| java.util.NavigableMap
| NavigableMap | | public interface NavigableMap extends SortedMap<K, V>(Code) | | 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
NavigableMap.subMap(Object,Object) subMap(K, K) ,
NavigableMap.headMap(Object) headMap(K) , and
NavigableMap.tailMap(Object) 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,
NavigableMap.keySet() can be overriden to return
NavigableSet .
This interface is a member of the
Java Collections Framework.
author:
Doug Lea
author:
Josh Bloch<
Parameters:
K - > the type of keys maintained by this map<
Parameters:
V - > the type of mapped values
since:
1.6 |
| Method Summary | |
| 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 key. | | K | ceilingKey(K key)
Returns the least key greater than or equal to the given key,
or
null if there is no such key. | | NavigableSet<K> | descendingKeySet()
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. | | NavigableMap<K, V> | descendingMap()
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. | | 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. | | 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. | | K | floorKey(K key)
Returns the greatest key less than or equal to the given key,
or
null if there is no such key. | | NavigableMap<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
inclusive is true)
toKey . | | SortedMap<K, V> | headMap(K toKey)
Equivalent to
headMap(toKey, false) . | | 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. | | K | higherKey(K key)
Returns the least key strictly greater than the given key, or
null if there is no such key. | | 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. | | 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. | | K | lowerKey(K key)
Returns the greatest key strictly less than the given key, or
null if there is no such key. | | NavigableSet<K> | navigableKeySet()
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. | | 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. | | 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. | | NavigableMap<K, V> | subMap(K fromKey, boolean fromInclusive, K toKey, boolean toInclusive)
Returns a view of the portion of this map whose keys range from
fromKey to
toKey . | | SortedMap<K, V> | subMap(K fromKey, K toKey)
Equivalent to
subMap(fromKey, true, toKey, false) . | | NavigableMap<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
inclusive is true)
fromKey . | | SortedMap<K, V> | tailMap(K fromKey)
Equivalent to
tailMap(fromKey, true) . |
| ceilingEntry | | Map.Entry<K, V> ceilingEntry(K key)(Code) | | 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.
Parameters:
key - the key an entry with the least key greater than or equal to key , or null if there is no such key
throws:
ClassCastException - if the specified key cannot be comparedwith the keys currently in the map
throws:
NullPointerException - if the specified key is nulland this map does not permit null keys |
| ceilingKey | | K ceilingKey(K key)(Code) | | Returns the least key greater than or equal to the given key,
or
null if there is no such key.
Parameters:
key - the key the least key greater than or equal to key ,or null if there is no such key
throws:
ClassCastException - if the specified key cannot be comparedwith the keys currently in the map
throws:
NullPointerException - if the specified key is nulland this map does not permit null keys |
| descendingKeySet | | NavigableSet<K> descendingKeySet()(Code) | | 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.
a reverse order navigable set view of the keys in this map |
| descendingMap | | NavigableMap<K, V> descendingMap()(Code) | | 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) Collections.reverseOrder (comparator()).
The expression
m.descendingMap().descendingMap() returns a
view of
m essentially equivalent to
m .
a reverse order view of this map |
| firstEntry | | Map.Entry<K, V> firstEntry()(Code) | | Returns a key-value mapping associated with the least
key in this map, or
null if the map is empty.
an entry with the least key,or null if this map is empty |
| floorEntry | | Map.Entry<K, V> floorEntry(K key)(Code) | | 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.
Parameters:
key - the key an entry with the greatest key less than or equal to key , or null if there is no such key
throws:
ClassCastException - if the specified key cannot be comparedwith the keys currently in the map
throws:
NullPointerException - if the specified key is nulland this map does not permit null keys |
| floorKey | | K floorKey(K key)(Code) | | Returns the greatest key less than or equal to the given key,
or
null if there is no such key.
Parameters:
key - the key the greatest key less than or equal to key ,or null if there is no such key
throws:
ClassCastException - if the specified key cannot be comparedwith the keys currently in the map
throws:
NullPointerException - if the specified key is nulland this map does not permit null keys |
| headMap | | NavigableMap<K, V> headMap(K toKey, boolean inclusive)(Code) | | 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.
Parameters:
toKey - high endpoint of the keys in the returned map
Parameters:
inclusive - true if the high endpointis to be included in the returned view a view of the portion of this map whose keys are less than(or equal to, if inclusive is true) toKey
throws:
ClassCastException - if toKey is not compatiblewith 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 thisexception if toKey cannot be compared to keyscurrently in the map.
throws:
NullPointerException - if toKey is nulland this map does not permit null keys
throws:
IllegalArgumentException - if this map itself has arestricted range, and toKey lies outside thebounds of the range |
| higherEntry | | Map.Entry<K, V> higherEntry(K key)(Code) | | Returns a key-value mapping associated with the least key
strictly greater than the given key, or
null if there
is no such key.
Parameters:
key - the key an entry with the least key greater than key ,or null if there is no such key
throws:
ClassCastException - if the specified key cannot be comparedwith the keys currently in the map
throws:
NullPointerException - if the specified key is nulland this map does not permit null keys |
| higherKey | | K higherKey(K key)(Code) | | Returns the least key strictly greater than the given key, or
null if there is no such key.
Parameters:
key - the key the least key greater than key ,or null if there is no such key
throws:
ClassCastException - if the specified key cannot be comparedwith the keys currently in the map
throws:
NullPointerException - if the specified key is nulland this map does not permit null keys |
| lastEntry | | Map.Entry<K, V> lastEntry()(Code) | | Returns a key-value mapping associated with the greatest
key in this map, or
null if the map is empty.
an entry with the greatest key,or null if this map is empty |
| lowerEntry | | Map.Entry<K, V> lowerEntry(K key)(Code) | | Returns a key-value mapping associated with the greatest key
strictly less than the given key, or
null if there is
no such key.
Parameters:
key - the key an entry with the greatest key less than key ,or null if there is no such key
throws:
ClassCastException - if the specified key cannot be comparedwith the keys currently in the map
throws:
NullPointerException - if the specified key is nulland this map does not permit null keys |
| lowerKey | | K lowerKey(K key)(Code) | | Returns the greatest key strictly less than the given key, or
null if there is no such key.
Parameters:
key - the key the greatest key less than key ,or null if there is no such key
throws:
ClassCastException - if the specified key cannot be comparedwith the keys currently in the map
throws:
NullPointerException - if the specified key is nulland this map does not permit null keys |
| navigableKeySet | | NavigableSet<K> navigableKeySet()(Code) | | 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.
a navigable set view of the keys in this map |
| pollFirstEntry | | Map.Entry<K, V> pollFirstEntry()(Code) | | Removes and returns a key-value mapping associated with
the least key in this map, or
null if the map is empty.
the removed first entry of this map,or null if this map is empty |
| pollLastEntry | | Map.Entry<K, V> pollLastEntry()(Code) | | Removes and returns a key-value mapping associated with
the greatest key in this map, or
null if the map is empty.
the removed last entry of this map,or null if this map is empty |
| subMap | | NavigableMap<K, V> subMap(K fromKey, boolean fromInclusive, K toKey, boolean toInclusive)(Code) | | 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.
Parameters:
fromKey - low endpoint of the keys in the returned map
Parameters:
fromInclusive - true if the low endpointis to be included in the returned view
Parameters:
toKey - high endpoint of the keys in the returned map
Parameters:
toInclusive - true if the high endpointis to be included in the returned view a view of the portion of this map whose keys range from fromKey to toKey
throws:
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 thisexception if fromKey or toKey cannot be compared to keys currently in the map.
throws:
NullPointerException - if fromKey or toKey is null and this map does not permit null keys
throws:
IllegalArgumentException - if fromKey is greater than toKey ; or if this map itself has a restrictedrange, and fromKey or toKey liesoutside the bounds of the range |
| tailMap | | NavigableMap<K, V> tailMap(K fromKey, boolean inclusive)(Code) | | 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.
Parameters:
fromKey - low endpoint of the keys in the returned map
Parameters:
inclusive - true if the low endpointis to be included in the returned view a view of the portion of this map whose keys are greater than(or equal to, if inclusive is true) fromKey
throws:
ClassCastException - if fromKey is not compatiblewith 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 thisexception if fromKey cannot be compared to keyscurrently in the map.
throws:
NullPointerException - if fromKey is nulland this map does not permit null keys
throws:
IllegalArgumentException - if this map itself has arestricted range, and fromKey lies outside thebounds of the range |
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