java.util.NavigableMap<K, V> |
Known Indirect Subclasses
|
A SortedMap
extended with navigation methods returning the
closest matches for given search targets. Methods
lowerEntry
, floorEntry
, ceilingEntry
,
and higherEntry
return Map.Entry
objects
associated with keys respectively less than, less than or equal,
greater than or equal, and greater than a given key, returning
null
if there is no such key. Similarly, methods
lowerKey
, floorKey
, ceilingKey
, and
higherKey
return only the associated keys. All of these
methods are designed for locating, not traversing entries.
A NavigableMap
may be accessed and traversed in either
ascending or descending key order. The descendingMap
method returns a view of the map with the senses of all relational
and directional methods inverted. The performance of ascending
operations and views is likely to be faster than that of descending
ones. Methods subMap
, headMap
,
and tailMap
differ from the like-named SortedMap
methods in accepting additional arguments describing
whether lower and upper bounds are inclusive versus exclusive.
Submaps of any NavigableMap
must implement the NavigableMap
interface.
This interface additionally defines methods firstEntry
,
pollFirstEntry
, lastEntry
, and
pollLastEntry
that return and/or remove the least and
greatest mappings, if any exist, else returning null
.
Implementations of entry-returning methods are expected to
return Map.Entry
pairs representing snapshots of mappings
at the time they were produced, and thus generally do not
support the optional Entry.setValue
method. Note however
that it is possible to change mappings in the associated map using
method put
.
Methods
subMap(K, K)
,
headMap(K)
, and
tailMap(K)
are specified to return SortedMap
to allow existing
implementations of SortedMap
to be compatibly retrofitted to
implement NavigableMap
, but extensions and implementations
of this interface are encouraged to override these methods to return
NavigableMap
. Similarly,
keySet()
can be overriden to return NavigableSet
.
Public Methods | |||||||||||
---|---|---|---|---|---|---|---|---|---|---|---|
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 key. | |||||||||||
Returns the least key greater than or equal to the given key,
or
null if there is no such key. | |||||||||||
Returns a reverse order
NavigableSet view of the keys contained in this map. | |||||||||||
Returns a reverse order view of the mappings contained in this map.
| |||||||||||
Returns a key-value mapping associated with the least
key in this map, or
null if the map is empty. | |||||||||||
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. | |||||||||||
Returns the greatest key less than or equal to the given key,
or
null if there is no such key. | |||||||||||
Returns a view of the portion of this map whose keys are less than (or
equal to, if
inclusive is true) toKey . | |||||||||||
Returns a sorted map over a range of this sorted map with all keys that
are less than the specified
endKey .
Equivalent to | |||||||||||
Returns a key-value mapping associated with the least key
strictly greater than the given key, or
null if there
is no such key. | |||||||||||
Returns the least key strictly greater than the given key, or
null if there is no such key. | |||||||||||
Returns a key-value mapping associated with the greatest
key in this map, or
null if the map is empty. | |||||||||||
Returns a key-value mapping associated with the greatest key
strictly less than the given key, or
null if there is
no such key. | |||||||||||
Returns the greatest key strictly less than the given key, or
null if there is no such key. | |||||||||||
Returns a
NavigableSet view of the keys contained in this map. | |||||||||||
Removes and returns a key-value mapping associated with
the least key in this map, or
null if the map is empty. | |||||||||||
Removes and returns a key-value mapping associated with
the greatest key in this map, or
null if the map is empty. | |||||||||||
Returns a sorted map over a range of this sorted map with all keys
greater than or equal to the specified
startKey and less than the
specified endKey .
Equivalent to | |||||||||||
Returns a view of the portion of this map whose keys range from
fromKey to toKey . | |||||||||||
Returns a sorted map over a range of this sorted map with all keys that
are greater than or equal to the specified
startKey .
Equivalent to | |||||||||||
Returns a view of the portion of this map whose keys are greater than (or
equal to, if
inclusive is true) fromKey . |
[Expand]
Inherited Methods | |||||||||||
---|---|---|---|---|---|---|---|---|---|---|---|
From interface
java.util.Map
| |||||||||||
From interface
java.util.SortedMap
|
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 key.
key | the key |
---|
key
, or null
if there is no such keyClassCastException | if the specified key cannot be compared with the keys currently in the map |
---|---|
NullPointerException | if the specified key is null and this map does not permit null keys |
Returns the least key greater than or equal to the given key,
or null
if there is no such key.
key | the key |
---|
key
,
or null
if there is no such keyClassCastException | if the specified key cannot be compared with the keys currently in the map |
---|---|
NullPointerException | if the specified key is null and this map does not permit null keys |
Returns a reverse order NavigableSet
view 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. If the map is modified while an iteration
over the set is in progress (except through the iterator's own remove
operation), the results of the iteration are undefined. 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.
Returns 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. If either map is
modified while an iteration over a collection view of either map
is in progress (except through the iterator's own remove
operation), the results of the iteration are undefined.
The returned map has an ordering equivalent to
Collections.reverseOrder
(comparator()).
The expression m.descendingMap().descendingMap()
returns a
view of m
essentially equivalent to m
.
Returns a key-value mapping associated with the least
key in this map, or null
if the map is empty.
null
if this map is empty
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.
key | the key |
---|
key
, or null
if there is no such keyClassCastException | if the specified key cannot be compared with the keys currently in the map |
---|---|
NullPointerException | if the specified key is null and this map does not permit null keys |
Returns the greatest key less than or equal to the given key,
or null
if there is no such key.
key | the key |
---|
key
,
or null
if there is no such keyClassCastException | if the specified key cannot be compared with the keys currently in the map |
---|---|
NullPointerException | if the specified key is null and this map does not permit null keys |
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.
toKey | high endpoint of the keys in the returned map |
---|---|
inclusive | true if the high endpoint
is to be included in the returned view |
inclusive
is true) toKey
ClassCastException | if toKey is not compatible
with this map's comparator (or, if the map has no comparator,
if toKey does not implement Comparable ).
Implementations may, but are not required to, throw this
exception if toKey cannot be compared to keys
currently in the map. |
---|---|
NullPointerException | if toKey is null
and this map does not permit null keys |
IllegalArgumentException | if this map itself has a
restricted range, and toKey lies outside the
bounds of the range
|
Returns a sorted map over a range of this sorted map with all keys that
are less than the specified endKey
. Changes to the returned
sorted map are reflected in this sorted map and vice versa.
Note: The returned map will not allow an insertion of a key outside the specified range.
Equivalent to headMap(toKey, false)
.
toKey | the high boundary of the range specified. |
---|
endKey
.Returns a key-value mapping associated with the least key
strictly greater than the given key, or null
if there
is no such key.
key | the key |
---|
key
,
or null
if there is no such keyClassCastException | if the specified key cannot be compared with the keys currently in the map |
---|---|
NullPointerException | if the specified key is null and this map does not permit null keys |
Returns the least key strictly greater than the given key, or
null
if there is no such key.
key | the key |
---|
key
,
or null
if there is no such keyClassCastException | if the specified key cannot be compared with the keys currently in the map |
---|---|
NullPointerException | if the specified key is null and this map does not permit null keys |
Returns a key-value mapping associated with the greatest
key in this map, or null
if the map is empty.
null
if this map is empty
Returns a key-value mapping associated with the greatest key
strictly less than the given key, or null
if there is
no such key.
key | the key |
---|
key
,
or null
if there is no such keyClassCastException | if the specified key cannot be compared with the keys currently in the map |
---|---|
NullPointerException | if the specified key is null and this map does not permit null keys |
Returns the greatest key strictly less than the given key, or
null
if there is no such key.
key | the key |
---|
key
,
or null
if there is no such keyClassCastException | if the specified key cannot be compared with the keys currently in the map |
---|---|
NullPointerException | if the specified key is null and this map does not permit null keys |
Returns a NavigableSet
view of the keys contained in this map.
The set's iterator returns the keys in ascending order.
The set is backed by the map, so changes to the map are reflected in
the set, and vice-versa. If the map is modified while an iteration
over the set is in progress (except through the iterator's own remove
operation), the results of the iteration are undefined. 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.
Removes and returns a key-value mapping associated with
the least key in this map, or null
if the map is empty.
null
if this map is empty
Removes and returns a key-value mapping associated with
the greatest key in this map, or null
if the map is empty.
null
if this map is empty
Returns a sorted map over a range of this sorted map with all keys
greater than or equal to the specified startKey
and less than the
specified endKey
. Changes to the returned sorted map are
reflected in this sorted map and vice versa.
Note: The returned map will not allow an insertion of a key outside the specified range.
Equivalent to subMap(fromKey, true, toKey, false)
.
fromKey | the low boundary of the range (inclusive). |
---|---|
toKey | the high boundary of the range (exclusive), |
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
fromExclusive
and toExclusive
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.
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 |
fromKey
to toKey
ClassCastException | if fromKey and toKey
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 if fromKey or toKey
cannot be compared to keys currently in the map. |
---|---|
NullPointerException | if fromKey or toKey
is null and this map does not permit null keys |
IllegalArgumentException | if fromKey is greater than
toKey ; or if this map itself has a restricted
range, and fromKey or toKey lies
outside the bounds of the range
|
Returns a sorted map over a range of this sorted map with all keys that
are greater than or equal to the specified startKey
. Changes to
the returned sorted map are reflected in this sorted map and vice versa.
Note: The returned map will not allow an insertion of a key outside the specified range.
Equivalent to tailMap(fromKey, true)
.
fromKey | the low boundary of the range specified. |
---|
startKey
.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.
fromKey | low endpoint of the keys in the returned map |
---|---|
inclusive | true if the low endpoint
is to be included in the returned view |
inclusive
is true) fromKey
ClassCastException | if fromKey is not compatible
with this map's comparator (or, if the map has no comparator,
if fromKey does not implement Comparable ).
Implementations may, but are not required to, throw this
exception if fromKey cannot be compared to keys
currently in the map. |
---|---|
NullPointerException | if fromKey is null
and this map does not permit null keys |
IllegalArgumentException | if this map itself has a
restricted range, and fromKey lies outside the
bounds of the range
|