java.util
public interface SortedMap<K,V> extends Map<K,V>
All keys entered in the map must be mutually comparable; in other words,
k1.compareTo(k2) or comparator.compare(k1, k2)
must not throw a ClassCastException. The ordering must be consistent
with equals (see {@link Comparator} for this definition), if the
map is to obey the general contract of the Map interface. If not,
the results are well-defined, but probably not what you wanted.
It is recommended that all implementing classes provide four constructors: 1) one that takes no arguments and builds an empty map sorted by natural order of the keys; 2) one that takes a Comparator for the sorting order; 3) one that takes a Map and sorts according to the natural order of its keys; and 4) one that takes a SortedMap and sorts by the same comparator. Unfortunately, the Java language does not provide a way to enforce this.
Since: 1.2
See Also: Map TreeMap SortedSet Comparable Comparator Collection ClassCastException
UNKNOWN: updated to 1.4
| Method Summary | |
|---|---|
| Comparator<? super K> | comparator()
Returns the comparator used in sorting this map, or null if it is
the keys' natural ordering.
|
| K | firstKey()
Returns the first (lowest sorted) key in the map.
|
| SortedMap<K,V> | headMap(K toKey)
Returns a view of the portion of the map strictly less than toKey. |
| K | lastKey()
Returns the last (highest sorted) key in the map.
|
| SortedMap<K,V> | subMap(K fromKey, K toKey)
Returns a view of the portion of the map greater than or equal to
fromKey, and strictly less than toKey. |
| SortedMap<K,V> | tailMap(K fromKey)
Returns a view of the portion of the map greater than or equal to
fromKey. |
Returns: the sorting comparator
Returns: the first key
Throws: NoSuchElementException if this map is empty.
The returned map throws an IllegalArgumentException any time a key is
used which is out of the range of toKey. Note that the endpoint, toKey,
is not included; if you want this value to be included, pass its successor
object in to toKey. For example, for Integers, you could request
headMap(new Integer(limit.intValue() + 1)).
Parameters: toKey the exclusive upper range of the submap
Returns: the submap
Throws: ClassCastException if toKey is not comparable to the map contents IllegalArgumentException if this is a subMap, and toKey is out of range NullPointerException if toKey is null but the map does not allow null keys
Returns: the last key
Throws: NoSuchElementException if this map is empty.
The returned map throws an IllegalArgumentException any time a key is
used which is out of the range of fromKey and toKey. Note that the
lower endpoint is included, but the upper is not; if you want to
change the inclusion or exclusion of an endpoint, pass its successor
object in instead. For example, for Integers, you could request
subMap(new Integer(lowlimit.intValue() + 1),
new Integer(highlimit.intValue() + 1)) to reverse
the inclusiveness of both endpoints.
Parameters: fromKey the inclusive lower range of the submap toKey the exclusive upper range of the submap
Returns: the submap
Throws: ClassCastException if fromKey or toKey is not comparable to the map contents IllegalArgumentException if this is a subMap, and fromKey or toKey is out of range NullPointerException if fromKey or toKey is null but the map does not allow null keys
The returned map throws an IllegalArgumentException any time a key is
used which is out of the range of fromKey. Note that the endpoint, fromKey, is
included; if you do not want this value to be included, pass its successor object in
to fromKey. For example, for Integers, you could request
tailMap(new Integer(limit.intValue() + 1)).
Parameters: fromKey the inclusive lower range of the submap
Returns: the submap
Throws: ClassCastException if fromKey is not comparable to the map contents IllegalArgumentException if this is a subMap, and fromKey is out of range NullPointerException if fromKey is null but the map does not allow null keys