java.util · java.base · since Java 1.6

NavigableMap

declaration

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

A SortedMap with nearest-match key/entry navigation and descending views. TreeMap is the standard implementation.

Key methods

`K ceilingKey(K k) / floorKey(K k)`	Least key >= k / greatest key <= k (null if none).
`K higherKey(K k) / lowerKey(K k)`	Strictly-greater / strictly-lesser key (null if none).
`Map.Entry<K, V> ceilingEntry(K k) / floorEntry(K k)`	Nearest entry at or beyond / at or below k.
`Map.Entry<K, V> firstEntry() / lastEntry()`	Extreme entries (null if empty).
`Map.Entry<K, V> pollFirstEntry() / pollLastEntry()`	Retrieve and remove the extreme entry.
`NavigableMap<K, V> descendingMap()`	Reverse-order view over the same mappings.
`NavigableMap<K, V> subMap(K from, boolean fromInc, K to, boolean toInc)`	Key-range view with inclusive/exclusive endpoints.