NavigableMap
interface NavigableMap<K : Any!, V : Any!> : SortedMap<K, V>
| java.util.NavigableMap |
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(K, boolean, K, boolean), headMap(K, boolean), and tailMap(K, boolean) 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.
The methods ceilingEntry, firstEntry, floorEntry, higherEntry, lastEntry, lowerEntry, pollFirstEntry, and pollLastEntry return Map.Entry instances that represent snapshots of mappings as of the time of the call. They do not support mutation of the underlying map via the optional setValue method.
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 overridden to return NavigableSet.
Summary
| Public methods | |
|---|---|
| abstract MutableEntry<K, V>? |
ceilingEntry(: K)Returns a key-value mapping associated with the least key greater than or equal to the given key, or |
| abstract K? |
ceilingKey(: K)Returns the least key greater than or equal to the given key, or |
| abstract NavigableSet<K> |
Returns a reverse order |
| abstract NavigableMap<K, V> |
Returns a reverse order view of the mappings contained in this map. |
| abstract MutableEntry<K, V>? |
Returns a key-value mapping associated with the least key in this map, or |
| abstract MutableEntry<K, V>? |
floorEntry(: K)Returns a key-value mapping associated with the greatest key less than or equal to the given key, or |
| abstract K? |
floorKey(: K)Returns the greatest key less than or equal to the given key, or |
| abstract NavigableMap<K, V> |
Returns a view of the portion of this map whose keys are less than (or equal to, if |
| abstract SortedMap<K, V> |
headMap(: K)Returns a view of the portion of this map whose keys are strictly less than |
| abstract MutableEntry<K, V>? |
higherEntry(: K)Returns a key-value mapping associated with the least key strictly greater than the given key, or |
| abstract K? |
higherKey(: K)Returns the least key strictly greater than the given key, or |
| abstract MutableEntry<K, V>? |
Returns a key-value mapping associated with the greatest key in this map, or |
| abstract MutableEntry<K, V>? |
lowerEntry(: K)Returns a key-value mapping associated with the greatest key strictly less than the given key, or |
| abstract K? |
lowerKey(: K)Returns the greatest key strictly less than the given key, or |
| abstract NavigableSet<K> |
Returns a |
| abstract MutableEntry<K, V>? |
Removes and returns a key-value mapping associated with the least key in this map, or |
| abstract MutableEntry<K, V>? |
Removes and returns a key-value mapping associated with the greatest key in this map, or |
| open NavigableMap<K, V> |
reversed()Returns a reverse-ordered view of this map. |
| abstract NavigableMap<K, V> |
Returns a view of the portion of this map whose keys range from |
| abstract SortedMap<K, V> |
subMap(: K, : K)Returns a view of the portion of this map whose keys range from |
| abstract NavigableMap<K, V> |
Returns a view of the portion of this map whose keys are greater than (or equal to, if |
| abstract SortedMap<K, V> |
tailMap(: K)Returns a view of the portion of this map whose keys are greater than or equal to |
| Inherited functions | |
|---|---|
| Inherited properties | |
|---|---|
Public methods
ceilingEntry
abstract fun ceilingEntry(: K): MutableEntry<K, V>?
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 |
K: the key |
| Return | |
|---|---|
MutableEntry<K, V>? |
an entry with the least key greater than or equal to key, or null if there is no such key |
| Exceptions | |
|---|---|
java.lang.ClassCastException |
if the specified key cannot be compared with the keys currently in the map |
java.lang.NullPointerException |
if the specified key is null and this map does not permit null keys |
ceilingKey
abstract fun ceilingKey(: K): K?
Returns the least key greater than or equal to the given key, or null if there is no such key.
| Parameters | |
|---|---|
key |
K: the key |
| Return | |
|---|---|
K? |
the least key greater than or equal to key, or null if there is no such key |
| Exceptions | |
|---|---|
java.lang.ClassCastException |
if the specified key cannot be compared with the keys currently in the map |
java.lang.NullPointerException |
if the specified key is null and this map does not permit null keys |
descendingKeySet
abstract fun descendingKeySet(): NavigableSet<K>
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.
| Return | |
|---|---|
NavigableSet<K> |
a reverse order navigable set view of the keys in this map |
descendingMap
abstract fun descendingMap(): NavigableMap<K, V>
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.
| Return | |
|---|---|
NavigableMap<K, V> |
a reverse order view of this map |
firstEntry
abstract fun firstEntry(): MutableEntry<K, V>?
Returns a key-value mapping associated with the least key in this map, or null if the map is empty.
| Return | |
|---|---|
MutableEntry<K, V>? |
an entry with the least key, or null if this map is empty |
floorEntry
abstract fun floorEntry(: K): MutableEntry<K, V>?
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 |
K: the key |
| Return | |
|---|---|
MutableEntry<K, V>? |
an entry with the greatest key less than or equal to key, or null if there is no such key |
| Exceptions | |
|---|---|
java.lang.ClassCastException |
if the specified key cannot be compared with the keys currently in the map |
java.lang.NullPointerException |
if the specified key is null and this map does not permit null keys |
floorKey
abstract fun floorKey(: K): K?
Returns the greatest key less than or equal to the given key, or null if there is no such key.
| Parameters | |
|---|---|
key |
K: the key |
| Return | |
|---|---|
K? |
the greatest key less than or equal to key, or null if there is no such key |
| Exceptions | |
|---|---|
java.lang.ClassCastException |
if the specified key cannot be compared with the keys currently in the map |
java.lang.NullPointerException |
if the specified key is null and this map does not permit null keys |
headMap
abstract fun headMap(
: K,
: Boolean
): NavigableMap<K, V>
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 |
K: high endpoint of the keys in the returned map |
inclusive |
Boolean: true if the high endpoint is to be included in the returned view |
| Return | |
|---|---|
NavigableMap<K, V> |
a view of the portion of this map whose keys are less than (or equal to, if inclusive is true) toKey |
| Exceptions | |
|---|---|
java.lang.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. |
java.lang.NullPointerException |
if toKey is null and this map does not permit null keys |
java.lang.IllegalArgumentException |
if this map itself has a restricted range, and toKey lies outside the bounds of the range |
headMap
abstract fun headMap(: K): SortedMap<K, V>
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).
| Parameters | |
|---|---|
toKey |
K: high endpoint (exclusive) of the keys in the returned map |
| Return | |
|---|---|
SortedMap<K, V> |
a view of the portion of this map whose keys are strictly less than toKey |
| Exceptions | |
|---|---|
java.lang.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. |
java.lang.NullPointerException |
if toKey is null and this map does not permit null keys |
java.lang.IllegalArgumentException |
if this map itself has a restricted range, and toKey lies outside the bounds of the range |
higherEntry
abstract fun higherEntry(: K): MutableEntry<K, V>?
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 |
K: the key |
| Return | |
|---|---|
MutableEntry<K, V>? |
an entry with the least key greater than key, or null if there is no such key |
| Exceptions | |
|---|---|
java.lang.ClassCastException |
if the specified key cannot be compared with the keys currently in the map |
java.lang.NullPointerException |
if the specified key is null and this map does not permit null keys |
higherKey
abstract fun higherKey(: K): K?
Returns the least key strictly greater than the given key, or null if there is no such key.
| Parameters | |
|---|---|
key |
K: the key |
| Return | |
|---|---|
K? |
the least key greater than key, or null if there is no such key |
| Exceptions | |
|---|---|
java.lang.ClassCastException |
if the specified key cannot be compared with the keys currently in the map |
java.lang.NullPointerException |
if the specified key is null and this map does not permit null keys |
lastEntry
abstract fun lastEntry(): MutableEntry<K, V>?
Returns a key-value mapping associated with the greatest key in this map, or null if the map is empty.
| Return | |
|---|---|
MutableEntry<K, V>? |
an entry with the greatest key, or null if this map is empty |
lowerEntry
abstract fun lowerEntry(: K): MutableEntry<K, V>?
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 |
K: the key |
| Return | |
|---|---|
MutableEntry<K, V>? |
an entry with the greatest key less than key, or null if there is no such key |
| Exceptions | |
|---|---|
java.lang.ClassCastException |
if the specified key cannot be compared with the keys currently in the map |
java.lang.NullPointerException |
if the specified key is null and this map does not permit null keys |
lowerKey
abstract fun lowerKey(: K): K?
Returns the greatest key strictly less than the given key, or null if there is no such key.
| Parameters | |
|---|---|
key |
K: the key |
| Return | |
|---|---|
K? |
the greatest key less than key, or null if there is no such key |
| Exceptions | |
|---|---|
java.lang.ClassCastException |
if the specified key cannot be compared with the keys currently in the map |
java.lang.NullPointerException |
if the specified key is null and this map does not permit null keys |
navigableKeySet
abstract fun navigableKeySet(): NavigableSet<K>
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.
| Return | |
|---|---|
NavigableSet<K> |
a navigable set view of the keys in this map |
pollFirstEntry
abstract fun pollFirstEntry(): MutableEntry<K, V>?
Removes and returns a key-value mapping associated with the least key in this map, or null if the map is empty.
| Return | |
|---|---|
MutableEntry<K, V>? |
the removed first entry of this map, or null if this map is empty |
| Exceptions | |
|---|---|
java.lang.UnsupportedOperationException |
if this collection implementation does not support this operation |
pollLastEntry
abstract fun pollLastEntry(): MutableEntry<K, V>?
Removes and returns a key-value mapping associated with the greatest key in this map, or null if the map is empty.
| Return | |
|---|---|
MutableEntry<K, V>? |
the removed last entry of this map, or null if this map is empty |
| Exceptions | |
|---|---|
java.lang.UnsupportedOperationException |
if this collection implementation does not support this operation |
reversed
open fun reversed(): NavigableMap<K, V>
Returns a reverse-ordered view of this map. The encounter order of mappings in the returned view is the inverse of the encounter order of mappings in this map. The reverse ordering affects all order-sensitive operations, including those on the view collections of the returned view. If the implementation permits modifications to this view, the modifications "write through" to the underlying map. Changes to the underlying map might or might not be visible in this reversed view, depending upon the implementation.
This method is equivalent to descendingMap.
| Return | |
|---|---|
NavigableMap<K, V> |
a reverse-ordered view of this map, as a NavigableMap |
subMap
abstract fun subMap(
: K,
: Boolean,
: K,
: Boolean
): NavigableMap<K, V>
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.
| Parameters | |
|---|---|
fromKey |
K: low endpoint of the keys in the returned map |
fromInclusive |
Boolean: true if the low endpoint is to be included in the returned view |
toKey |
K: high endpoint of the keys in the returned map |
toInclusive |
Boolean: true if the high endpoint is to be included in the returned view |
| Return | |
|---|---|
NavigableMap<K, V> |
a view of the portion of this map whose keys range from fromKey to toKey |
| Exceptions | |
|---|---|
java.lang.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. |
java.lang.NullPointerException |
if fromKey or toKey is null and this map does not permit null keys |
java.lang.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 |
subMap
abstract fun subMap(
: K,
: K
): SortedMap<K, V>
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).
| Parameters | |
|---|---|
fromKey |
K: low endpoint (inclusive) of the keys in the returned map |
toKey |
K: high endpoint (exclusive) of the keys in the returned map |
| Return | |
|---|---|
SortedMap<K, V> |
a view of the portion of this map whose keys range from fromKey, inclusive, to toKey, exclusive |
| Exceptions | |
|---|---|
java.lang.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. |
java.lang.NullPointerException |
if fromKey or toKey is null and this map does not permit null keys |
java.lang.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 |
tailMap
abstract fun tailMap(
: K,
: Boolean
): NavigableMap<K, V>
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 |
K: low endpoint of the keys in the returned map |
inclusive |
Boolean: true if the low endpoint is to be included in the returned view |
| Return | |
|---|---|
NavigableMap<K, V> |
a view of the portion of this map whose keys are greater than (or equal to, if inclusive is true) fromKey |
| Exceptions | |
|---|---|
java.lang.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. |
java.lang.NullPointerException |
if fromKey is null and this map does not permit null keys |
java.lang.IllegalArgumentException |
if this map itself has a restricted range, and fromKey lies outside the bounds of the range |
tailMap
abstract fun tailMap(: K): SortedMap<K, V>
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).
| Parameters | |
|---|---|
fromKey |
K: low endpoint (inclusive) of the keys in the returned map |
| Return | |
|---|---|
SortedMap<K, V> |
a view of the portion of this map whose keys are greater than or equal to fromKey |
| Exceptions | |
|---|---|
java.lang.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. |
java.lang.NullPointerException |
if fromKey is null and this map does not permit null keys |
java.lang.IllegalArgumentException |
if this map itself has a restricted range, and fromKey lies outside the bounds of the range |