| 1 |
|
/* |
| 2 |
< |
* %W% %E% |
| 2 |
> |
* Copyright 1998-2006 Sun Microsystems, Inc. All Rights Reserved. |
| 3 |
> |
* DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER. |
| 4 |
|
* |
| 5 |
< |
* Copyright 2005 Sun Microsystems, Inc. All rights reserved. |
| 6 |
< |
* SUN PROPRIETARY/CONFIDENTIAL. Use is subject to license terms. |
| 5 |
> |
* This code is free software; you can redistribute it and/or modify it |
| 6 |
> |
* under the terms of the GNU General Public License version 2 only, as |
| 7 |
> |
* published by the Free Software Foundation. Sun designates this |
| 8 |
> |
* particular file as subject to the "Classpath" exception as provided |
| 9 |
> |
* by Sun in the LICENSE file that accompanied this code. |
| 10 |
> |
* |
| 11 |
> |
* This code is distributed in the hope that it will be useful, but WITHOUT |
| 12 |
> |
* ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or |
| 13 |
> |
* FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License |
| 14 |
> |
* version 2 for more details (a copy is included in the LICENSE file that |
| 15 |
> |
* accompanied this code). |
| 16 |
> |
* |
| 17 |
> |
* You should have received a copy of the GNU General Public License version |
| 18 |
> |
* 2 along with this work; if not, write to the Free Software Foundation, |
| 19 |
> |
* Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA. |
| 20 |
> |
* |
| 21 |
> |
* Please contact Sun Microsystems, Inc., 4150 Network Circle, Santa Clara, |
| 22 |
> |
* CA 95054 USA or visit www.sun.com if you need additional information or |
| 23 |
> |
* have any questions. |
| 24 |
|
*/ |
| 25 |
|
|
| 26 |
|
package java.util; |
| 27 |
|
|
| 28 |
|
/** |
| 29 |
< |
* This class implements the <tt>Set</tt> interface, backed by a |
| 30 |
< |
* <tt>TreeMap</tt> instance. This class guarantees that the sorted set will |
| 31 |
< |
* be in ascending element order, sorted according to the <i>natural order</i> |
| 32 |
< |
* of the elements (see <tt>Comparable</tt>), or by the comparator provided at |
| 15 |
< |
* set creation time, depending on which constructor is used.<p> |
| 29 |
> |
* A {@link NavigableSet} implementation based on a {@link TreeMap}. |
| 30 |
> |
* The elements are ordered using their {@linkplain Comparable natural |
| 31 |
> |
* ordering}, or by a {@link Comparator} provided at set creation |
| 32 |
> |
* time, depending on which constructor is used. |
| 33 |
|
* |
| 34 |
< |
* This implementation provides guaranteed log(n) time cost for the basic |
| 35 |
< |
* operations (<tt>add</tt>, <tt>remove</tt> and <tt>contains</tt>).<p> |
| 34 |
> |
* <p>This implementation provides guaranteed log(n) time cost for the basic |
| 35 |
> |
* operations ({@code add}, {@code remove} and {@code contains}). |
| 36 |
|
* |
| 37 |
< |
* Note that the ordering maintained by a set (whether or not an explicit |
| 37 |
> |
* <p>Note that the ordering maintained by a set (whether or not an explicit |
| 38 |
|
* comparator is provided) must be <i>consistent with equals</i> if it is to |
| 39 |
< |
* correctly implement the <tt>Set</tt> interface. (See <tt>Comparable</tt> |
| 40 |
< |
* or <tt>Comparator</tt> for a precise definition of <i>consistent with |
| 41 |
< |
* equals</i>.) This is so because the <tt>Set</tt> interface is defined in |
| 42 |
< |
* terms of the <tt>equals</tt> operation, but a <tt>TreeSet</tt> instance |
| 43 |
< |
* performs all key comparisons using its <tt>compareTo</tt> (or |
| 44 |
< |
* <tt>compare</tt>) method, so two keys that are deemed equal by this method |
| 39 |
> |
* correctly implement the {@code Set} interface. (See {@code Comparable} |
| 40 |
> |
* or {@code Comparator} for a precise definition of <i>consistent with |
| 41 |
> |
* equals</i>.) This is so because the {@code Set} interface is defined in |
| 42 |
> |
* terms of the {@code equals} operation, but a {@code TreeSet} instance |
| 43 |
> |
* performs all element comparisons using its {@code compareTo} (or |
| 44 |
> |
* {@code compare}) method, so two elements that are deemed equal by this method |
| 45 |
|
* are, from the standpoint of the set, equal. The behavior of a set |
| 46 |
|
* <i>is</i> well-defined even if its ordering is inconsistent with equals; it |
| 47 |
< |
* just fails to obey the general contract of the <tt>Set</tt> interface.<p> |
| 47 |
> |
* just fails to obey the general contract of the {@code Set} interface. |
| 48 |
|
* |
| 49 |
< |
* <b>Note that this implementation is not synchronized.</b> If multiple |
| 50 |
< |
* threads access a set concurrently, and at least one of the threads modifies |
| 51 |
< |
* the set, it <i>must</i> be synchronized externally. This is typically |
| 52 |
< |
* accomplished by synchronizing on some object that naturally encapsulates |
| 53 |
< |
* the set. If no such object exists, the set should be "wrapped" using the |
| 54 |
< |
* <tt>Collections.synchronizedSet</tt> method. This is best done at creation |
| 55 |
< |
* time, to prevent accidental unsynchronized access to the set: <pre> |
| 56 |
< |
* SortedSet s = Collections.synchronizedSortedSet(new TreeSet(...)); |
| 57 |
< |
* </pre><p> |
| 49 |
> |
* <p><strong>Note that this implementation is not synchronized.</strong> |
| 50 |
> |
* If multiple threads access a tree set concurrently, and at least one |
| 51 |
> |
* of the threads modifies the set, it <i>must</i> be synchronized |
| 52 |
> |
* externally. This is typically accomplished by synchronizing on some |
| 53 |
> |
* object that naturally encapsulates the set. |
| 54 |
> |
* If no such object exists, the set should be "wrapped" using the |
| 55 |
> |
* {@link Collections#synchronizedSortedSet Collections.synchronizedSortedSet} |
| 56 |
> |
* method. This is best done at creation time, to prevent accidental |
| 57 |
> |
* unsynchronized access to the set: <pre> |
| 58 |
> |
* SortedSet s = Collections.synchronizedSortedSet(new TreeSet(...));</pre> |
| 59 |
|
* |
| 60 |
< |
* The Iterators returned by this class's <tt>iterator</tt> method are |
| 60 |
> |
* <p>The iterators returned by this class's {@code iterator} method are |
| 61 |
|
* <i>fail-fast</i>: if the set is modified at any time after the iterator is |
| 62 |
< |
* created, in any way except through the iterator's own <tt>remove</tt> |
| 63 |
< |
* method, the iterator will throw a <tt>ConcurrentModificationException</tt>. |
| 62 |
> |
* created, in any way except through the iterator's own {@code remove} |
| 63 |
> |
* method, the iterator will throw a {@link ConcurrentModificationException}. |
| 64 |
|
* Thus, in the face of concurrent modification, the iterator fails quickly |
| 65 |
|
* and cleanly, rather than risking arbitrary, non-deterministic behavior at |
| 66 |
|
* an undetermined time in the future. |
| 68 |
|
* <p>Note that the fail-fast behavior of an iterator cannot be guaranteed |
| 69 |
|
* as it is, generally speaking, impossible to make any hard guarantees in the |
| 70 |
|
* presence of unsynchronized concurrent modification. Fail-fast iterators |
| 71 |
< |
* throw <tt>ConcurrentModificationException</tt> on a best-effort basis. |
| 71 |
> |
* throw {@code ConcurrentModificationException} on a best-effort basis. |
| 72 |
|
* Therefore, it would be wrong to write a program that depended on this |
| 73 |
|
* exception for its correctness: <i>the fail-fast behavior of iterators |
| 74 |
|
* should be used only to detect bugs.</i> |
| 75 |
|
* |
| 76 |
|
* <p>This class is a member of the |
| 77 |
< |
* <a href="{@docRoot}/../guide/collections/index.html"> |
| 77 |
> |
* <a href="{@docRoot}/../technotes/guides/collections/index.html"> |
| 78 |
|
* Java Collections Framework</a>. |
| 79 |
|
* |
| 80 |
+ |
* @param <E> the type of elements maintained by this set |
| 81 |
+ |
* |
| 82 |
|
* @author Josh Bloch |
| 83 |
|
* @version %I%, %G% |
| 84 |
|
* @see Collection |
| 86 |
|
* @see HashSet |
| 87 |
|
* @see Comparable |
| 88 |
|
* @see Comparator |
| 69 |
– |
* @see Collections#synchronizedSortedSet(SortedSet) |
| 89 |
|
* @see TreeMap |
| 90 |
|
* @since 1.2 |
| 91 |
|
*/ |
| 92 |
|
|
| 93 |
< |
public class TreeSet<E> |
| 75 |
< |
extends AbstractSet<E> |
| 93 |
> |
public class TreeSet<E> extends AbstractSet<E> |
| 94 |
|
implements NavigableSet<E>, Cloneable, java.io.Serializable |
| 95 |
|
{ |
| 96 |
< |
private transient NavigableMap<E,Object> m; // The backing Map |
| 96 |
> |
/** |
| 97 |
> |
* The backing map. |
| 98 |
> |
*/ |
| 99 |
> |
private transient NavigableMap<E,Object> m; |
| 100 |
|
|
| 101 |
|
// Dummy value to associate with an Object in the backing Map |
| 102 |
|
private static final Object PRESENT = new Object(); |
| 103 |
|
|
| 104 |
|
/** |
| 105 |
< |
* Constructs a set backed by the specified sorted map. |
| 105 |
> |
* Constructs a set backed by the specified navigable map. |
| 106 |
|
*/ |
| 107 |
< |
private TreeSet(NavigableMap<E,Object> m) { |
| 107 |
> |
TreeSet(NavigableMap<E,Object> m) { |
| 108 |
|
this.m = m; |
| 109 |
|
} |
| 110 |
|
|
| 111 |
|
/** |
| 112 |
< |
* Constructs a new, empty set, sorted according to the elements' natural |
| 113 |
< |
* order. All elements inserted into the set must implement the |
| 114 |
< |
* <tt>Comparable</tt> interface. Furthermore, all such elements must be |
| 115 |
< |
* <i>mutually comparable</i>: <tt>e1.compareTo(e2)</tt> must not throw a |
| 116 |
< |
* <tt>ClassCastException</tt> for any elements <tt>e1</tt> and |
| 117 |
< |
* <tt>e2</tt> in the set. If the user attempts to add an element to the |
| 118 |
< |
* set that violates this constraint (for example, the user attempts to |
| 119 |
< |
* add a string element to a set whose elements are integers), the |
| 120 |
< |
* <tt>add(Object)</tt> call will throw a <tt>ClassCastException</tt>. |
| 121 |
< |
* |
| 122 |
< |
* @see Comparable |
| 112 |
> |
* Constructs a new, empty tree set, sorted according to the |
| 113 |
> |
* natural ordering of its elements. All elements inserted into |
| 114 |
> |
* the set must implement the {@link Comparable} interface. |
| 115 |
> |
* Furthermore, all such elements must be <i>mutually |
| 116 |
> |
* comparable</i>: {@code e1.compareTo(e2)} must not throw a |
| 117 |
> |
* {@code ClassCastException} for any elements {@code e1} and |
| 118 |
> |
* {@code e2} in the set. If the user attempts to add an element |
| 119 |
> |
* to the set that violates this constraint (for example, the user |
| 120 |
> |
* attempts to add a string element to a set whose elements are |
| 121 |
> |
* integers), the {@code add} call will throw a |
| 122 |
> |
* {@code ClassCastException}. |
| 123 |
|
*/ |
| 124 |
|
public TreeSet() { |
| 125 |
|
this(new TreeMap<E,Object>()); |
| 126 |
|
} |
| 127 |
|
|
| 128 |
|
/** |
| 129 |
< |
* Constructs a new, empty set, sorted according to the specified |
| 129 |
> |
* Constructs a new, empty tree set, sorted according to the specified |
| 130 |
|
* comparator. All elements inserted into the set must be <i>mutually |
| 131 |
< |
* comparable</i> by the specified comparator: <tt>comparator.compare(e1, |
| 132 |
< |
* e2)</tt> must not throw a <tt>ClassCastException</tt> for any elements |
| 133 |
< |
* <tt>e1</tt> and <tt>e2</tt> in the set. If the user attempts to add |
| 131 |
> |
* comparable</i> by the specified comparator: {@code comparator.compare(e1, |
| 132 |
> |
* e2)} must not throw a {@code ClassCastException} for any elements |
| 133 |
> |
* {@code e1} and {@code e2} in the set. If the user attempts to add |
| 134 |
|
* an element to the set that violates this constraint, the |
| 135 |
< |
* <tt>add(Object)</tt> call will throw a <tt>ClassCastException</tt>. |
| 135 |
> |
* {@code add} call will throw a {@code ClassCastException}. |
| 136 |
|
* |
| 137 |
< |
* @param c the comparator that will be used to sort this set. A |
| 138 |
< |
* <tt>null</tt> value indicates that the elements' <i>natural |
| 139 |
< |
* ordering</i> should be used. |
| 137 |
> |
* @param comparator the comparator that will be used to order this set. |
| 138 |
> |
* If {@code null}, the {@linkplain Comparable natural |
| 139 |
> |
* ordering} of the elements will be used. |
| 140 |
|
*/ |
| 141 |
< |
public TreeSet(Comparator<? super E> c) { |
| 142 |
< |
this(new TreeMap<E,Object>(c)); |
| 141 |
> |
public TreeSet(Comparator<? super E> comparator) { |
| 142 |
> |
this(new TreeMap<E,Object>(comparator)); |
| 143 |
|
} |
| 144 |
|
|
| 145 |
|
/** |
| 146 |
< |
* Constructs a new set containing the elements in the specified |
| 147 |
< |
* collection, sorted according to the elements' <i>natural order</i>. |
| 148 |
< |
* All keys inserted into the set must implement the <tt>Comparable</tt> |
| 149 |
< |
* interface. Furthermore, all such keys must be <i>mutually |
| 150 |
< |
* comparable</i>: <tt>k1.compareTo(k2)</tt> must not throw a |
| 151 |
< |
* <tt>ClassCastException</tt> for any elements <tt>k1</tt> and |
| 152 |
< |
* <tt>k2</tt> in the set. |
| 146 |
> |
* Constructs a new tree set containing the elements in the specified |
| 147 |
> |
* collection, sorted according to the <i>natural ordering</i> of its |
| 148 |
> |
* elements. All elements inserted into the set must implement the |
| 149 |
> |
* {@link Comparable} interface. Furthermore, all such elements must be |
| 150 |
> |
* <i>mutually comparable</i>: {@code e1.compareTo(e2)} must not throw a |
| 151 |
> |
* {@code ClassCastException} for any elements {@code e1} and |
| 152 |
> |
* {@code e2} in the set. |
| 153 |
|
* |
| 154 |
< |
* @param c The elements that will comprise the new set. |
| 155 |
< |
* |
| 156 |
< |
* @throws ClassCastException if the keys in the specified collection are |
| 157 |
< |
* not comparable, or are not mutually comparable. |
| 137 |
< |
* @throws NullPointerException if the specified collection is null. |
| 154 |
> |
* @param c collection whose elements will comprise the new set |
| 155 |
> |
* @throws ClassCastException if the elements in {@code c} are |
| 156 |
> |
* not {@link Comparable}, or are not mutually comparable |
| 157 |
> |
* @throws NullPointerException if the specified collection is null |
| 158 |
|
*/ |
| 159 |
|
public TreeSet(Collection<? extends E> c) { |
| 160 |
|
this(); |
| 162 |
|
} |
| 163 |
|
|
| 164 |
|
/** |
| 165 |
< |
* Constructs a new set containing the same elements as the specified |
| 166 |
< |
* sorted set, sorted according to the same ordering. |
| 165 |
> |
* Constructs a new tree set containing the same elements and |
| 166 |
> |
* using the same ordering as the specified sorted set. |
| 167 |
|
* |
| 168 |
< |
* @param s sorted set whose elements will comprise the new set. |
| 169 |
< |
* @throws NullPointerException if the specified sorted set is null. |
| 168 |
> |
* @param s sorted set whose elements will comprise the new set |
| 169 |
> |
* @throws NullPointerException if the specified sorted set is null |
| 170 |
|
*/ |
| 171 |
|
public TreeSet(SortedSet<E> s) { |
| 172 |
|
this(s.comparator()); |
| 174 |
|
} |
| 175 |
|
|
| 176 |
|
/** |
| 177 |
< |
* Returns an iterator over the elements in this set. The elements |
| 158 |
< |
* are returned in ascending order. |
| 177 |
> |
* Returns an iterator over the elements in this set in ascending order. |
| 178 |
|
* |
| 179 |
< |
* @return an iterator over the elements in this set. |
| 179 |
> |
* @return an iterator over the elements in this set in ascending order |
| 180 |
|
*/ |
| 181 |
|
public Iterator<E> iterator() { |
| 182 |
< |
return m.keySet().iterator(); |
| 182 |
> |
return m.navigableKeySet().iterator(); |
| 183 |
|
} |
| 184 |
|
|
| 185 |
|
/** |
| 186 |
< |
* Returns an iterator over the elements in this set. The elements |
| 168 |
< |
* are returned in descending order. |
| 186 |
> |
* Returns an iterator over the elements in this set in descending order. |
| 187 |
|
* |
| 188 |
< |
* @return an iterator over the elements in this set. |
| 188 |
> |
* @return an iterator over the elements in this set in descending order |
| 189 |
> |
* @since 1.6 |
| 190 |
|
*/ |
| 191 |
|
public Iterator<E> descendingIterator() { |
| 192 |
|
return m.descendingKeySet().iterator(); |
| 193 |
|
} |
| 194 |
|
|
| 195 |
|
/** |
| 196 |
+ |
* @since 1.6 |
| 197 |
+ |
*/ |
| 198 |
+ |
public NavigableSet<E> descendingSet() { |
| 199 |
+ |
return new TreeSet(m.descendingMap()); |
| 200 |
+ |
} |
| 201 |
+ |
|
| 202 |
+ |
/** |
| 203 |
|
* Returns the number of elements in this set (its cardinality). |
| 204 |
|
* |
| 205 |
< |
* @return the number of elements in this set (its cardinality). |
| 205 |
> |
* @return the number of elements in this set (its cardinality) |
| 206 |
|
*/ |
| 207 |
|
public int size() { |
| 208 |
|
return m.size(); |
| 209 |
|
} |
| 210 |
|
|
| 211 |
|
/** |
| 212 |
< |
* Returns <tt>true</tt> if this set contains no elements. |
| 212 |
> |
* Returns {@code true} if this set contains no elements. |
| 213 |
|
* |
| 214 |
< |
* @return <tt>true</tt> if this set contains no elements. |
| 214 |
> |
* @return {@code true} if this set contains no elements |
| 215 |
|
*/ |
| 216 |
|
public boolean isEmpty() { |
| 217 |
|
return m.isEmpty(); |
| 218 |
|
} |
| 219 |
|
|
| 220 |
|
/** |
| 221 |
< |
* Returns <tt>true</tt> if this set contains the specified element. |
| 222 |
< |
* |
| 223 |
< |
* @param o the object to be checked for containment in this set. |
| 224 |
< |
* @return <tt>true</tt> if this set contains the specified element. |
| 221 |
> |
* Returns {@code true} if this set contains the specified element. |
| 222 |
> |
* More formally, returns {@code true} if and only if this set |
| 223 |
> |
* contains an element {@code e} such that |
| 224 |
> |
* <tt>(o==null ? e==null : o.equals(e))</tt>. |
| 225 |
|
* |
| 226 |
+ |
* @param o object to be checked for containment in this set |
| 227 |
+ |
* @return {@code true} if this set contains the specified element |
| 228 |
|
* @throws ClassCastException if the specified object cannot be compared |
| 229 |
< |
* with the elements currently in the set. |
| 230 |
< |
* @throws NullPointerException if o is <tt>null</tt> and this map |
| 231 |
< |
* uses natural ordering and is non-empty, or its comparator does |
| 232 |
< |
* not tolerate <tt>null</tt> keys. |
| 229 |
> |
* with the elements currently in the set |
| 230 |
> |
* @throws NullPointerException if the specified element is null |
| 231 |
> |
* and this set uses natural ordering, or its comparator |
| 232 |
> |
* does not permit null elements |
| 233 |
|
*/ |
| 234 |
|
public boolean contains(Object o) { |
| 235 |
|
return m.containsKey(o); |
| 237 |
|
|
| 238 |
|
/** |
| 239 |
|
* Adds the specified element to this set if it is not already present. |
| 240 |
< |
* |
| 241 |
< |
* @param e element to be added to this set. |
| 242 |
< |
* @return <tt>true</tt> if the set did not already contain the specified |
| 243 |
< |
* element. |
| 244 |
< |
* |
| 240 |
> |
* More formally, adds the specified element {@code e} to this set if |
| 241 |
> |
* the set contains no element {@code e2} such that |
| 242 |
> |
* <tt>(e==null ? e2==null : e.equals(e2))</tt>. |
| 243 |
> |
* If this set already contains the element, the call leaves the set |
| 244 |
> |
* unchanged and returns {@code false}. |
| 245 |
> |
* |
| 246 |
> |
* @param e element to be added to this set |
| 247 |
> |
* @return {@code true} if this set did not already contain the specified |
| 248 |
> |
* element |
| 249 |
|
* @throws ClassCastException if the specified object cannot be compared |
| 250 |
< |
* with the elements currently in the set. |
| 251 |
< |
* @throws NullPointerException if e is <tt>null</tt> and this map |
| 252 |
< |
* uses natural ordering and is non-empty, or its comparator does |
| 253 |
< |
* not tolerate <tt>null</tt> keys. |
| 250 |
> |
* with the elements currently in this set |
| 251 |
> |
* @throws NullPointerException if the specified element is null |
| 252 |
> |
* and this set uses natural ordering, or its comparator |
| 253 |
> |
* does not permit null elements |
| 254 |
|
*/ |
| 255 |
|
public boolean add(E e) { |
| 256 |
|
return m.put(e, PRESENT)==null; |
| 258 |
|
|
| 259 |
|
/** |
| 260 |
|
* Removes the specified element from this set if it is present. |
| 261 |
+ |
* More formally, removes an element {@code e} such that |
| 262 |
+ |
* <tt>(o==null ? e==null : o.equals(e))</tt>, |
| 263 |
+ |
* if this set contains such an element. Returns {@code true} if |
| 264 |
+ |
* this set contained the element (or equivalently, if this set |
| 265 |
+ |
* changed as a result of the call). (This set will not contain the |
| 266 |
+ |
* element once the call returns.) |
| 267 |
|
* |
| 268 |
< |
* @param o object to be removed from this set, if present. |
| 269 |
< |
* @return <tt>true</tt> if the set contained the specified element. |
| 232 |
< |
* |
| 268 |
> |
* @param o object to be removed from this set, if present |
| 269 |
> |
* @return {@code true} if this set contained the specified element |
| 270 |
|
* @throws ClassCastException if the specified object cannot be compared |
| 271 |
< |
* with the elements currently in the set. |
| 272 |
< |
* @throws NullPointerException if o is <tt>null</tt> and this map |
| 273 |
< |
* uses natural ordering and is non-empty, or its comparator does |
| 274 |
< |
* not tolerate <tt>null</tt> keys. |
| 271 |
> |
* with the elements currently in this set |
| 272 |
> |
* @throws NullPointerException if the specified element is null |
| 273 |
> |
* and this set uses natural ordering, or its comparator |
| 274 |
> |
* does not permit null elements |
| 275 |
|
*/ |
| 276 |
|
public boolean remove(Object o) { |
| 277 |
|
return m.remove(o)==PRESENT; |
| 279 |
|
|
| 280 |
|
/** |
| 281 |
|
* Removes all of the elements from this set. |
| 282 |
+ |
* The set will be empty after this call returns. |
| 283 |
|
*/ |
| 284 |
|
public void clear() { |
| 285 |
|
m.clear(); |
| 288 |
|
/** |
| 289 |
|
* Adds all of the elements in the specified collection to this set. |
| 290 |
|
* |
| 291 |
< |
* @param c elements to be added |
| 292 |
< |
* @return <tt>true</tt> if this set changed as a result of the call. |
| 255 |
< |
* |
| 291 |
> |
* @param c collection containing elements to be added to this set |
| 292 |
> |
* @return {@code true} if this set changed as a result of the call |
| 293 |
|
* @throws ClassCastException if the elements provided cannot be compared |
| 294 |
< |
* with the elements currently in the set. |
| 295 |
< |
* @throws NullPointerException if the specified collection is |
| 296 |
< |
* <tt>null</tt> or if any element is <tt>null</tt> and this map |
| 297 |
< |
* uses natural ordering, or its comparator does not tolerate |
| 261 |
< |
* <tt>null</tt> keys. |
| 294 |
> |
* with the elements currently in the set |
| 295 |
> |
* @throws NullPointerException if the specified collection is null or |
| 296 |
> |
* if any element is null and this set uses natural ordering, or |
| 297 |
> |
* its comparator does not permit null elements |
| 298 |
|
*/ |
| 299 |
|
public boolean addAll(Collection<? extends E> c) { |
| 300 |
|
// Use linear-time version if applicable |
| 314 |
|
} |
| 315 |
|
|
| 316 |
|
/** |
| 317 |
< |
* Returns a view of the portion of this set whose elements range |
| 318 |
< |
* from <tt>fromElement</tt>, inclusive, to <tt>toElement</tt>, |
| 319 |
< |
* exclusive. (If <tt>fromElement</tt> and <tt>toElement</tt> are |
| 320 |
< |
* equal, the returned navigable set is empty.) The returned |
| 321 |
< |
* navigable set is backed by this set, so changes in the returned |
| 322 |
< |
* navigable set are reflected in this set, and vice-versa. The |
| 323 |
< |
* returned navigable set supports all optional Set operations.<p> |
| 324 |
< |
* |
| 325 |
< |
* The navigable set returned by this method will throw an |
| 326 |
< |
* <tt>IllegalArgumentException</tt> if the user attempts to insert an |
| 327 |
< |
* element outside the specified range.<p> |
| 328 |
< |
* |
| 329 |
< |
* Note: this method always returns a <i>half-open range</i> |
| 330 |
< |
* (which includes its low endpoint but not its high endpoint). |
| 331 |
< |
* If you need a <i>closed range</i> (which includes both |
| 332 |
< |
* endpoints), and the element type allows for calculation of the |
| 333 |
< |
* successor of a specified value, merely request the subrange |
| 334 |
< |
* from <tt>lowEndpoint</tt> to <tt>successor(highEndpoint)</tt>. |
| 335 |
< |
* For example, suppose that <tt>s</tt> is a navigable set of |
| 336 |
< |
* strings. The following idiom obtains a view containing all of |
| 337 |
< |
* the strings in <tt>s</tt> from <tt>low</tt> to <tt>high</tt>, |
| 338 |
< |
* inclusive: |
| 339 |
< |
* <pre> NavigableSet sub = s.navigableSubSet(low, high+"\0"); |
| 340 |
< |
* </pre> |
| 341 |
< |
* |
| 342 |
< |
* A similar technique can be used to generate an <i>open range</i> (which |
| 343 |
< |
* contains neither endpoint). The following idiom obtains a view |
| 344 |
< |
* containing all of the strings in <tt>s</tt> from <tt>low</tt> to |
| 345 |
< |
* <tt>high</tt>, exclusive: <pre> |
| 346 |
< |
* NavigableSet sub = s.navigableSubSet(low+"\0", high); |
| 347 |
< |
* </pre> |
| 348 |
< |
* |
| 349 |
< |
* @param fromElement low endpoint (inclusive) of the range. |
| 350 |
< |
* @param toElement high endpoint (exclusive) of the range. |
| 351 |
< |
* @return a view of the portion of this set whose elements range from |
| 352 |
< |
* <tt>fromElement</tt>, inclusive, to <tt>toElement</tt>, |
| 353 |
< |
* exclusive. |
| 354 |
< |
* @throws ClassCastException if <tt>fromElement</tt> and |
| 355 |
< |
* <tt>toElement</tt> cannot be compared to one another using |
| 356 |
< |
* this set's comparator (or, if the set has no comparator, |
| 357 |
< |
* using natural ordering). |
| 358 |
< |
* @throws IllegalArgumentException if <tt>fromElement</tt> is greater than |
| 359 |
< |
* <tt>toElement</tt>. |
| 324 |
< |
* @throws NullPointerException if <tt>fromElement</tt> or |
| 325 |
< |
* <tt>toElement</tt> is <tt>null</tt> and this set uses natural |
| 326 |
< |
* order, or its comparator does not tolerate <tt>null</tt> |
| 327 |
< |
* elements. |
| 328 |
< |
*/ |
| 329 |
< |
public NavigableSet<E> navigableSubSet(E fromElement, E toElement) { |
| 330 |
< |
return new TreeSet<E>(m.navigableSubMap(fromElement, toElement)); |
| 331 |
< |
} |
| 332 |
< |
|
| 333 |
< |
/** |
| 334 |
< |
* Returns a view of the portion of this set whose elements are |
| 335 |
< |
* strictly less than <tt>toElement</tt>. The returned navigable |
| 336 |
< |
* set is backed by this set, so changes in the returned navigable |
| 337 |
< |
* set are reflected in this set, and vice-versa. The returned |
| 338 |
< |
* navigable set supports all optional set operations.<p> |
| 339 |
< |
* |
| 340 |
< |
* The navigable set returned by this method will throw an |
| 341 |
< |
* <tt>IllegalArgumentException</tt> if the user attempts to |
| 342 |
< |
* insert an element greater than or equal to |
| 343 |
< |
* <tt>toElement</tt>.<p> |
| 344 |
< |
* |
| 345 |
< |
* Note: this method always returns a view that does not contain |
| 346 |
< |
* its (high) endpoint. If you need a view that does contain this |
| 347 |
< |
* endpoint, and the element type allows for calculation of the |
| 348 |
< |
* successor of a specified value, merely request a headSet |
| 349 |
< |
* bounded by <tt>successor(highEndpoint)</tt>. For example, |
| 350 |
< |
* suppose that <tt>s</tt> is a navigable set of strings. The |
| 351 |
< |
* following idiom obtains a view containing all of the strings in |
| 352 |
< |
* <tt>s</tt> that are less than or equal to <tt>high</tt>: |
| 353 |
< |
* <pre> NavigableSet head = s.navigableHeadSet(high+"\0");</pre> |
| 354 |
< |
* |
| 355 |
< |
* @param toElement high endpoint (exclusive) of the headSet. |
| 356 |
< |
* @return a view of the portion of this set whose elements are strictly |
| 357 |
< |
* less than <tt>toElement</tt>. |
| 358 |
< |
* @throws ClassCastException if <tt>toElement</tt> is not compatible |
| 359 |
< |
* with this set's comparator (or, if the set has no comparator, |
| 360 |
< |
* if <tt>toElement</tt> does not implement <tt>Comparable</tt>). |
| 361 |
< |
* @throws IllegalArgumentException if this set is itself a subset, |
| 362 |
< |
* and <tt>toElement</tt> is not within the |
| 363 |
< |
* specified range of the subset. |
| 364 |
< |
* @throws NullPointerException if <tt>toElement</tt> is <tt>null</tt> and |
| 365 |
< |
* this set uses natural ordering, or its comparator does |
| 366 |
< |
* not tolerate <tt>null</tt> elements. |
| 367 |
< |
*/ |
| 368 |
< |
public NavigableSet<E> navigableHeadSet(E toElement) { |
| 369 |
< |
return new TreeSet<E>(m.navigableHeadMap(toElement)); |
| 370 |
< |
} |
| 371 |
< |
|
| 372 |
< |
/** |
| 373 |
< |
* Returns a view of the portion of this set whose elements are |
| 374 |
< |
* greater than or equal to <tt>fromElement</tt>. The returned |
| 375 |
< |
* navigable set is backed by this set, so changes in the returned |
| 376 |
< |
* navigable set are reflected in this set, and vice-versa. The |
| 377 |
< |
* returned navigable set supports all optional set operations.<p> |
| 378 |
< |
* |
| 379 |
< |
* The navigable set returned by this method will throw an |
| 380 |
< |
* <tt>IllegalArgumentException</tt> if the user attempts to insert an |
| 381 |
< |
* element less than <tt>fromElement</tt>. |
| 382 |
< |
* |
| 383 |
< |
* Note: this method always returns a view that contains its (low) |
| 384 |
< |
* endpoint. If you need a view that does not contain this |
| 385 |
< |
* endpoint, and the element type allows for calculation of the |
| 386 |
< |
* successor of a specified value, merely request a tailSet |
| 387 |
< |
* bounded by <tt>successor(lowEndpoint)</tt>. For example, |
| 388 |
< |
* suppose that <tt>s</tt> is a navigable set of strings. The |
| 389 |
< |
* following idiom obtains a view containing all of the strings in |
| 390 |
< |
* <tt>s</tt> that are strictly greater than <tt>low</tt>: |
| 391 |
< |
* <pre> NavigableSet tail = s.navigableTailSet(low+"\0"); |
| 392 |
< |
* </pre> |
| 393 |
< |
* |
| 394 |
< |
* @param fromElement low endpoint (inclusive) of the tailSet. |
| 395 |
< |
* @return a view of the portion of this set whose elements are |
| 396 |
< |
* greater than or equal to <tt>fromElement</tt>. |
| 397 |
< |
* @throws ClassCastException if <tt>fromElement</tt> is not compatible |
| 398 |
< |
* with this set's comparator (or, if the set has no comparator, |
| 399 |
< |
* if <tt>fromElement</tt> does not implement <tt>Comparable</tt>). |
| 400 |
< |
* @throws IllegalArgumentException if this set is itself a subset, |
| 401 |
< |
* and <tt>fromElement</tt> is not within the |
| 402 |
< |
* specified range of the subset. |
| 403 |
< |
* @throws NullPointerException if <tt>fromElement</tt> is <tt>null</tt> |
| 404 |
< |
* and this set uses natural ordering, or its comparator does |
| 405 |
< |
* not tolerate <tt>null</tt> elements. |
| 406 |
< |
*/ |
| 407 |
< |
public NavigableSet<E> navigableTailSet(E fromElement) { |
| 408 |
< |
return new TreeSet<E>(m.navigableTailMap(fromElement)); |
| 409 |
< |
} |
| 410 |
< |
|
| 411 |
< |
|
| 412 |
< |
/** |
| 413 |
< |
* Equivalent to <tt>navigableSubSet</tt> but with a return |
| 414 |
< |
* type conforming to the <tt>SortedSet</tt> interface. |
| 415 |
< |
* @param fromElement low endpoint (inclusive) of the range. |
| 416 |
< |
* @param toElement high endpoint (exclusive) of the range. |
| 417 |
< |
* @return a view of the portion of this set whose elements range from |
| 418 |
< |
* <tt>fromElement</tt>, inclusive, to <tt>toElement</tt>, |
| 419 |
< |
* exclusive. |
| 420 |
< |
* @throws ClassCastException if <tt>fromElement</tt> and |
| 421 |
< |
* <tt>toElement</tt> cannot be compared to one another using |
| 422 |
< |
* this set's comparator (or, if the set has no comparator, |
| 423 |
< |
* using natural ordering). |
| 424 |
< |
* @throws IllegalArgumentException if <tt>fromElement</tt> is greater than |
| 425 |
< |
* <tt>toElement</tt>. |
| 426 |
< |
* @throws NullPointerException if <tt>fromElement</tt> or |
| 427 |
< |
* <tt>toElement</tt> is <tt>null</tt> and this set uses natural |
| 428 |
< |
* order, or its comparator does not tolerate <tt>null</tt> |
| 429 |
< |
* elements. |
| 317 |
> |
* @throws ClassCastException {@inheritDoc} |
| 318 |
> |
* @throws NullPointerException if {@code fromElement} or {@code toElement} |
| 319 |
> |
* is null and this set uses natural ordering, or its comparator |
| 320 |
> |
* does not permit null elements |
| 321 |
> |
* @throws IllegalArgumentException {@inheritDoc} |
| 322 |
> |
* @since 1.6 |
| 323 |
> |
*/ |
| 324 |
> |
public NavigableSet<E> subSet(E fromElement, boolean fromInclusive, |
| 325 |
> |
E toElement, boolean toInclusive) { |
| 326 |
> |
return new TreeSet<E>(m.subMap(fromElement, fromInclusive, |
| 327 |
> |
toElement, toInclusive)); |
| 328 |
> |
} |
| 329 |
> |
|
| 330 |
> |
/** |
| 331 |
> |
* @throws ClassCastException {@inheritDoc} |
| 332 |
> |
* @throws NullPointerException if {@code toElement} is null and |
| 333 |
> |
* this set uses natural ordering, or its comparator does |
| 334 |
> |
* not permit null elements |
| 335 |
> |
* @throws IllegalArgumentException {@inheritDoc} |
| 336 |
> |
* @since 1.6 |
| 337 |
> |
*/ |
| 338 |
> |
public NavigableSet<E> headSet(E toElement, boolean inclusive) { |
| 339 |
> |
return new TreeSet<E>(m.headMap(toElement, inclusive)); |
| 340 |
> |
} |
| 341 |
> |
|
| 342 |
> |
/** |
| 343 |
> |
* @throws ClassCastException {@inheritDoc} |
| 344 |
> |
* @throws NullPointerException if {@code fromElement} is null and |
| 345 |
> |
* this set uses natural ordering, or its comparator does |
| 346 |
> |
* not permit null elements |
| 347 |
> |
* @throws IllegalArgumentException {@inheritDoc} |
| 348 |
> |
* @since 1.6 |
| 349 |
> |
*/ |
| 350 |
> |
public NavigableSet<E> tailSet(E fromElement, boolean inclusive) { |
| 351 |
> |
return new TreeSet<E>(m.tailMap(fromElement, inclusive)); |
| 352 |
> |
} |
| 353 |
> |
|
| 354 |
> |
/** |
| 355 |
> |
* @throws ClassCastException {@inheritDoc} |
| 356 |
> |
* @throws NullPointerException if {@code fromElement} or |
| 357 |
> |
* {@code toElement} is null and this set uses natural ordering, |
| 358 |
> |
* or its comparator does not permit null elements |
| 359 |
> |
* @throws IllegalArgumentException {@inheritDoc} |
| 360 |
|
*/ |
| 361 |
|
public SortedSet<E> subSet(E fromElement, E toElement) { |
| 362 |
< |
return new TreeSet<E>(m.navigableSubMap(fromElement, toElement)); |
| 362 |
> |
return subSet(fromElement, true, toElement, false); |
| 363 |
|
} |
| 364 |
|
|
| 365 |
|
/** |
| 366 |
< |
* Equivalent to <tt>navigableHeadSet</tt> but with a return |
| 367 |
< |
* type conforming to the <tt>SortedSet</tt> interface. |
| 368 |
< |
* |
| 369 |
< |
* @param toElement high endpoint (exclusive) of the headSet. |
| 370 |
< |
* @return a view of the portion of this set whose elements are strictly |
| 441 |
< |
* less than <tt>toElement</tt>. |
| 442 |
< |
* @throws ClassCastException if <tt>toElement</tt> is not compatible |
| 443 |
< |
* with this set's comparator (or, if the set has no comparator, |
| 444 |
< |
* if <tt>toElement</tt> does not implement <tt>Comparable</tt>). |
| 445 |
< |
* @throws IllegalArgumentException if this set is itself a subset, |
| 446 |
< |
* and <tt>toElement</tt> is not within the |
| 447 |
< |
* specified range of the subset. |
| 448 |
< |
* @throws NullPointerException if <tt>toElement</tt> is <tt>null</tt> and |
| 449 |
< |
* this set uses natural ordering, or its comparator does |
| 450 |
< |
* not tolerate <tt>null</tt> elements. |
| 366 |
> |
* @throws ClassCastException {@inheritDoc} |
| 367 |
> |
* @throws NullPointerException if {@code toElement} is null |
| 368 |
> |
* and this set uses natural ordering, or its comparator does |
| 369 |
> |
* not permit null elements |
| 370 |
> |
* @throws IllegalArgumentException {@inheritDoc} |
| 371 |
|
*/ |
| 372 |
|
public SortedSet<E> headSet(E toElement) { |
| 373 |
< |
return new TreeSet<E>(m.navigableHeadMap(toElement)); |
| 373 |
> |
return headSet(toElement, false); |
| 374 |
|
} |
| 375 |
|
|
| 376 |
|
/** |
| 377 |
< |
* Equivalent to <tt>navigableTailSet</tt> but with a return |
| 378 |
< |
* type conforming to the <tt>SortedSet</tt> interface. |
| 379 |
< |
* @param fromElement low endpoint (inclusive) of the tailSet. |
| 380 |
< |
* @return a view of the portion of this set whose elements are |
| 381 |
< |
* greater than or equal to <tt>fromElement</tt>. |
| 462 |
< |
* @throws ClassCastException if <tt>fromElement</tt> is not compatible |
| 463 |
< |
* with this set's comparator (or, if the set has no comparator, |
| 464 |
< |
* if <tt>fromElement</tt> does not implement <tt>Comparable</tt>). |
| 465 |
< |
* @throws IllegalArgumentException if this set is itself a subset, |
| 466 |
< |
* and <tt>fromElement</tt> is not within the |
| 467 |
< |
* specified range of the subset. |
| 468 |
< |
* @throws NullPointerException if <tt>fromElement</tt> is <tt>null</tt> |
| 469 |
< |
* and this set uses natural ordering, or its comparator does |
| 470 |
< |
* not tolerate <tt>null</tt> elements. |
| 377 |
> |
* @throws ClassCastException {@inheritDoc} |
| 378 |
> |
* @throws NullPointerException if {@code fromElement} is null |
| 379 |
> |
* and this set uses natural ordering, or its comparator does |
| 380 |
> |
* not permit null elements |
| 381 |
> |
* @throws IllegalArgumentException {@inheritDoc} |
| 382 |
|
*/ |
| 383 |
|
public SortedSet<E> tailSet(E fromElement) { |
| 384 |
< |
return new TreeSet<E>(m.navigableTailMap(fromElement)); |
| 384 |
> |
return tailSet(fromElement, true); |
| 385 |
|
} |
| 386 |
|
|
| 476 |
– |
/** |
| 477 |
– |
* Returns the comparator used to order this sorted set, or <tt>null</tt> |
| 478 |
– |
* if this tree set uses its elements natural ordering. |
| 479 |
– |
* |
| 480 |
– |
* @return the comparator used to order this sorted set, or <tt>null</tt> |
| 481 |
– |
* if this tree set uses its elements natural ordering. |
| 482 |
– |
*/ |
| 387 |
|
public Comparator<? super E> comparator() { |
| 388 |
|
return m.comparator(); |
| 389 |
|
} |
| 390 |
|
|
| 391 |
|
/** |
| 392 |
< |
* Returns the first (lowest) element currently in this sorted set. |
| 489 |
< |
* |
| 490 |
< |
* @return the first (lowest) element currently in this sorted set. |
| 491 |
< |
* @throws NoSuchElementException sorted set is empty. |
| 392 |
> |
* @throws NoSuchElementException {@inheritDoc} |
| 393 |
|
*/ |
| 394 |
|
public E first() { |
| 395 |
|
return m.firstKey(); |
| 396 |
|
} |
| 397 |
|
|
| 398 |
|
/** |
| 399 |
< |
* Returns the last (highest) element currently in this sorted set. |
| 499 |
< |
* |
| 500 |
< |
* @return the last (highest) element currently in this sorted set. |
| 501 |
< |
* @throws NoSuchElementException sorted set is empty. |
| 399 |
> |
* @throws NoSuchElementException {@inheritDoc} |
| 400 |
|
*/ |
| 401 |
|
public E last() { |
| 402 |
|
return m.lastKey(); |
| 404 |
|
|
| 405 |
|
// NavigableSet API methods |
| 406 |
|
|
| 509 |
– |
|
| 407 |
|
/** |
| 408 |
< |
* Returns an element greater than or equal to the given element, or |
| 409 |
< |
* <tt>null</tt> if there is no such element. |
| 410 |
< |
* |
| 411 |
< |
* @param e the value to match |
| 412 |
< |
* @return an element greater than or equal to given element, or |
| 516 |
< |
* <tt>null</tt> if there is no such element. |
| 517 |
< |
* @throws ClassCastException if e cannot be compared with the elements |
| 518 |
< |
* currently in the set. |
| 519 |
< |
* @throws NullPointerException if e is <tt>null</tt> and this map |
| 520 |
< |
* uses natural ordering and is non-empty, or its comparator does |
| 521 |
< |
* not tolerate <tt>null</tt> keys. |
| 522 |
< |
*/ |
| 523 |
< |
public E ceiling(E e) { |
| 524 |
< |
return m.ceilingKey(e); |
| 525 |
< |
} |
| 526 |
< |
|
| 527 |
< |
/** |
| 528 |
< |
* Returns an element strictly less than the given element, or |
| 529 |
< |
* <tt>null</tt> if there is no such element. |
| 530 |
< |
* |
| 531 |
< |
* @param e the value to match |
| 532 |
< |
* @return the greatest element less than the given element, or |
| 533 |
< |
* <tt>null</tt> if there is no such element. |
| 534 |
< |
* @throws ClassCastException if e cannot be compared with the elements |
| 535 |
< |
* currently in the set. |
| 536 |
< |
* @throws NullPointerException if e is <tt>null</tt> and this map |
| 537 |
< |
* uses natural ordering and is non-empty, or its comparator does |
| 538 |
< |
* not tolerate <tt>null</tt> keys. |
| 408 |
> |
* @throws ClassCastException {@inheritDoc} |
| 409 |
> |
* @throws NullPointerException if the specified element is null |
| 410 |
> |
* and this set uses natural ordering, or its comparator |
| 411 |
> |
* does not permit null elements |
| 412 |
> |
* @since 1.6 |
| 413 |
|
*/ |
| 414 |
|
public E lower(E e) { |
| 415 |
|
return m.lowerKey(e); |
| 416 |
|
} |
| 417 |
|
|
| 418 |
|
/** |
| 419 |
< |
* Returns an element less than or equal to the given element, or |
| 420 |
< |
* <tt>null</tt> if there is no such element. |
| 421 |
< |
* |
| 422 |
< |
* @param e the value to match |
| 423 |
< |
* @return the greatest element less than or equal to given |
| 550 |
< |
* element, or <tt>null</tt> if there is no such element. |
| 551 |
< |
* @throws ClassCastException if e cannot be compared with the elements |
| 552 |
< |
* currently in the set. |
| 553 |
< |
* @throws NullPointerException if e is <tt>null</tt> and this map |
| 554 |
< |
* uses natural ordering and is non-empty, or its comparator does |
| 555 |
< |
* not tolerate <tt>null</tt> keys. |
| 419 |
> |
* @throws ClassCastException {@inheritDoc} |
| 420 |
> |
* @throws NullPointerException if the specified element is null |
| 421 |
> |
* and this set uses natural ordering, or its comparator |
| 422 |
> |
* does not permit null elements |
| 423 |
> |
* @since 1.6 |
| 424 |
|
*/ |
| 425 |
|
public E floor(E e) { |
| 426 |
|
return m.floorKey(e); |
| 427 |
|
} |
| 428 |
|
|
| 429 |
|
/** |
| 430 |
< |
* Returns an element strictly greater than the given element, or |
| 431 |
< |
* <tt>null</tt> if there is no such element. |
| 432 |
< |
* |
| 433 |
< |
* @param e the value to match |
| 434 |
< |
* @return the least element greater than the given element, or |
| 435 |
< |
* <tt>null</tt> if there is no such element. |
| 436 |
< |
* @throws ClassCastException if e cannot be compared with the elements |
| 437 |
< |
* currently in the set. |
| 438 |
< |
* @throws NullPointerException if e is <tt>null</tt> and this map |
| 439 |
< |
* uses natural ordering and is non-empty, or its comparator does |
| 440 |
< |
* not tolerate <tt>null</tt> keys. |
| 430 |
> |
* @throws ClassCastException {@inheritDoc} |
| 431 |
> |
* @throws NullPointerException if the specified element is null |
| 432 |
> |
* and this set uses natural ordering, or its comparator |
| 433 |
> |
* does not permit null elements |
| 434 |
> |
* @since 1.6 |
| 435 |
> |
*/ |
| 436 |
> |
public E ceiling(E e) { |
| 437 |
> |
return m.ceilingKey(e); |
| 438 |
> |
} |
| 439 |
> |
|
| 440 |
> |
/** |
| 441 |
> |
* @throws ClassCastException {@inheritDoc} |
| 442 |
> |
* @throws NullPointerException if the specified element is null |
| 443 |
> |
* and this set uses natural ordering, or its comparator |
| 444 |
> |
* does not permit null elements |
| 445 |
> |
* @since 1.6 |
| 446 |
|
*/ |
| 447 |
|
public E higher(E e) { |
| 448 |
|
return m.higherKey(e); |
| 449 |
|
} |
| 450 |
|
|
| 451 |
|
/** |
| 452 |
< |
* Retrieves and removes the first (lowest) element. |
| 580 |
< |
* |
| 581 |
< |
* @return the least element, or <tt>null</tt> if empty. |
| 452 |
> |
* @since 1.6 |
| 453 |
|
*/ |
| 454 |
|
public E pollFirst() { |
| 455 |
|
Map.Entry<E,?> e = m.pollFirstEntry(); |
| 457 |
|
} |
| 458 |
|
|
| 459 |
|
/** |
| 460 |
< |
* Retrieves and removes the last (highest) element. |
| 590 |
< |
* |
| 591 |
< |
* @return the last element, or <tt>null</tt> if empty. |
| 460 |
> |
* @since 1.6 |
| 461 |
|
*/ |
| 462 |
|
public E pollLast() { |
| 463 |
|
Map.Entry<E,?> e = m.pollLastEntry(); |
| 465 |
|
} |
| 466 |
|
|
| 467 |
|
/** |
| 468 |
< |
* Returns a shallow copy of this <tt>TreeSet</tt> instance. (The elements |
| 468 |
> |
* Returns a shallow copy of this {@code TreeSet} instance. (The elements |
| 469 |
|
* themselves are not cloned.) |
| 470 |
|
* |
| 471 |
< |
* @return a shallow copy of this set. |
| 471 |
> |
* @return a shallow copy of this set |
| 472 |
|
*/ |
| 473 |
|
public Object clone() { |
| 474 |
|
TreeSet<E> clone = null; |
| 479 |
|
} |
| 480 |
|
|
| 481 |
|
clone.m = new TreeMap<E,Object>(m); |
| 613 |
– |
|
| 482 |
|
return clone; |
| 483 |
|
} |
| 484 |
|
|
| 485 |
|
/** |
| 486 |
< |
* Save the state of the <tt>TreeSet</tt> instance to a stream (that is, |
| 486 |
> |
* Save the state of the {@code TreeSet} instance to a stream (that is, |
| 487 |
|
* serialize it). |
| 488 |
|
* |
| 489 |
|
* @serialData Emits the comparator used to order this set, or |
| 490 |
< |
* <tt>null</tt> if it obeys its elements' natural ordering |
| 491 |
< |
* (Object), followed by the size of the set (the number of |
| 492 |
< |
* elements it contains) (int), followed by all of its |
| 493 |
< |
* elements (each an Object) in order (as determined by the |
| 494 |
< |
* set's Comparator, or by the elements' natural ordering if |
| 490 |
> |
* {@code null} if it obeys its elements' natural ordering |
| 491 |
> |
* (Object), followed by the size of the set (the number of |
| 492 |
> |
* elements it contains) (int), followed by all of its |
| 493 |
> |
* elements (each an Object) in order (as determined by the |
| 494 |
> |
* set's Comparator, or by the elements' natural ordering if |
| 495 |
|
* the set has no Comparator). |
| 496 |
|
*/ |
| 497 |
|
private void writeObject(java.io.ObjectOutputStream s) |
| 511 |
|
} |
| 512 |
|
|
| 513 |
|
/** |
| 514 |
< |
* Reconstitute the <tt>TreeSet</tt> instance from a stream (that is, |
| 514 |
> |
* Reconstitute the {@code TreeSet} instance from a stream (that is, |
| 515 |
|
* deserialize it). |
| 516 |
|
*/ |
| 517 |
|
private void readObject(java.io.ObjectInputStream s) |
