Class ConcurrentSkipListMap<K,V>
- java.lang.Object
-
- java.util.AbstractMap<K,V>
-
- java.util.concurrent.ConcurrentSkipListMap<K,V>
- 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>
,SortedMap<K,V>
public class ConcurrentSkipListMap<K,V> extends AbstractMap<K,V> implements ConcurrentNavigableMap<K,V>, Cloneable, Serializable
A scalable concurrent 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:
- Serialized Form
Nested Class Summary
Nested classes/interfaces declared in class java.util.AbstractMap
AbstractMap.SimpleEntry<K,V>, AbstractMap.SimpleImmutableEntry<K,V>
Nested classes/interfaces declared in interface java.util.Map
Map.Entry<K,V>
Constructor Summary
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. |
Method Summary
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, or |
K | ceilingKey(K key) | Returns the least key greater than or equal to the given key, or |
void | clear() | Removes all of the mappings from this map. |
ConcurrentSkipListMap<K,V> | clone() | Returns a shallow copy of this |
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 (or |
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 unless |
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. |
boolean | containsKey(Object key) | Returns |
boolean | containsValue(Object value) | Returns |
Set<Map.Entry<K,V>> | entrySet() | Returns a |
boolean | equals(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, or |
K | firstKey() | 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, or |
K | floorKey(K key) | Returns the greatest key less than or equal to the given key, or |
V | get(Object key) | Returns the value to which the specified key is mapped, or |
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. |
ConcurrentNavigableMap<K,V> | headMap(K toKey) | Returns a view of the portion of this map whose keys are strictly less than |
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, if |
Map.Entry<K,V> | higherEntry(K key) | Returns a key-value mapping associated with the least key strictly greater than the given key, or |
K | higherKey(K key) | Returns the least key strictly greater than the given key, or |
NavigableSet<K> | keySet() | Returns a |
Map.Entry<K,V> | lastEntry() | Returns a key-value mapping associated with the greatest key in this map, or |
K | lastKey() | 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, or |
K | lowerKey(K key) | Returns the greatest key strictly less than the given key, or |
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. |
Map.Entry<K,V> | pollFirstEntry() | Removes and returns a key-value mapping associated with the least key in this map, or |
Map.Entry<K,V> | pollLastEntry() | Removes and returns a key-value mapping associated with the greatest key in this map, or |
V | put(K key,
V value) | Associates the specified value with the specified key in this map. |
V | putIfAbsent(K key,
V value) | If the specified key is not already associated with a value, associates it with the given value. |
V | remove(Object key) | Removes the mapping for the specified key from this map if present. |
boolean | remove(Object key,
Object value) | Removes the entry for a key only if currently mapped to a given value. |
V | replace(K key,
V value) | Replaces the entry for a key only if 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. |
ConcurrentNavigableMap<K,V> | subMap(K fromKey,
boolean fromInclusive,
K toKey,
boolean toInclusive) | Returns a view of the portion of this map whose keys range from |
ConcurrentNavigableMap<K,V> | subMap(K fromKey,
K toKey) | Returns a view of the portion of this map whose keys range from |
ConcurrentNavigableMap<K,V> | tailMap(K fromKey) | Returns a view of the portion of this map whose keys are greater than or equal to |
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, if |
Collection<V> | values() | Returns a |
Methods declared in class java.util.AbstractMap
hashCode, isEmpty, putAll, size, toString
Methods declared in class java.lang.Object
finalize, getClass, notify, notifyAll, wait, wait, wait
Methods declared in interface java.util.concurrent.ConcurrentMap
forEach, replaceAll
Methods declared in interface java.util.concurrent.ConcurrentNavigableMap
descendingKeySet, descendingMap, navigableKeySet
Methods declared in interface java.util.Map
hashCode, isEmpty, putAll, size
Methods declared in interface java.util.SortedMap
comparator
Constructor Detail
ConcurrentSkipListMap
public ConcurrentSkipListMap()
Constructs a new, empty map, sorted according to the natural ordering of the keys.
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.
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 inm
are notComparable
, or are not mutually comparable -
NullPointerException
- if the specified map or any of its keys or values are null
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
Method Detail
clone
public ConcurrentSkipListMap<K,V> clone()
Returns a shallow copy of this ConcurrentSkipListMap
instance. (The keys and values themselves are not cloned.)
- Overrides:
-
clone
in classAbstractMap<K,V>
- Returns:
- a shallow copy of this map
- See Also:
Cloneable
containsKey
public boolean containsKey(Object key)
Returns true
if this map contains a mapping for the specified key.
- Specified by:
-
containsKey
in interfaceMap<K,V>
- Overrides:
-
containsKey
in classAbstractMap<K,V>
- Parameters:
-
key
- key whose presence in this map is to be tested - Returns:
-
true
if 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
get
public V get(Object key)
Returns the value to which the specified key is mapped, or null
if this map contains no mapping for the key.
More formally, if this map contains a mapping from a key k
to a value v
such that key
compares equal to k
according to the map's ordering, then this method returns v
; otherwise it returns null
. (There can be at most one such mapping.)
- Specified by:
-
get
in interfaceMap<K,V>
- Overrides:
-
get
in 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
null
if 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
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:
-
getOrDefault
in interfaceConcurrentMap<K,V>
- Specified by:
-
getOrDefault
in interfaceMap<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
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:
-
put
in interfaceMap<K,V>
- Overrides:
-
put
in classAbstractMap<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
null
if 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
remove
public V remove(Object key)
Removes the mapping for the specified key from this map if present.
- Specified by:
-
remove
in interfaceMap<K,V>
- Overrides:
-
remove
in classAbstractMap<K,V>
- Parameters:
-
key
- key for which mapping should be removed - Returns:
- the previous value associated with the specified key, or
null
if 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
containsValue
public boolean containsValue(Object value)
Returns true
if 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:
-
containsValue
in interfaceMap<K,V>
- Overrides:
-
containsValue
in classAbstractMap<K,V>
- Parameters:
-
value
- value whose presence in this map is to be tested - Returns:
-
true
if a mapping tovalue
exists;false
otherwise - Throws:
-
NullPointerException
- if the specified value is null
clear
public void clear()
Removes all of the mappings from this map.
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 unless null
. The function is NOT guaranteed to be applied once atomically only if the value is not present.
- Specified by:
-
computeIfAbsent
in interfaceConcurrentMap<K,V>
- Specified by:
-
computeIfAbsent
in interfaceMap<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
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:
-
computeIfPresent
in interfaceConcurrentMap<K,V>
- Specified by:
-
computeIfPresent
in interfaceMap<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
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 (or null
if there is no current mapping). The function is NOT guaranteed to be applied once atomically.
- Specified by:
-
compute
in interfaceConcurrentMap<K,V>
- Specified by:
-
compute
in interfaceMap<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
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 if null
. The function is NOT guaranteed to be applied once atomically.
- Specified by:
-
merge
in interfaceConcurrentMap<K,V>
- Specified by:
-
merge
in interfaceMap<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
keySet
public NavigableSet<K> keySet()
Returns a NavigableSet
view 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.SORTED
and Spliterator.ORDERED
, with an encounter order that is ascending key order.
The spliterator's comparator is null
if the map's comparator is null
. 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
, and clear
operations. It does not support the add
or addAll
operations.
The view's iterators and spliterators are weakly consistent.
This method is equivalent to method navigableKeySet
.
- Specified by:
-
keySet
in interfaceConcurrentNavigableMap<K,V>
- Specified by:
-
keySet
in interfaceMap<K,V>
- Specified by:
-
keySet
in interfaceSortedMap<K,V>
- Overrides:
-
keySet
in classAbstractMap<K,V>
- Returns:
- a navigable set view of the keys in this map
values
public Collection<V> values()
Returns a Collection
view 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.NONNULL
and Spliterator.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
, retainAll
and clear
operations. It does not support the add
or addAll
operations.
The view's iterators and spliterators are weakly consistent.
- Specified by:
-
values
in interfaceMap<K,V>
- Specified by:
-
values
in interfaceSortedMap<K,V>
- Overrides:
-
values
in classAbstractMap<K,V>
- Returns:
- a collection view of the values contained in this map
entrySet
public Set<Map.Entry<K,V>> entrySet()
Returns a Set
view 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.SORTED
and Spliterator.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
, retainAll
and clear
operations. It does not support the add
or addAll
operations.
The view's iterators and spliterators are weakly consistent.
The Map.Entry
elements traversed by the iterator
or spliterator
do not support the setValue
operation.
- Specified by:
-
entrySet
in interfaceMap<K,V>
- Specified by:
-
entrySet
in interfaceSortedMap<K,V>
- Returns:
- a set view of the mappings contained in this map, sorted in ascending key order
equals
public boolean equals(Object o)
Compares the specified object with this map for equality. Returns true
if the given object is also a map and the two maps represent the same mappings. More formally, two maps m1
and m2
represent the same mappings if m1.entrySet().equals(m2.entrySet())
. This operation may return misleading results if either map is concurrently modified during execution of this method.
- Specified by:
-
equals
in interfaceMap<K,V>
- Overrides:
-
equals
in classAbstractMap<K,V>
- Parameters:
-
o
- object to be compared for equality with this map - Returns:
-
true
if the specified object is equal to this map - See Also:
-
Object.hashCode()
,HashMap
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 this map
:
if (!map.containsKey(key)) return map.put(key, value); else return map.get(key);except that the action is performed atomically.
- Specified by:
-
putIfAbsent
in interfaceConcurrentMap<K,V>
- Specified by:
-
putIfAbsent
in interfaceMap<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
null
if 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
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 this map
:
if (map.containsKey(key) && Objects.equals(map.get(key), value)) { map.remove(key); return true; } else { return false; }except that the action is performed atomically.
- Specified by:
-
remove
in interfaceConcurrentMap<K,V>
- Specified by:
-
remove
in interfaceMap<K,V>
- Parameters:
-
key
- key with which the specified value is associated -
value
- value expected to be associated with the specified key - Returns:
-
true
if 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
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 this map
:
if (map.containsKey(key) && Objects.equals(map.get(key), oldValue)) { map.put(key, newValue); return true; } else { return false; }except that the action is performed atomically.
- Specified by:
-
replace
in interfaceConcurrentMap<K,V>
- Specified by:
-
replace
in interfaceMap<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:
-
true
if 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
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 this map
:
if (map.containsKey(key)) return map.put(key, value); else return null;except that the action is performed atomically.
- Specified by:
-
replace
in interfaceConcurrentMap<K,V>
- Specified by:
-
replace
in interfaceMap<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
null
if 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
firstKey
public K firstKey()
Description copied from interface: SortedMap
Returns the first (lowest) key currently in this map.
- Specified by:
-
firstKey
in interfaceSortedMap<K,V>
- Returns:
- the first (lowest) key currently in this map
- Throws:
-
NoSuchElementException
- if this map is empty
lastKey
public K lastKey()
Description copied from interface: SortedMap
Returns the last (highest) key currently in this map.
- Specified by:
-
lastKey
in interfaceSortedMap<K,V>
- Returns:
- the last (highest) key currently in this map
- Throws:
-
NoSuchElementException
- if this map is empty
subMap
public ConcurrentNavigableMap<K,V> subMap(K fromKey, boolean fromInclusive, K toKey, boolean toInclusive)
Description copied from interface: NavigableMap
Returns a view of the portion of this map whose keys range from fromKey
to toKey
. If fromKey
and toKey
are equal, the returned map is empty unless fromInclusive
and toInclusive
are 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 IllegalArgumentException
on 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:
-
subMap
in interfaceConcurrentNavigableMap<K,V>
- Specified by:
-
subMap
in interfaceNavigableMap<K,V>
- Parameters:
-
fromKey
- low endpoint of the keys in the returned map -
fromInclusive
-true
if the low endpoint is to be included in the returned view -
toKey
- high endpoint of the keys in the returned map -
toInclusive
-true
if the high endpoint is to be included in the returned view - Returns:
- a view of the portion of this map whose keys range from
fromKey
totoKey
- Throws:
-
ClassCastException
- iffromKey
andtoKey
cannot 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 iffromKey
ortoKey
cannot be compared to keys currently in the map. -
NullPointerException
- iffromKey
ortoKey
is null -
IllegalArgumentException
- iffromKey
is greater thantoKey
; or if this map itself has a restricted range, andfromKey
ortoKey
lies outside the bounds of the range
headMap
public ConcurrentNavigableMap<K,V> headMap(K toKey, boolean inclusive)
Description copied from interface: NavigableMap
Returns a view of the portion of this map whose keys are less than (or equal to, if inclusive
is 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 IllegalArgumentException
on an attempt to insert a key outside its range.
- Specified by:
-
headMap
in interfaceConcurrentNavigableMap<K,V>
- Specified by:
-
headMap
in interfaceNavigableMap<K,V>
- Parameters:
-
toKey
- high endpoint of the keys in the returned map -
inclusive
-true
if 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
inclusive
is true)toKey
- Throws:
-
ClassCastException
- iftoKey
is not compatible with this map's comparator (or, if the map has no comparator, iftoKey
does not implementComparable
). Implementations may, but are not required to, throw this exception iftoKey
cannot be compared to keys currently in the map. -
NullPointerException
- iftoKey
is null -
IllegalArgumentException
- if this map itself has a restricted range, andtoKey
lies outside the bounds of the range
tailMap
public ConcurrentNavigableMap<K,V> tailMap(K fromKey, boolean inclusive)
Description copied from interface: NavigableMap
Returns a view of the portion of this map whose keys are greater than (or equal to, if inclusive
is 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 IllegalArgumentException
on an attempt to insert a key outside its range.
- Specified by:
-
tailMap
in interfaceConcurrentNavigableMap<K,V>
- Specified by:
-
tailMap
in interfaceNavigableMap<K,V>
- Parameters:
-
fromKey
- low endpoint of the keys in the returned map -
inclusive
-true
if 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
inclusive
is true)fromKey
- Throws:
-
ClassCastException
- iffromKey
is not compatible with this map's comparator (or, if the map has no comparator, iffromKey
does not implementComparable
). Implementations may, but are not required to, throw this exception iffromKey
cannot be compared to keys currently in the map. -
NullPointerException
- iffromKey
is null -
IllegalArgumentException
- if this map itself has a restricted range, andfromKey
lies outside the bounds of the range
subMap
public ConcurrentNavigableMap<K,V> subMap(K fromKey, K toKey)
Description copied from interface: NavigableMap
Returns a view of the portion of this map whose keys range from fromKey
, inclusive, to toKey
, exclusive. (If fromKey
and toKey
are 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 IllegalArgumentException
on an attempt to insert a key outside its range.
Equivalent to subMap(fromKey, true, toKey, false)
.
- Specified by:
-
subMap
in interfaceConcurrentNavigableMap<K,V>
- Specified by:
-
subMap
in interfaceNavigableMap<K,V>
- Specified by:
-
subMap
in interfaceSortedMap<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
- iffromKey
andtoKey
cannot 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 iffromKey
ortoKey
cannot be compared to keys currently in the map. -
NullPointerException
- iffromKey
ortoKey
is null -
IllegalArgumentException
- iffromKey
is greater thantoKey
; or if this map itself has a restricted range, andfromKey
ortoKey
lies outside the bounds of the range
headMap
public ConcurrentNavigableMap<K,V> headMap(K toKey)
Description copied from interface: NavigableMap
Returns a view of the portion of this map whose keys are strictly less than 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 IllegalArgumentException
on an attempt to insert a key outside its range.
Equivalent to headMap(toKey, false)
.
- Specified by:
-
headMap
in interfaceConcurrentNavigableMap<K,V>
- Specified by:
-
headMap
in interfaceNavigableMap<K,V>
- Specified by:
-
headMap
in 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
- iftoKey
is not compatible with this map's comparator (or, if the map has no comparator, iftoKey
does not implementComparable
). Implementations may, but are not required to, throw this exception iftoKey
cannot be compared to keys currently in the map. -
NullPointerException
- iftoKey
is null -
IllegalArgumentException
- if this map itself has a restricted range, andtoKey
lies outside the bounds of the range
tailMap
public ConcurrentNavigableMap<K,V> tailMap(K fromKey)
Description copied from interface: NavigableMap
Returns a view of the portion of this map whose keys are greater than or equal to 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 IllegalArgumentException
on an attempt to insert a key outside its range.
Equivalent to tailMap(fromKey, true)
.
- Specified by:
-
tailMap
in interfaceConcurrentNavigableMap<K,V>
- Specified by:
-
tailMap
in interfaceNavigableMap<K,V>
- Specified by:
-
tailMap
in 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
- iffromKey
is not compatible with this map's comparator (or, if the map has no comparator, iffromKey
does not implementComparable
). Implementations may, but are not required to, throw this exception iffromKey
cannot be compared to keys currently in the map. -
NullPointerException
- iffromKey
is null -
IllegalArgumentException
- if this map itself has a restricted range, andfromKey
lies outside the bounds of the range
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, or null
if there is no such key. The returned entry does not support the Entry.setValue
method.
- Specified by:
-
lowerEntry
in interfaceNavigableMap<K,V>
- Parameters:
-
key
- the key - Returns:
- an entry with the greatest key less than
key
, ornull
if 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
lowerKey
public K lowerKey(K key)
Description copied from interface: NavigableMap
Returns the greatest key strictly less than the given key, or null
if there is no such key.
- Specified by:
-
lowerKey
in interfaceNavigableMap<K,V>
- Parameters:
-
key
- the key - Returns:
- the greatest key less than
key
, ornull
if 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
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, or null
if there is no such key. The returned entry does not support the Entry.setValue
method.
- Specified by:
-
floorEntry
in interfaceNavigableMap<K,V>
- Parameters:
-
key
- the key - Returns:
- an entry with the greatest key less than or equal to
key
, ornull
if 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
floorKey
public K floorKey(K key)
Description copied from interface: NavigableMap
Returns the greatest key less than or equal to the given key, or null
if there is no such key.
- Specified by:
-
floorKey
in interfaceNavigableMap<K,V>
- Parameters:
-
key
- the key - Returns:
- the greatest key less than or equal to
key
, ornull
if 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
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, or null
if there is no such entry. The returned entry does not support the Entry.setValue
method.
- Specified by:
-
ceilingEntry
in interfaceNavigableMap<K,V>
- Parameters:
-
key
- the key - Returns:
- an entry with the least key greater than or equal to
key
, ornull
if 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
ceilingKey
public K ceilingKey(K key)
Description copied from interface: NavigableMap
Returns the least key greater than or equal to the given key, or null
if there is no such key.
- Specified by:
-
ceilingKey
in interfaceNavigableMap<K,V>
- Parameters:
-
key
- the key - Returns:
- the least key greater than or equal to
key
, ornull
if 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
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, or null
if there is no such key. The returned entry does not support the Entry.setValue
method.
- Specified by:
-
higherEntry
in interfaceNavigableMap<K,V>
- Parameters:
-
key
- the key - Returns:
- an entry with the least key greater than
key
, ornull
if 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
higherKey
public K higherKey(K key)
Description copied from interface: NavigableMap
Returns the least key strictly greater than the given key, or null
if there is no such key.
- Specified by:
-
higherKey
in interfaceNavigableMap<K,V>
- Parameters:
-
key
- the key - Returns:
- the least key greater than
key
, ornull
if 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
firstEntry
public Map.Entry<K,V> firstEntry()
Returns a key-value mapping associated with the least key in this map, or null
if the map is empty. The returned entry does not support the Entry.setValue
method.
- Specified by:
-
firstEntry
in interfaceNavigableMap<K,V>
- Returns:
- an entry with the least key, or
null
if this map is empty
lastEntry
public Map.Entry<K,V> lastEntry()
Returns a key-value mapping associated with the greatest key in this map, or null
if the map is empty. The returned entry does not support the Entry.setValue
method.
- Specified by:
-
lastEntry
in interfaceNavigableMap<K,V>
- Returns:
- an entry with the greatest key, or
null
if this map is empty
pollFirstEntry
public Map.Entry<K,V> pollFirstEntry()
Removes and returns a key-value mapping associated with the least key in this map, or null
if the map is empty. The returned entry does not support the Entry.setValue
method.
- Specified by:
-
pollFirstEntry
in interfaceNavigableMap<K,V>
- Returns:
- the removed first entry of this map, or
null
if this map is empty
pollLastEntry
public Map.Entry<K,V> pollLastEntry()
Removes and returns a key-value mapping associated with the greatest key in this map, or null
if the map is empty. The returned entry does not support the Entry.setValue
method.
- Specified by:
-
pollLastEntry
in interfaceNavigableMap<K,V>
- Returns:
- the removed last entry of this map, or
null
if this map is empty