| /* |
| * Copyright (c) 1998, 2006, Oracle and/or its affiliates. All rights reserved. |
| * 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. |
| * |
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| */ |
| |
| package java.util; |
| |
| /** |
| * A {@link Map} that further provides a <i>total ordering</i> on its keys. |
| * The map is ordered according to the {@linkplain Comparable natural |
| * ordering} of its keys, or by a {@link Comparator} typically |
| * provided at sorted map creation time. This order is reflected when |
| * iterating over the sorted map's collection views (returned by the |
| * <tt>entrySet</tt>, <tt>keySet</tt> and <tt>values</tt> methods). |
| * Several additional operations are provided to take advantage of the |
| * ordering. (This interface is the map analogue of {@link |
| * SortedSet}.) |
| * |
| * <p>All keys inserted into a sorted map must implement the <tt>Comparable</tt> |
| * interface (or be accepted by the specified comparator). Furthermore, all |
| * such keys must be <i>mutually comparable</i>: <tt>k1.compareTo(k2)</tt> (or |
| * <tt>comparator.compare(k1, k2)</tt>) must not throw a |
| * <tt>ClassCastException</tt> for any keys <tt>k1</tt> and <tt>k2</tt> in |
| * the sorted map. Attempts to violate this restriction will cause the |
| * offending method or constructor invocation to throw a |
| * <tt>ClassCastException</tt>. |
| * |
| * <p>Note that the ordering maintained by a sorted map (whether or not an |
| * explicit comparator is provided) must be <i>consistent with equals</i> if |
| * the sorted map is to correctly implement the <tt>Map</tt> interface. (See |
| * the <tt>Comparable</tt> interface or <tt>Comparator</tt> interface for a |
| * precise definition of <i>consistent with equals</i>.) This is so because |
| * the <tt>Map</tt> interface is defined in terms of the <tt>equals</tt> |
| * operation, but a sorted map performs all key comparisons using its |
| * <tt>compareTo</tt> (or <tt>compare</tt>) method, so two keys that are |
| * deemed equal by this method are, from the standpoint of the sorted map, |
| * equal. The behavior of a tree map <i>is</i> well-defined even if its |
| * ordering is inconsistent with equals; it just fails to obey the general |
| * contract of the <tt>Map</tt> interface. |
| * |
| * <p>All general-purpose sorted map implementation classes should |
| * provide four "standard" constructors: 1) A void (no arguments) |
| * constructor, which creates an empty sorted map sorted according to |
| * the natural ordering of its keys. 2) A constructor with a |
| * single argument of type <tt>Comparator</tt>, which creates an empty |
| * sorted map sorted according to the specified comparator. 3) A |
| * constructor with a single argument of type <tt>Map</tt>, which |
| * creates a new map with the same key-value mappings as its argument, |
| * sorted according to the keys' natural ordering. 4) A constructor |
| * with a single argument of type <tt>SortedMap</tt>, |
| * which creates a new sorted map with the same key-value mappings and |
| * the same ordering as the input sorted map. There is no way to |
| * enforce this recommendation, as interfaces cannot contain |
| * constructors. |
| * |
| * <p>Note: several methods return submaps with restricted key ranges. |
| * Such ranges are <i>half-open</i>, that is, they include their low |
| * endpoint but not their high endpoint (where applicable). If you need a |
| * <i>closed range</i> (which includes both endpoints), and the key type |
| * allows for calculation of the successor of a given key, merely request |
| * the subrange from <tt>lowEndpoint</tt> to |
| * <tt>successor(highEndpoint)</tt>. For example, suppose that <tt>m</tt> |
| * is a map whose keys are strings. The following idiom obtains a view |
| * containing all of the key-value mappings in <tt>m</tt> whose keys are |
| * between <tt>low</tt> and <tt>high</tt>, inclusive:<pre> |
| * SortedMap<String, V> sub = m.subMap(low, high+"\0");</pre> |
| * |
| * A similar technique can be used to generate an <i>open range</i> |
| * (which contains neither endpoint). The following idiom obtains a |
| * view containing all of the key-value mappings in <tt>m</tt> whose keys |
| * are between <tt>low</tt> and <tt>high</tt>, exclusive:<pre> |
| * SortedMap<String, V> sub = m.subMap(low+"\0", high);</pre> |
| * |
| * <p>This interface is a member of the |
| * <a href="{@docRoot}/../technotes/guides/collections/index.html"> |
| * Java Collections Framework</a>. |
| * |
| * @param <K> the type of keys maintained by this map |
| * @param <V> the type of mapped values |
| * |
| * @author Josh Bloch |
| * @see Map |
| * @see TreeMap |
| * @see SortedSet |
| * @see Comparator |
| * @see Comparable |
| * @see Collection |
| * @see ClassCastException |
| * @since 1.2 |
| */ |
| |
| public interface SortedMap<K,V> extends Map<K,V> { |
| /** |
| * Returns the comparator used to order the keys in this map, or |
| * <tt>null</tt> if this map uses the {@linkplain Comparable |
| * natural ordering} of its keys. |
| * |
| * @return the comparator used to order the keys in this map, |
| * or <tt>null</tt> if this map uses the natural ordering |
| * of its keys |
| */ |
| Comparator<? super K> comparator(); |
| |
| /** |
| * Returns a view of the portion of this map whose keys range from |
| * <tt>fromKey</tt>, inclusive, to <tt>toKey</tt>, exclusive. (If |
| * <tt>fromKey</tt> and <tt>toKey</tt> are equal, the returned map |
| * is empty.) 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 <tt>IllegalArgumentException</tt> |
| * on an attempt to insert a key outside its range. |
| * |
| * @param fromKey low endpoint (inclusive) of the keys in the returned map |
| * @param toKey high endpoint (exclusive) of the keys in the returned map |
| * @return a view of the portion of this map whose keys range from |
| * <tt>fromKey</tt>, inclusive, to <tt>toKey</tt>, exclusive |
| * @throws ClassCastException if <tt>fromKey</tt> and <tt>toKey</tt> |
| * 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 <tt>fromKey</tt> or <tt>toKey</tt> |
| * cannot be compared to keys currently in the map. |
| * @throws NullPointerException if <tt>fromKey</tt> or <tt>toKey</tt> |
| * is null and this map does not permit null keys |
| * @throws IllegalArgumentException if <tt>fromKey</tt> is greater than |
| * <tt>toKey</tt>; or if this map itself has a restricted |
| * range, and <tt>fromKey</tt> or <tt>toKey</tt> lies |
| * outside the bounds of the range |
| */ |
| SortedMap<K,V> subMap(K fromKey, K toKey); |
| |
| /** |
| * Returns a view of the portion of this map whose keys are |
| * strictly less than <tt>toKey</tt>. 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 <tt>IllegalArgumentException</tt> |
| * on an attempt to insert a key outside its range. |
| * |
| * @param toKey high endpoint (exclusive) of the keys in the returned map |
| * @return a view of the portion of this map whose keys are strictly |
| * less than <tt>toKey</tt> |
| * @throws ClassCastException if <tt>toKey</tt> is not compatible |
| * with this map's comparator (or, if the map has no comparator, |
| * if <tt>toKey</tt> does not implement {@link Comparable}). |
| * Implementations may, but are not required to, throw this |
| * exception if <tt>toKey</tt> cannot be compared to keys |
| * currently in the map. |
| * @throws NullPointerException if <tt>toKey</tt> is null and |
| * this map does not permit null keys |
| * @throws IllegalArgumentException if this map itself has a |
| * restricted range, and <tt>toKey</tt> lies outside the |
| * bounds of the range |
| */ |
| SortedMap<K,V> headMap(K toKey); |
| |
| /** |
| * Returns a view of the portion of this map whose keys are |
| * greater than or equal to <tt>fromKey</tt>. 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 <tt>IllegalArgumentException</tt> |
| * on an attempt to insert a key outside its range. |
| * |
| * @param fromKey low endpoint (inclusive) of the keys in the returned map |
| * @return a view of the portion of this map whose keys are greater |
| * than or equal to <tt>fromKey</tt> |
| * @throws ClassCastException if <tt>fromKey</tt> is not compatible |
| * with this map's comparator (or, if the map has no comparator, |
| * if <tt>fromKey</tt> does not implement {@link Comparable}). |
| * Implementations may, but are not required to, throw this |
| * exception if <tt>fromKey</tt> cannot be compared to keys |
| * currently in the map. |
| * @throws NullPointerException if <tt>fromKey</tt> is null and |
| * this map does not permit null keys |
| * @throws IllegalArgumentException if this map itself has a |
| * restricted range, and <tt>fromKey</tt> lies outside the |
| * bounds of the range |
| */ |
| SortedMap<K,V> tailMap(K fromKey); |
| |
| /** |
| * Returns the first (lowest) key currently in this map. |
| * |
| * @return the first (lowest) key currently in this map |
| * @throws NoSuchElementException if this map is empty |
| */ |
| K firstKey(); |
| |
| /** |
| * Returns the last (highest) key currently in this map. |
| * |
| * @return the last (highest) key currently in this map |
| * @throws NoSuchElementException if this map is empty |
| */ |
| K lastKey(); |
| |
| /** |
| * Returns a {@link Set} 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 <tt>remove</tt> operation), the results of |
| * the iteration are undefined. The set supports element removal, |
| * which removes the corresponding mapping from the map, via the |
| * <tt>Iterator.remove</tt>, <tt>Set.remove</tt>, |
| * <tt>removeAll</tt>, <tt>retainAll</tt>, and <tt>clear</tt> |
| * operations. It does not support the <tt>add</tt> or <tt>addAll</tt> |
| * operations. |
| * |
| * @return a set view of the keys contained in this map, sorted in |
| * ascending order |
| */ |
| Set<K> keySet(); |
| |
| /** |
| * Returns a {@link Collection} view of the values contained in this map. |
| * The collection's iterator returns the values in ascending order |
| * of the corresponding keys. |
| * The collection is backed by the map, so changes to the map are |
| * reflected in the collection, and vice-versa. If the map is |
| * modified while an iteration over the collection is in progress |
| * (except through the iterator's own <tt>remove</tt> operation), |
| * the results of the iteration are undefined. The collection |
| * supports element removal, which removes the corresponding |
| * mapping from the map, via the <tt>Iterator.remove</tt>, |
| * <tt>Collection.remove</tt>, <tt>removeAll</tt>, |
| * <tt>retainAll</tt> and <tt>clear</tt> operations. It does not |
| * support the <tt>add</tt> or <tt>addAll</tt> operations. |
| * |
| * @return a collection view of the values contained in this map, |
| * sorted in ascending key order |
| */ |
| Collection<V> values(); |
| |
| /** |
| * Returns a {@link Set} view of the mappings contained in this map. |
| * The set's iterator returns the entries in ascending key 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 <tt>remove</tt> operation, or through the |
| * <tt>setValue</tt> operation on a map entry returned by the |
| * iterator) the results of the iteration are undefined. The set |
| * supports element removal, which removes the corresponding |
| * mapping from the map, via the <tt>Iterator.remove</tt>, |
| * <tt>Set.remove</tt>, <tt>removeAll</tt>, <tt>retainAll</tt> and |
| * <tt>clear</tt> operations. It does not support the |
| * <tt>add</tt> or <tt>addAll</tt> operations. |
| * |
| * @return a set view of the mappings contained in this map, |
| * sorted in ascending key order |
| */ |
| Set<Map.Entry<K, V>> entrySet(); |
| } |
