Interface NavigableMap<K,V>

All Superinterfaces:

Map<K,V>, SortedMap<K,V>

All Known Implementing Classes:

TreeMap

public interface NavigableMap<K,V>
extends SortedMap<K,V>

NavigableMap is a SortedMap with navigation methods answering the closest matches for specified item.

Type parameter K: the type of key Type parameter V: the type of value

Since

1.6

Nested Class Summary

Nested classes/interfaces inherited from interface Map

Map.Entry<K,V>

Method Summary

Modifier and Type	Method	Description
Map.Entry<K,V>	ceilingEntry(K key)	Answers an entry related with the smallest key greater than or equal to the specified key, or null if no such key.
K	ceilingKey(K key)	Answers the smallest key greater than or equal to the specified key, or null if no such key.
NavigableSet<K>	descendingKeySet()	Answers a NavigableSet view of the keys in descending order.
NavigableMap<K,V>	descendingMap()	Answers a reverse order view of the map.
Map.Entry<K,V>	firstEntry()	Answers the entry with the smallest key, or null if the map is empty.
Map.Entry<K,V>	floorEntry(K key)	Answers an entry related with the biggest key less than or equal to the specified key, or null if no such key.
K	floorKey(K key)	Answers the biggest key less than or equal to the specified key, or null if no such key.
NavigableMap<K,V>	headMap(K endKey, boolean inclusive)	Answers a view of the head of the map whose keys are smaller than (or equal to, depends on inclusive argument) endKey.
Map.Entry<K,V>	higherEntry(K key)	Answers an entry related with the smallest key greater than the specified key, or null if no such key.
K	higherKey(K key)	Answers the smallest key greater than the specified key, or null if no such key.
Map.Entry<K,V>	lastEntry()	Answers the entry with the biggest key, or null if the map is empty.
Map.Entry<K,V>	lowerEntry(K key)	Answers an entry related with the biggest key less than the specified key, or null if no such key.
K	lowerKey(K key)	Answers the biggest key less than the specified key, or null if no such key.
NavigableSet<K>	navigableKeySet()	Answers a NavigableSet view of the keys in ascending order.
Map.Entry<K,V>	pollFirstEntry()	Deletes and answers the entry with the smallest key, or null if the map is empty.
Map.Entry<K,V>	pollLastEntry()	Deletes and answers the entry with the biggest key, or null if the map is empty.
NavigableMap<K,V>	subMap(K startKey, boolean startInclusive, K endKey, boolean endInclusive)	Answers a view of part of the map whose keys is from startKey to endKey.
NavigableMap<K,V>	tailMap(K startKey, boolean inclusive)	Answers a view of the tail of the map whose keys are bigger than (or equal to, depends on inclusive argument) startKey.

Methods inherited from interface Map

clear, containsKey, containsValue, entrySet, equals, get, hashCode, isEmpty, keySet, put, putAll, remove, size, values

Methods inherited from interface SortedMap

comparator, firstKey, headMap, lastKey, subMap, tailMap

Method Details

firstEntry

Map.Entry<K,V> firstEntry()

Answers the entry with the smallest key, or null if the map is empty.

Returns

the entry with the smallest key, or null if the map is empty

lastEntry

Map.Entry<K,V> lastEntry()

Answers the entry with the biggest key, or null if the map is empty.

Returns

the entry with the biggest key, or null if the map is empty

pollFirstEntry

Map.Entry<K,V> pollFirstEntry()

Deletes and answers the entry with the smallest key, or null if the map is empty.

Returns

the entry with the smallest key, or null if the map is empty

pollLastEntry

Map.Entry<K,V> pollLastEntry()

Deletes and answers the entry with the biggest key, or null if the map is empty.

Returns

the entry with the biggest key, or null if the map is empty

ceilingEntry

Map.Entry<K,V> ceilingEntry(K key)

Answers an entry related with the smallest key greater than or equal to the specified key, or null if no such key.

Parameters

• key: the key

Returns

the entry, or null if no such key

Throws

• ClassCastException: if the key cannot be compared with the keys in the map

• NullPointerException: if the key is null and the map can not contain null key

ceilingKey

K ceilingKey(K key)

Answers the smallest key greater than or equal to the specified key, or null if no such key.

Parameters

• key: the key

Returns

Returns:

the smallest key greater than or equal to key, or null if no such key

Throws

• ClassCastException: if the key cannot be compared with the keys in the map

• NullPointerException: if the key is null and the map can not contain null key

higherEntry

Map.Entry<K,V> higherEntry(K key)

Answers an entry related with the smallest key greater than the specified key, or null if no such key.

Parameters

• key: the key

Returns

the entry, or null if no such key

Throws

• ClassCastException: if the key cannot be compared with the keys in the map

• NullPointerException: if the key is null and the map can not contain null key

higherKey

K higherKey(K key)

Answers the smallest key greater than the specified key, or null if no such key.

Parameters

• key: the key

Returns

the smallest key greater than key, or null if no such key

Throws

• ClassCastException: if the key cannot be compared with the keys in the map

• NullPointerException: if the key is null and the map can not contain null key

floorEntry

Map.Entry<K,V> floorEntry(K key)

Answers an entry related with the biggest key less than or equal to the specified key, or null if no such key.

Parameters

• key: the key

Returns

the entry, or null if no such key

Throws

• ClassCastException: if the key cannot be compared with the keys in the map

• NullPointerException: if the key is null and the map can not contain null key

floorKey

K floorKey(K key)

Answers the biggest key less than or equal to the specified key, or null if no such key.

Parameters

• key: the key

Returns

the biggest key less than or equal to key, or null if no such key

Throws

• ClassCastException: if the key cannot be compared with the keys in the map

• NullPointerException: if the key is null and the map can not contain null key

lowerEntry

Map.Entry<K,V> lowerEntry(K key)

Answers an entry related with the biggest key less than the specified key, or null if no such key.

Parameters

• key: the key

Returns

the entry, or null if no such key

Throws

• ClassCastException: if the key cannot be compared with the keys in the map

• NullPointerException: if the key is null and the map can not contain null key

lowerKey

K lowerKey(K key)

Answers the biggest key less than the specified key, or null if no such key.

Parameters

• key: the key

Returns

the biggest key less than key, or null if no such key

Throws

• ClassCastException: if the key cannot be compared with the keys in the map

• NullPointerException: if the key is null and the map can not contain null key

navigableKeySet

NavigableSet<K> navigableKeySet()

Answers a NavigableSet view of the keys in ascending order.

Returns

the navigable set view

descendingMap

NavigableMap<K,V> descendingMap()

Answers a reverse order view of the map.

Returns

the reverse order view of the map

descendingKeySet

NavigableSet<K> descendingKeySet()

Answers a NavigableSet view of the keys in descending order.

Returns

the navigable set view

subMap

NavigableMap<K,V> subMap(K startKey,
 boolean startInclusive,
 K endKey,
 boolean endInclusive)

Answers a view of part of the map whose keys is from startKey to endKey.

Parameters

• startKey: the start key

• startInclusive: true if the start key is in the returned map

• endKey: the end key

• endInclusive: true if the end key is in the returned map

Returns

the sub-map view

Throws

• ClassCastException: @exception ClassCastException when the class of the start or end key is inappropriate for this SubMap

• NullPointerException: @exception NullPointerException when the start or end key is null and this SortedMap does not support null keys

• IllegalArgumentException: when the start key is greater than the end key

headMap

NavigableMap<K,V> headMap(K endKey,
 boolean inclusive)

Answers a view of the head of the map whose keys are smaller than (or equal to, depends on inclusive argument) endKey.

Parameters

• endKey: the end key

• inclusive: true if the end key is in the returned map

Returns

the head-map view

Throws

• ClassCastException: @exception ClassCastException when the class of the end key is inappropriate for this SubMap

• NullPointerException: @exception NullPointerException when the end key is null and this SortedMap does not support null keys

• IllegalArgumentException: @exception IllegalArgumentException when the map is range-limited and end key is out of the range of the map

tailMap

NavigableMap<K,V> tailMap(K startKey,
 boolean inclusive)

Answers a view of the tail of the map whose keys are bigger than (or equal to, depends on inclusive argument) startKey.

Parameters

• startKey: the start key

• inclusive: true if the start key is in the returned map

Returns

the tail-map view

Throws

• ClassCastException: @exception ClassCastException when the class of the start key is inappropriate for this SubMap

• NullPointerException: @exception NullPointerException when the start key is null and this SortedMap does not support null keys

• IllegalArgumentException: @exception IllegalArgumentException when the map is range-limited and start key is out of the range of the map