|  | /* | 
|  | * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER. | 
|  | * | 
|  | * This code is free software; you can redistribute it and/or modify it | 
|  | * under the terms of the GNU General Public License version 2 only, as | 
|  | * published by the Free Software Foundation.  Oracle designates this | 
|  | * particular file as subject to the "Classpath" exception as provided | 
|  | * by Oracle in the LICENSE file that accompanied this code. | 
|  | * | 
|  | * This code is distributed in the hope that it will be useful, but WITHOUT | 
|  | * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or | 
|  | * FITNESS FOR A PARTICULAR PURPOSE.  See the GNU General Public License | 
|  | * version 2 for more details (a copy is included in the LICENSE file that | 
|  | * accompanied this code). | 
|  | * | 
|  | * You should have received a copy of the GNU General Public License version | 
|  | * 2 along with this work; if not, write to the Free Software Foundation, | 
|  | * Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA. | 
|  | * | 
|  | * Please contact Oracle, 500 Oracle Parkway, Redwood Shores, CA 94065 USA | 
|  | * or visit www.oracle.com if you need additional information or have any | 
|  | * questions. | 
|  | */ | 
|  |  | 
|  | /* | 
|  | * This file is available under and governed by the GNU General Public | 
|  | * License version 2 only, as published by the Free Software Foundation. | 
|  | * However, the following notice accompanied the original version of this | 
|  | * file: | 
|  | * | 
|  | * 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/publicdomain/zero/1.0/ | 
|  | */ | 
|  |  | 
|  | package java.util; | 
|  |  | 
|  | // BEGIN android-note | 
|  | // removed link to collections framework docs | 
|  | // END android-note | 
|  |  | 
|  | /** | 
|  | * A {@link SortedMap} extended with navigation methods returning the | 
|  | * closest matches for given search targets. Methods | 
|  | * {@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 | 
|  | * {@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. | 
|  | * | 
|  | * <p>A {@code NavigableMap} may be accessed and traversed in either | 
|  | * 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 | 
|  | * {@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. | 
|  | * | 
|  | * <p>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}. | 
|  | * | 
|  | * <p>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 <em>not</em> | 
|  | * support the optional {@code Entry.setValue} method. Note however | 
|  | * that it is possible to change mappings in the associated map using | 
|  | * method {@code put}. | 
|  | * | 
|  | * <p>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}. | 
|  | * | 
|  | * @author Doug Lea | 
|  | * @author Josh Bloch | 
|  | * @param <K> the type of keys maintained by this map | 
|  | * @param <V> the type of mapped values | 
|  | * @since 1.6 | 
|  | */ | 
|  | public interface NavigableMap<K,V> extends SortedMap<K,V> { | 
|  | /** | 
|  | * 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. | 
|  | * | 
|  | * @param key the key | 
|  | * @return an entry with the greatest key less than {@code key}, | 
|  | *         or {@code null} if there is no such key | 
|  | * @throws ClassCastException if the specified key cannot be compared | 
|  | *         with the keys currently in the map | 
|  | * @throws NullPointerException if the specified key is null | 
|  | *         and this map does not permit null keys | 
|  | */ | 
|  | Map.Entry<K,V> lowerEntry(K key); | 
|  |  | 
|  | /** | 
|  | * Returns the greatest key strictly less than the given key, or | 
|  | * {@code null} if there is no such key. | 
|  | * | 
|  | * @param key the key | 
|  | * @return the greatest key less than {@code key}, | 
|  | *         or {@code null} if there is no such key | 
|  | * @throws ClassCastException if the specified key cannot be compared | 
|  | *         with the keys currently in the map | 
|  | * @throws NullPointerException if the specified key is null | 
|  | *         and this map does not permit null keys | 
|  | */ | 
|  | K lowerKey(K 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. | 
|  | * | 
|  | * @param key the key | 
|  | * @return an entry with the greatest key less than or equal to | 
|  | *         {@code key}, or {@code null} if there is no such key | 
|  | * @throws ClassCastException if the specified key cannot be compared | 
|  | *         with the keys currently in the map | 
|  | * @throws NullPointerException if the specified key is null | 
|  | *         and this map does not permit null keys | 
|  | */ | 
|  | Map.Entry<K,V> floorEntry(K key); | 
|  |  | 
|  | /** | 
|  | * Returns the greatest key less than or equal to the given key, | 
|  | * or {@code null} if there is no such key. | 
|  | * | 
|  | * @param key the key | 
|  | * @return the greatest key less than or equal to {@code key}, | 
|  | *         or {@code null} if there is no such key | 
|  | * @throws ClassCastException if the specified key cannot be compared | 
|  | *         with the keys currently in the map | 
|  | * @throws NullPointerException if the specified key is null | 
|  | *         and this map does not permit null keys | 
|  | */ | 
|  | K floorKey(K 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. | 
|  | * | 
|  | * @param key the key | 
|  | * @return an entry with the least key greater than or equal to | 
|  | *         {@code key}, or {@code null} if there is no such key | 
|  | * @throws ClassCastException if the specified key cannot be compared | 
|  | *         with the keys currently in the map | 
|  | * @throws NullPointerException if the specified key is null | 
|  | *         and this map does not permit null keys | 
|  | */ | 
|  | Map.Entry<K,V> ceilingEntry(K key); | 
|  |  | 
|  | /** | 
|  | * Returns the least key greater than or equal to the given key, | 
|  | * or {@code null} if there is no such key. | 
|  | * | 
|  | * @param key the key | 
|  | * @return the least key greater than or equal to {@code key}, | 
|  | *         or {@code null} if there is no such key | 
|  | * @throws ClassCastException if the specified key cannot be compared | 
|  | *         with the keys currently in the map | 
|  | * @throws NullPointerException if the specified key is null | 
|  | *         and this map does not permit null keys | 
|  | */ | 
|  | K ceilingKey(K 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. | 
|  | * | 
|  | * @param key the key | 
|  | * @return an entry with the least key greater than {@code key}, | 
|  | *         or {@code null} if there is no such key | 
|  | * @throws ClassCastException if the specified key cannot be compared | 
|  | *         with the keys currently in the map | 
|  | * @throws NullPointerException if the specified key is null | 
|  | *         and this map does not permit null keys | 
|  | */ | 
|  | Map.Entry<K,V> higherEntry(K key); | 
|  |  | 
|  | /** | 
|  | * Returns the least key strictly greater than the given key, or | 
|  | * {@code null} if there is no such key. | 
|  | * | 
|  | * @param key the key | 
|  | * @return the least key greater than {@code key}, | 
|  | *         or {@code null} if there is no such key | 
|  | * @throws ClassCastException if the specified key cannot be compared | 
|  | *         with the keys currently in the map | 
|  | * @throws NullPointerException if the specified key is null | 
|  | *         and this map does not permit null keys | 
|  | */ | 
|  | K higherKey(K key); | 
|  |  | 
|  | /** | 
|  | * Returns a key-value mapping associated with the least | 
|  | * key in this map, or {@code null} if the map is empty. | 
|  | * | 
|  | * @return an entry with the least key, | 
|  | *         or {@code null} if this map is empty | 
|  | */ | 
|  | Map.Entry<K,V> firstEntry(); | 
|  |  | 
|  | /** | 
|  | * Returns a key-value mapping associated with the greatest | 
|  | * key in this map, or {@code null} if the map is empty. | 
|  | * | 
|  | * @return an entry with the greatest key, | 
|  | *         or {@code null} if this map is empty | 
|  | */ | 
|  | Map.Entry<K,V> lastEntry(); | 
|  |  | 
|  | /** | 
|  | * Removes and returns a key-value mapping associated with | 
|  | * the least key in this map, or {@code null} if the map is empty. | 
|  | * | 
|  | * @return the removed first entry of this map, | 
|  | *         or {@code null} if this map is empty | 
|  | */ | 
|  | Map.Entry<K,V> pollFirstEntry(); | 
|  |  | 
|  | /** | 
|  | * Removes and returns a key-value mapping associated with | 
|  | * the greatest key in this map, or {@code null} if the map is empty. | 
|  | * | 
|  | * @return the removed last entry of this map, | 
|  | *         or {@code null} if this map is empty | 
|  | */ | 
|  | Map.Entry<K,V> pollLastEntry(); | 
|  |  | 
|  | /** | 
|  | * 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. | 
|  | * | 
|  | * <p>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 reverse order view of this map | 
|  | */ | 
|  | NavigableMap<K,V> descendingMap(); | 
|  |  | 
|  | /** | 
|  | * 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. | 
|  | * | 
|  | * @return a navigable set view of the keys in this map | 
|  | */ | 
|  | NavigableSet<K> navigableKeySet(); | 
|  |  | 
|  | /** | 
|  | * 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. | 
|  | * | 
|  | * @return a reverse order navigable set view of the keys in this map | 
|  | */ | 
|  | NavigableSet<K> descendingKeySet(); | 
|  |  | 
|  | /** | 
|  | * 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 fromInclusive} and {@code toInclusive} 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. | 
|  | * | 
|  | * <p>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. | 
|  | * | 
|  | * @param fromKey low endpoint of the keys in the returned map | 
|  | * @param fromInclusive {@code true} if the low endpoint | 
|  | *        is to be included in the returned view | 
|  | * @param toKey high endpoint of the keys in the returned map | 
|  | * @param toInclusive {@code true} if the high endpoint | 
|  | *        is to be included in the returned view | 
|  | * @return a view of the portion of this map whose keys range from | 
|  | *         {@code fromKey} to {@code toKey} | 
|  | * @throws ClassCastException if {@code fromKey} and {@code toKey} | 
|  | *         cannot be compared to one another using this map's comparator | 
|  | *         (or, if the map has no comparator, using natural ordering). | 
|  | *         Implementations may, but are not required to, throw this | 
|  | *         exception if {@code fromKey} or {@code toKey} | 
|  | *         cannot be compared to keys currently in the map. | 
|  | * @throws NullPointerException if {@code fromKey} or {@code toKey} | 
|  | *         is null and this map does not permit null keys | 
|  | * @throws IllegalArgumentException if {@code fromKey} is greater than | 
|  | *         {@code toKey}; or if this map itself has a restricted | 
|  | *         range, and {@code fromKey} or {@code toKey} lies | 
|  | *         outside the bounds of the range | 
|  | */ | 
|  | NavigableMap<K,V> subMap(K fromKey, boolean fromInclusive, | 
|  | K toKey,   boolean toInclusive); | 
|  |  | 
|  | /** | 
|  | * 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. | 
|  | * | 
|  | * <p>The returned map will throw an {@code IllegalArgumentException} | 
|  | * on an attempt to insert a key outside its range. | 
|  | * | 
|  | * @param toKey high endpoint of the keys in the returned map | 
|  | * @param inclusive {@code true} if the high endpoint | 
|  | *        is to be included in the returned view | 
|  | * @return a view of the portion of this map whose keys are less than | 
|  | *         (or equal to, if {@code inclusive} is true) {@code toKey} | 
|  | * @throws ClassCastException if {@code toKey} is not compatible | 
|  | *         with this map's comparator (or, if the map has no comparator, | 
|  | *         if {@code toKey} does not implement {@link Comparable}). | 
|  | *         Implementations may, but are not required to, throw this | 
|  | *         exception if {@code toKey} cannot be compared to keys | 
|  | *         currently in the map. | 
|  | * @throws NullPointerException if {@code toKey} is null | 
|  | *         and this map does not permit null keys | 
|  | * @throws IllegalArgumentException if this map itself has a | 
|  | *         restricted range, and {@code toKey} lies outside the | 
|  | *         bounds of the range | 
|  | */ | 
|  | NavigableMap<K,V> headMap(K toKey, 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. | 
|  | * | 
|  | * <p>The returned map will throw an {@code IllegalArgumentException} | 
|  | * on an attempt to insert a key outside its range. | 
|  | * | 
|  | * @param fromKey low endpoint of the keys in the returned map | 
|  | * @param inclusive {@code true} if the low endpoint | 
|  | *        is to be included in the returned view | 
|  | * @return a view of the portion of this map whose keys are greater than | 
|  | *         (or equal to, if {@code inclusive} is true) {@code fromKey} | 
|  | * @throws ClassCastException if {@code fromKey} is not compatible | 
|  | *         with this map's comparator (or, if the map has no comparator, | 
|  | *         if {@code fromKey} does not implement {@link Comparable}). | 
|  | *         Implementations may, but are not required to, throw this | 
|  | *         exception if {@code fromKey} cannot be compared to keys | 
|  | *         currently in the map. | 
|  | * @throws NullPointerException if {@code fromKey} is null | 
|  | *         and this map does not permit null keys | 
|  | * @throws IllegalArgumentException if this map itself has a | 
|  | *         restricted range, and {@code fromKey} lies outside the | 
|  | *         bounds of the range | 
|  | */ | 
|  | NavigableMap<K,V> tailMap(K fromKey, boolean inclusive); | 
|  |  | 
|  | /** | 
|  | * {@inheritDoc} | 
|  | * | 
|  | * <p>Equivalent to {@code subMap(fromKey, true, toKey, false)}. | 
|  | * | 
|  | * @throws ClassCastException       {@inheritDoc} | 
|  | * @throws NullPointerException     {@inheritDoc} | 
|  | * @throws IllegalArgumentException {@inheritDoc} | 
|  | */ | 
|  | SortedMap<K,V> subMap(K fromKey, K toKey); | 
|  |  | 
|  | /** | 
|  | * {@inheritDoc} | 
|  | * | 
|  | * <p>Equivalent to {@code headMap(toKey, false)}. | 
|  | * | 
|  | * @throws ClassCastException       {@inheritDoc} | 
|  | * @throws NullPointerException     {@inheritDoc} | 
|  | * @throws IllegalArgumentException {@inheritDoc} | 
|  | */ | 
|  | SortedMap<K,V> headMap(K toKey); | 
|  |  | 
|  | /** | 
|  | * {@inheritDoc} | 
|  | * | 
|  | * <p>Equivalent to {@code tailMap(fromKey, true)}. | 
|  | * | 
|  | * @throws ClassCastException       {@inheritDoc} | 
|  | * @throws NullPointerException     {@inheritDoc} | 
|  | * @throws IllegalArgumentException {@inheritDoc} | 
|  | */ | 
|  | SortedMap<K,V> tailMap(K fromKey); | 
|  | } |