This documentation differs from the official API. Jadeite adds extra features to the API including: variable font sizes, constructions examples, placeholders for classes and methods, and auto-generated “See Also” links. Additionally it is missing some items found in standard Javadoc documentation, including: generics type information, “Deprecated” tags and comments, “See Also” links, along with other minor differences. Please send any questions or feedback to bam@cs.cmu.edu.


java.util
interface NavigableMap

All Superinterfaces:
Map, SortedMap
All Known Subinterfaces:
ConcurrentNavigableMap
All Known Implementing Classes:
TreeMap

Most common way to construct:

ObjectInputStream in = …;

NavigableMap r = (NavigableMap)in.readObject();

Based on 10 examples


public interface NavigableMap
extends SortedMap

A {@link SortedMap} extended with navigation methods returning the closest matches for given search targets. Methods {@code lowerEntry}, {@code floorEntry}, {@code ceilingEntry}, and {@code higherEntry} return {@code Map.Entry} objects associated with keys respectively less than, less than or equal, greater than or equal, and greater than a given key, returning {@code null} if there is no such key. Similarly, methods {@code lowerKey}, {@code floorKey}, {@code ceilingKey}, and {@code higherKey} return only the associated keys. All of these methods are designed for locating, not traversing entries.

A {@code NavigableMap} may be accessed and traversed in either ascending or descending key order. The {@code 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 {@code subMap}, {@code headMap}, and {@code tailMap} differ from the like-named {@code SortedMap} methods in accepting additional arguments describing whether lower and upper bounds are inclusive versus exclusive. Submaps of any {@code NavigableMap} must implement the {@code NavigableMap} interface.

This interface additionally defines methods {@code firstEntry}, {@code pollFirstEntry}, {@code lastEntry}, and {@code pollLastEntry} that return and/or remove the least and greatest mappings, if any exist, else returning {@code null}.

Implementations of entry-returning methods are expected to return {@code Map.Entry} pairs representing snapshots of mappings at the time they were produced, and thus generally do not support the optional {@code Entry.setValue} method. Note however that it is possible to change mappings in the associated map using method {@code put}.

Methods {@link #subMap(Object, Object) subMap(K, K)}, {@link #headMap(Object) headMap(K)}, and {@link #tailMap(Object) tailMap(K)} are specified to return {@code SortedMap} to allow existing implementations of {@code SortedMap} to be compatibly retrofitted to implement {@code NavigableMap}, but extensions and implementations of this interface are encouraged to override these methods to return {@code NavigableMap}. Similarly, {@link #keySet()} can be overriden to return {@code NavigableSet}.

This interface is a member of the Java Collections Framework.


Nested Class Summary
 
Nested classes/interfaces inherited from class java.util.Map
Map.Entry
   
Method Summary
 Map.Entry

          Returns a key-value mapping associated with the least key greater than or equal to the given key, or if there is no such key.
 Object

          Returns the least key greater than or equal to the given key, or if there is no such key.
 NavigableSet

          Returns a reverse order java.util.NavigableSet view of the keys contained in this map.
 NavigableMap

          Returns a reverse order view of the mappings contained in this map.
 Map.Entry

          Returns a key-value mapping associated with the least key in this map, or if the map is empty.
 Map.Entry

          Returns a key-value mapping associated with the greatest key less than or equal to the given key, or if there is no such key.
 Object

          Returns the greatest key less than or equal to the given key, or if there is no such key.
 SortedMap
headMap(Object toKey)

          
 NavigableMap
headMap(Object toKey, boolean inclusive)

          Returns a view of the portion of this map whose keys are less than (or equal to, if is true) .
 Map.Entry

          Returns a key-value mapping associated with the least key strictly greater than the given key, or if there is no such key.
 Object

          Returns the least key strictly greater than the given key, or if there is no such key.
 Map.Entry

          Returns a key-value mapping associated with the greatest key in this map, or if the map is empty.
 Map.Entry

          Returns a key-value mapping associated with the greatest key strictly less than the given key, or if there is no such key.
 Object

          Returns the greatest key strictly less than the given key, or if there is no such key.
 NavigableSet

          Returns a java.util.NavigableSet view of the keys contained in this map.
 Map.Entry

          Removes and returns a key-value mapping associated with the least key in this map, or if the map is empty.
 Map.Entry

          Removes and returns a key-value mapping associated with the greatest key in this map, or if the map is empty.
 NavigableMap
subMap(Object fromKey, boolean fromInclusive, Object toKey, boolean toInclusive)

          Returns a view of the portion of this map whose keys range from to .
 SortedMap
subMap(Object fromKey, Object toKey)

          
 SortedMap
tailMap(Object fromKey)

          
 NavigableMap
tailMap(Object fromKey, boolean inclusive)

          Returns a view of the portion of this map whose keys are greater than (or equal to, if is true) .
 
Methods inherited from class java.util.SortedMap
comparator, entrySet, firstKey, headMap, keySet, lastKey, subMap, tailMap, values
 
Methods inherited from class java.util.Map
clear, containsKey, containsValue, entrySet, equals, get, hashCode, isEmpty, keySet, put, putAll, remove, size, values
 

Method Detail

ceilingEntry

public Map.Entry ceilingEntry(Object key)
Returns a key-value mapping associated with the least key greater than or equal to the given key, or {@code null} if there is no such key.

Parameters:
key - the key
Returns:
an entry with the least key greater than or equal to {@code key}, or {@code null} if there is no such key

ceilingKey

public Object ceilingKey(Object key)
Returns the least key greater than or equal to the given key, or {@code null} if there is no such key.

Parameters:
key - the key
Returns:
the least key greater than or equal to {@code key}, or {@code null} if there is no such key

descendingKeySet

public NavigableSet descendingKeySet()
Returns a reverse order {@link 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 {@code remove} operation), the results of the iteration are undefined. The set supports element removal, which removes the corresponding mapping from the map, via the {@code Iterator.remove}, {@code Set.remove}, {@code removeAll}, {@code retainAll}, and {@code clear} operations. It does not support the {@code add} or {@code addAll} operations.

Returns:
a reverse order navigable set view of the keys in this map

descendingMap

public NavigableMap 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. If either map is modified while an iteration over a collection view of either map is in progress (except through the iterator's own {@code remove} operation), the results of the iteration are undefined.

The returned map has an ordering equivalent to {@link Collections#reverseOrder(Comparator) Collections.reverseOrder}(comparator()). The expression {@code m.descendingMap().descendingMap()} returns a view of {@code m} essentially equivalent to {@code m}.

Returns:
a reverse order view of this map

firstEntry

public Map.Entry firstEntry()
Returns a key-value mapping associated with the least key in this map, or {@code null} if the map is empty.

Returns:
an entry with the least key, or {@code null} if this map is empty

floorEntry

public Map.Entry floorEntry(Object key)
Returns a key-value mapping associated with the greatest key less than or equal to the given key, or {@code null} if there is no such key.

Parameters:
key - the key
Returns:
an entry with the greatest key less than or equal to {@code key}, or {@code null} if there is no such key

floorKey

public Object floorKey(Object key)
Returns the greatest key less than or equal to the given key, or {@code null} if there is no such key.

Parameters:
key - the key
Returns:
the greatest key less than or equal to {@code key}, or {@code null} if there is no such key

headMap

public SortedMap headMap(Object toKey)
{@inheritDoc}

Equivalent to {@code headMap(toKey, false)}.

Parameters:
toKey

headMap

public NavigableMap headMap(Object toKey,
                            boolean inclusive)
Returns a view of the portion of this map whose keys are less than (or equal to, if {@code inclusive} is true) {@code 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 {@code IllegalArgumentException} on an attempt to insert a key outside its range.

Parameters:
toKey - high endpoint of the keys in the returned map
inclusive - {@code 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 {@code inclusive} is true) {@code toKey}

higherEntry

public Map.Entry higherEntry(Object key)
Returns a key-value mapping associated with the least key strictly greater than the given key, or {@code null} if there is no such key.

Parameters:
key - the key
Returns:
an entry with the least key greater than {@code key}, or {@code null} if there is no such key

higherKey

public Object higherKey(Object key)
Returns the least key strictly greater than the given key, or {@code null} if there is no such key.

Parameters:
key - the key
Returns:
the least key greater than {@code key}, or {@code null} if there is no such key

lastEntry

public Map.Entry lastEntry()
Returns a key-value mapping associated with the greatest key in this map, or {@code null} if the map is empty.

Returns:
an entry with the greatest key, or {@code null} if this map is empty

lowerEntry

public Map.Entry lowerEntry(Object key)
Returns a key-value mapping associated with the greatest key strictly less than the given key, or {@code null} if there is no such key.

Parameters:
key - the key
Returns:
an entry with the greatest key less than {@code key}, or {@code null} if there is no such key

lowerKey

public Object lowerKey(Object key)
Returns the greatest key strictly less than the given key, or {@code null} if there is no such key.

Parameters:
key - the key
Returns:
the greatest key less than {@code key}, or {@code null} if there is no such key

navigableKeySet

public NavigableSet navigableKeySet()
Returns a {@link 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 {@code remove} operation), the results of the iteration are undefined. The set supports element removal, which removes the corresponding mapping from the map, via the {@code Iterator.remove}, {@code Set.remove}, {@code removeAll}, {@code retainAll}, and {@code clear} operations. It does not support the {@code add} or {@code addAll} operations.

Returns:
a navigable set view of the keys in this map

pollFirstEntry

public Map.Entry pollFirstEntry()
Removes and returns a key-value mapping associated with the least key in this map, or {@code null} if the map is empty.

Returns:
the removed first entry of this map, or {@code null} if this map is empty

pollLastEntry

public Map.Entry pollLastEntry()
Removes and returns a key-value mapping associated with the greatest key in this map, or {@code null} if the map is empty.

Returns:
the removed last entry of this map, or {@code null} if this map is empty

subMap

public NavigableMap subMap(Object fromKey,
                           boolean fromInclusive,
                           Object toKey,
                           boolean toInclusive)
Returns a view of the portion of this map whose keys range from {@code fromKey} to {@code toKey}. If {@code fromKey} and {@code toKey} are equal, the returned map is empty unless {@code fromExclusive} and {@code 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 {@code 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
fromInclusive - {@code true} if the low endpoint is to be included in the returned view
toKey - high endpoint of the keys in the returned map
toInclusive - {@code 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 {@code fromKey} to {@code toKey}

subMap

public SortedMap subMap(Object fromKey,
                        Object toKey)
{@inheritDoc}

Equivalent to {@code subMap(fromKey, true, toKey, false)}.

Parameters:
fromKey
toKey

tailMap

public SortedMap tailMap(Object fromKey)
{@inheritDoc}

Equivalent to {@code tailMap(fromKey, true)}.

Parameters:
fromKey

tailMap

public NavigableMap tailMap(Object fromKey,
                            boolean inclusive)
Returns a view of the portion of this map whose keys are greater than (or equal to, if {@code inclusive} is true) {@code 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 {@code IllegalArgumentException} on an attempt to insert a key outside its range.

Parameters:
fromKey - low endpoint of the keys in the returned map
inclusive - {@code 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 {@code inclusive} is true) {@code fromKey}


This documentation differs from the official API. Jadeite adds extra features to the API including: variable font sizes, constructions examples, placeholders for classes and methods, and auto-generated “See Also” links. Additionally it is missing some items found in standard Javadoc documentation, including: generics type information, “Deprecated” tags and comments, “See Also” links, along with other minor differences. Please send any questions or feedback to bam@cs.cmu.edu.
This page displays the Jadeite version of the documention, which is derived from the offical documentation that contains this copyright notice:
Copyright 2008 Sun Microsystems, Inc. All rights reserved. Use is subject to license terms. Also see the documentation redistribution policy.
The official Sun™ documentation can be found here at http://java.sun.com/javase/6/docs/api/.