortedMap<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- iftoKeyis not compatible with this map's comparator (or, if the map has no comparator, iftoKeydoes not implementComparable). Implementations may, but are not required to, throw this exception iftoKeycannot be compared to keys currently in the map.NullPointerException- iftoKeyis nullIllegalArgumentException- if this map itself has a restricted range, andtoKeylies outside the bounds of the range
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tailMap
public ConcurrentNavigableMap<K,V> tailMap(K fromKey)
Description 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 interfaceConcurrentNavigableMap<K,V>- Specified by:
tailMapin interfaceNavigableMap<K,V>- Specified by:
tailMapin interfaceSortedMap<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- iffromKeyis not compatible with this map's comparator (or, if the map has no comparator, iffromKeydoes not implementComparable). Implementations may, but are not required to, throw this exception iffromKeycannot be compared to keys currently in the map.NullPointerException- iffromKeyis nullIllegalArgumentException- if this map itself has a restricted range, andfromKeylies outside the bounds of the range
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lowerEntry
public Map.Entry<K,V> 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. The returned entry does not support theEntry.setValuemethod.- Specified by:
lowerEntryin interfaceNavigableMap<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 mapNullPointerException- if the specified key is null
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lowerKey
public K lowerKey(K key)
Description copied from interface:NavigableMapReturns the greatest key strictly less than the given key, ornullif there is no such key.- Specified by:
lowerKeyin interfaceNavigableMap<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 mapNullPointerException- if the specified key is null
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floorEntry
public Map.Entry<K,V> 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. The returned entry does not support theEntry.setValuemethod.- Specified by:
floorEntryin interfaceNavigableMap<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 mapNullPointerException- if the specified key is null
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floorKey
public K floorKey(K key)
Description copied from interface:NavigableMapReturns the greatest key less than or equal to the given key, ornullif there is no such key.- Specified by:
floorKeyin interfaceNavigableMap<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 mapNullPointerException- if the specified key is null
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ceilingEntry
public Map.Entry<K,V> ceilingEntry(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. The returned entry does not support theEntry.setValuemethod.- Specified by:
ceilingEntryin interfaceNavigableMap<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 mapNullPointerException- if the specified key is null
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ceilingKey
public K ceilingKey(K key)
Description copied from interface:NavigableMapReturns the least key greater than or equal to the given key, ornullif there is no such key.- Specified by:
ceilingKeyin interfaceNavigableMap<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 mapNullPointerException- if the specified key is null
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higherEntry
public Map.Entry<K,V> 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. The returned entry does not support theEntry.setValuemethod.- Specified by:
higherEntryin interfaceNavigableMap<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 mapNullPointerException- if the specified key is null
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higherKey
public K higherKey(K key)
Description copied from interface:NavigableMapReturns the least key strictly greater than the given key, ornullif there is no such key.- Specified by:
higherKeyin interfaceNavigableMap<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 mapNullPointerException- if the specified key is null
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firstEntry
public Map.Entry<K,V> firstEntry()
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:
firstEntryin interfaceNavigableMap<K,V>- Returns:
- an entry with the least key,
or
nullif this map is empty
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lastEntry
public Map.Entry<K,V> lastEntry()
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:
lastEntryin interfaceNavigableMap<K,V>- Returns:
- an entry with the greatest key,
or
nullif this map is empty
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pollFirstEntry
public Map.Entry<K,V> pollFirstEntry()
Removes 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 interfaceNavigableMap<K,V>- Returns:
- the removed first entry of this map,
or
nullif this map is empty
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pollLastEntry
public Map.Entry<K,V> pollLastEntry()
Removes 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 interfaceNavigableMap<K,V>- Returns:
- the removed last entry of this map,
or
nullif this map is empty
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