--- jsr166/src/main/java/util/NavigableMap.java 2006/04/21 22:42:27 1.20 +++ jsr166/src/main/java/util/NavigableMap.java 2015/09/30 19:14:05 1.30 @@ -1,7 +1,7 @@ /* * Written by Doug Lea and Josh Bloch with assistance from members of JCP * JSR-166 Expert Group and released to the public domain, as explained at - * http://creativecommons.org/licenses/publicdomain + * http://creativecommons.org/publicdomain/zero/1.0/ */ package java.util; @@ -9,41 +9,54 @@ package java.util; /** * 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 + * {@link #lowerEntry}, {@link #floorEntry}, {@link #ceilingEntry}, + * and {@link #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 + * {@link #lowerKey}, {@link #floorKey}, {@link #ceilingKey}, and + * {@link #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} + * ascending or descending key order. The {@link #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. + * ones. Methods + * {@link #subMap(Object, boolean, Object, boolean) subMap(K, boolean, K, boolean)}, + * {@link #headMap(Object, boolean) headMap(K, boolean)}, and + * {@link #tailMap(Object, boolean) tailMap(K, boolean)} + * 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 + *
This interface additionally defines methods {@link #firstEntry}, + * {@link #pollFirstEntry}, {@link #lastEntry}, and + * {@link #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 + *
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 overridden to return {@link NavigableSet}. + * *
This interface is a member of the
- *
+ *
* Java Collections Framework.
*
* @author Doug Lea
@@ -206,50 +219,51 @@ public interface NavigableMap The returned map has an ordering equivalent to
+ * {@link Collections#reverseOrder(Comparator) Collections.reverseOrder}{@code (comparator())}.
+ * The expression {@code m.descendingMap().descendingMap()} returns a
+ * view of {@code m} essentially equivalent to {@code m}.
*
- * @return a navigable map view of the mappings contained in this map,
- * sorted in descending order
+ * @return a reverse order view of this map
*/
NavigableMap {@inheritDoc}
+ * Equivalent to {@code subMap(fromKey, true, toKey, false)}.
*
* @throws ClassCastException {@inheritDoc}
* @throws NullPointerException {@inheritDoc}
@@ -361,10 +374,9 @@ public interface NavigableMap {@inheritDoc}
+ * Equivalent to {@code headMap(toKey, false)}.
*
* @throws ClassCastException {@inheritDoc}
* @throws NullPointerException {@inheritDoc}
@@ -373,10 +385,9 @@ public interface NavigableMap {@inheritDoc}
+ * Equivalent to {@code tailMap(fromKey, true)}.
*
* @throws ClassCastException {@inheritDoc}
* @throws NullPointerException {@inheritDoc}