1 |
dl |
1.1 |
/* |
2 |
|
|
* %W% %E% |
3 |
|
|
* |
4 |
|
|
* Copyright 2004 Sun Microsystems, Inc. All rights reserved. |
5 |
|
|
* SUN PROPRIETARY/CONFIDENTIAL. Use is subject to license terms. |
6 |
|
|
*/ |
7 |
|
|
|
8 |
|
|
package java.util; |
9 |
|
|
|
10 |
|
|
/** |
11 |
|
|
* This class implements the <tt>Set</tt> interface, backed by a |
12 |
|
|
* <tt>TreeMap</tt> instance. This class guarantees that the sorted set will |
13 |
|
|
* be in ascending element order, sorted according to the <i>natural order</i> |
14 |
|
|
* of the elements (see <tt>Comparable</tt>), or by the comparator provided at |
15 |
|
|
* set creation time, depending on which constructor is used.<p> |
16 |
|
|
* |
17 |
|
|
* This implementation provides guaranteed log(n) time cost for the basic |
18 |
|
|
* operations (<tt>add</tt>, <tt>remove</tt> and <tt>contains</tt>).<p> |
19 |
|
|
* |
20 |
|
|
* Note that the ordering maintained by a set (whether or not an explicit |
21 |
|
|
* comparator is provided) must be <i>consistent with equals</i> if it is to |
22 |
|
|
* correctly implement the <tt>Set</tt> interface. (See <tt>Comparable</tt> |
23 |
|
|
* or <tt>Comparator</tt> for a precise definition of <i>consistent with |
24 |
|
|
* equals</i>.) This is so because the <tt>Set</tt> interface is defined in |
25 |
|
|
* terms of the <tt>equals</tt> operation, but a <tt>TreeSet</tt> instance |
26 |
|
|
* performs all key comparisons using its <tt>compareTo</tt> (or |
27 |
|
|
* <tt>compare</tt>) method, so two keys that are deemed equal by this method |
28 |
|
|
* are, from the standpoint of the set, equal. The behavior of a set |
29 |
|
|
* <i>is</i> well-defined even if its ordering is inconsistent with equals; it |
30 |
|
|
* just fails to obey the general contract of the <tt>Set</tt> interface.<p> |
31 |
|
|
* |
32 |
|
|
* <b>Note that this implementation is not synchronized.</b> If multiple |
33 |
|
|
* threads access a set concurrently, and at least one of the threads modifies |
34 |
|
|
* the set, it <i>must</i> be synchronized externally. This is typically |
35 |
|
|
* accomplished by synchronizing on some object that naturally encapsulates |
36 |
|
|
* the set. If no such object exists, the set should be "wrapped" using the |
37 |
|
|
* <tt>Collections.synchronizedSet</tt> method. This is best done at creation |
38 |
|
|
* time, to prevent accidental unsynchronized access to the set: <pre> |
39 |
|
|
* SortedSet s = Collections.synchronizedSortedSet(new TreeSet(...)); |
40 |
|
|
* </pre><p> |
41 |
|
|
* |
42 |
|
|
* The Iterators returned by this class's <tt>iterator</tt> method are |
43 |
|
|
* <i>fail-fast</i>: if the set is modified at any time after the iterator is |
44 |
|
|
* created, in any way except through the iterator's own <tt>remove</tt> |
45 |
|
|
* method, the iterator will throw a <tt>ConcurrentModificationException</tt>. |
46 |
|
|
* Thus, in the face of concurrent modification, the iterator fails quickly |
47 |
|
|
* and cleanly, rather than risking arbitrary, non-deterministic behavior at |
48 |
|
|
* an undetermined time in the future. |
49 |
|
|
* |
50 |
|
|
* <p>Note that the fail-fast behavior of an iterator cannot be guaranteed |
51 |
|
|
* as it is, generally speaking, impossible to make any hard guarantees in the |
52 |
|
|
* presence of unsynchronized concurrent modification. Fail-fast iterators |
53 |
|
|
* throw <tt>ConcurrentModificationException</tt> on a best-effort basis. |
54 |
|
|
* Therefore, it would be wrong to write a program that depended on this |
55 |
|
|
* exception for its correctness: <i>the fail-fast behavior of iterators |
56 |
|
|
* should be used only to detect bugs.</i><p> |
57 |
|
|
* |
58 |
|
|
* This class is a member of the |
59 |
|
|
* <a href="{@docRoot}/../guide/collections/index.html"> |
60 |
|
|
* Java Collections Framework</a>. |
61 |
|
|
* |
62 |
|
|
* @author Josh Bloch |
63 |
|
|
* @version %I%, %G% |
64 |
|
|
* @see Collection |
65 |
|
|
* @see Set |
66 |
|
|
* @see HashSet |
67 |
|
|
* @see Comparable |
68 |
|
|
* @see Comparator |
69 |
|
|
* @see Collections#synchronizedSortedSet(SortedSet) |
70 |
|
|
* @see TreeMap |
71 |
|
|
* @since 1.2 |
72 |
|
|
*/ |
73 |
|
|
|
74 |
|
|
public class TreeSet<E> |
75 |
|
|
extends AbstractSet<E> |
76 |
|
|
implements NavigableSet<E>, Cloneable, java.io.Serializable |
77 |
|
|
{ |
78 |
|
|
private transient NavigableMap<E,Object> m; // The backing Map |
79 |
|
|
|
80 |
|
|
// Dummy value to associate with an Object in the backing Map |
81 |
|
|
private static final Object PRESENT = new Object(); |
82 |
|
|
|
83 |
|
|
/** |
84 |
|
|
* Constructs a set backed by the specified sorted map. |
85 |
|
|
*/ |
86 |
|
|
private TreeSet(NavigableMap<E,Object> m) { |
87 |
|
|
this.m = m; |
88 |
|
|
} |
89 |
|
|
|
90 |
|
|
/** |
91 |
|
|
* Constructs a new, empty set, sorted according to the elements' natural |
92 |
|
|
* order. All elements inserted into the set must implement the |
93 |
|
|
* <tt>Comparable</tt> interface. Furthermore, all such elements must be |
94 |
|
|
* <i>mutually comparable</i>: <tt>e1.compareTo(e2)</tt> must not throw a |
95 |
|
|
* <tt>ClassCastException</tt> for any elements <tt>e1</tt> and |
96 |
|
|
* <tt>e2</tt> in the set. If the user attempts to add an element to the |
97 |
|
|
* set that violates this constraint (for example, the user attempts to |
98 |
|
|
* add a string element to a set whose elements are integers), the |
99 |
|
|
* <tt>add(Object)</tt> call will throw a <tt>ClassCastException</tt>. |
100 |
|
|
* |
101 |
|
|
* @see Comparable |
102 |
|
|
*/ |
103 |
|
|
public TreeSet() { |
104 |
|
|
this(new TreeMap<E,Object>()); |
105 |
|
|
} |
106 |
|
|
|
107 |
|
|
/** |
108 |
|
|
* Constructs a new, empty set, sorted according to the specified |
109 |
|
|
* comparator. All elements inserted into the set must be <i>mutually |
110 |
|
|
* comparable</i> by the specified comparator: <tt>comparator.compare(e1, |
111 |
|
|
* e2)</tt> must not throw a <tt>ClassCastException</tt> for any elements |
112 |
|
|
* <tt>e1</tt> and <tt>e2</tt> in the set. If the user attempts to add |
113 |
|
|
* an element to the set that violates this constraint, the |
114 |
|
|
* <tt>add(Object)</tt> call will throw a <tt>ClassCastException</tt>. |
115 |
|
|
* |
116 |
|
|
* @param c the comparator that will be used to sort this set. A |
117 |
|
|
* <tt>null</tt> value indicates that the elements' <i>natural |
118 |
|
|
* ordering</i> should be used. |
119 |
|
|
*/ |
120 |
|
|
public TreeSet(Comparator<? super E> c) { |
121 |
|
|
this(new TreeMap<E,Object>(c)); |
122 |
|
|
} |
123 |
|
|
|
124 |
|
|
/** |
125 |
|
|
* Constructs a new set containing the elements in the specified |
126 |
|
|
* collection, sorted according to the elements' <i>natural order</i>. |
127 |
|
|
* All keys inserted into the set must implement the <tt>Comparable</tt> |
128 |
|
|
* interface. Furthermore, all such keys must be <i>mutually |
129 |
|
|
* comparable</i>: <tt>k1.compareTo(k2)</tt> must not throw a |
130 |
|
|
* <tt>ClassCastException</tt> for any elements <tt>k1</tt> and |
131 |
|
|
* <tt>k2</tt> in the set. |
132 |
|
|
* |
133 |
|
|
* @param c The elements that will comprise the new set. |
134 |
|
|
* |
135 |
|
|
* @throws ClassCastException if the keys in the specified collection are |
136 |
|
|
* not comparable, or are not mutually comparable. |
137 |
|
|
* @throws NullPointerException if the specified collection is null. |
138 |
|
|
*/ |
139 |
|
|
public TreeSet(Collection<? extends E> c) { |
140 |
|
|
this(); |
141 |
|
|
addAll(c); |
142 |
|
|
} |
143 |
|
|
|
144 |
|
|
/** |
145 |
|
|
* Constructs a new set containing the same elements as the specified |
146 |
|
|
* sorted set, sorted according to the same ordering. |
147 |
|
|
* |
148 |
|
|
* @param s sorted set whose elements will comprise the new set. |
149 |
|
|
* @throws NullPointerException if the specified sorted set is null. |
150 |
|
|
*/ |
151 |
|
|
public TreeSet(SortedSet<E> s) { |
152 |
|
|
this(s.comparator()); |
153 |
|
|
addAll(s); |
154 |
|
|
} |
155 |
|
|
|
156 |
|
|
/** |
157 |
|
|
* Returns an iterator over the elements in this set. The elements |
158 |
|
|
* are returned in ascending order. |
159 |
|
|
* |
160 |
|
|
* @return an iterator over the elements in this set. |
161 |
|
|
*/ |
162 |
|
|
public Iterator<E> iterator() { |
163 |
|
|
return m.keySet().iterator(); |
164 |
|
|
} |
165 |
|
|
|
166 |
|
|
/** |
167 |
|
|
* Returns an iterator over the elements in this set. The elements |
168 |
|
|
* are returned in descending order. |
169 |
|
|
* |
170 |
|
|
* @return an iterator over the elements in this set. |
171 |
|
|
*/ |
172 |
|
|
public Iterator<E> descendingIterator() { |
173 |
|
|
return m.descendingKeySet().iterator(); |
174 |
|
|
} |
175 |
|
|
|
176 |
|
|
/** |
177 |
|
|
* Returns the number of elements in this set (its cardinality). |
178 |
|
|
* |
179 |
|
|
* @return the number of elements in this set (its cardinality). |
180 |
|
|
*/ |
181 |
|
|
public int size() { |
182 |
|
|
return m.size(); |
183 |
|
|
} |
184 |
|
|
|
185 |
|
|
/** |
186 |
|
|
* Returns <tt>true</tt> if this set contains no elements. |
187 |
|
|
* |
188 |
|
|
* @return <tt>true</tt> if this set contains no elements. |
189 |
|
|
*/ |
190 |
|
|
public boolean isEmpty() { |
191 |
|
|
return m.isEmpty(); |
192 |
|
|
} |
193 |
|
|
|
194 |
|
|
/** |
195 |
|
|
* Returns <tt>true</tt> if this set contains the specified element. |
196 |
|
|
* |
197 |
|
|
* @param o the object to be checked for containment in this set. |
198 |
|
|
* @return <tt>true</tt> if this set contains the specified element. |
199 |
|
|
* |
200 |
|
|
* @throws ClassCastException if the specified object cannot be compared |
201 |
|
|
* with the elements currently in the set. |
202 |
dl |
1.2 |
* @throws NullPointerException if o is <tt>null</tt> and this map |
203 |
dl |
1.1 |
* uses natural ordering and is non-empty, or its comparator does |
204 |
|
|
* not tolerate <tt>null</tt> keys. |
205 |
|
|
*/ |
206 |
|
|
public boolean contains(Object o) { |
207 |
|
|
return m.containsKey(o); |
208 |
|
|
} |
209 |
|
|
|
210 |
|
|
/** |
211 |
|
|
* Adds the specified element to this set if it is not already present. |
212 |
|
|
* |
213 |
|
|
* @param o element to be added to this set. |
214 |
|
|
* @return <tt>true</tt> if the set did not already contain the specified |
215 |
|
|
* element. |
216 |
|
|
* |
217 |
|
|
* @throws ClassCastException if the specified object cannot be compared |
218 |
|
|
* with the elements currently in the set. |
219 |
dl |
1.2 |
* @throws NullPointerException if o is <tt>null</tt> and this map |
220 |
dl |
1.1 |
* uses natural ordering and is non-empty, or its comparator does |
221 |
|
|
* not tolerate <tt>null</tt> keys. |
222 |
|
|
*/ |
223 |
|
|
public boolean add(E o) { |
224 |
|
|
return m.put(o, PRESENT)==null; |
225 |
|
|
} |
226 |
|
|
|
227 |
|
|
/** |
228 |
|
|
* Removes the specified element from this set if it is present. |
229 |
|
|
* |
230 |
|
|
* @param o object to be removed from this set, if present. |
231 |
|
|
* @return <tt>true</tt> if the set contained the specified element. |
232 |
|
|
* |
233 |
|
|
* @throws ClassCastException if the specified object cannot be compared |
234 |
|
|
* with the elements currently in the set. |
235 |
dl |
1.2 |
* @throws NullPointerException if o is <tt>null</tt> and this map |
236 |
dl |
1.1 |
* uses natural ordering and is non-empty, or its comparator does |
237 |
|
|
* not tolerate <tt>null</tt> keys. |
238 |
|
|
*/ |
239 |
|
|
public boolean remove(Object o) { |
240 |
|
|
return m.remove(o)==PRESENT; |
241 |
|
|
} |
242 |
|
|
|
243 |
|
|
/** |
244 |
|
|
* Removes all of the elements from this set. |
245 |
|
|
*/ |
246 |
|
|
public void clear() { |
247 |
|
|
m.clear(); |
248 |
|
|
} |
249 |
|
|
|
250 |
|
|
/** |
251 |
|
|
* Adds all of the elements in the specified collection to this set. |
252 |
|
|
* |
253 |
|
|
* @param c elements to be added |
254 |
|
|
* @return <tt>true</tt> if this set changed as a result of the call. |
255 |
|
|
* |
256 |
|
|
* @throws ClassCastException if the elements provided cannot be compared |
257 |
|
|
* with the elements currently in the set. |
258 |
dl |
1.4 |
* @throws NullPointerException if the specified collection is |
259 |
dl |
1.1 |
* <tt>null</tt> or if any element is <tt>null</tt> and this map |
260 |
|
|
* uses natural ordering, or its comparator does not tolerate |
261 |
|
|
* <tt>null</tt> keys. |
262 |
|
|
*/ |
263 |
|
|
public boolean addAll(Collection<? extends E> c) { |
264 |
|
|
// Use linear-time version if applicable |
265 |
|
|
if (m.size()==0 && c.size() > 0 && |
266 |
|
|
c instanceof SortedSet && |
267 |
|
|
m instanceof TreeMap) { |
268 |
|
|
SortedSet<Map.Entry<E, Object>> set = (SortedSet<Map.Entry<E, Object>>) (SortedSet) c; |
269 |
|
|
TreeMap<E,Object> map = (TreeMap<E, Object>) m; |
270 |
|
|
Comparator<? super E> cc = (Comparator<E>) set.comparator(); |
271 |
|
|
Comparator<? super E> mc = map.comparator(); |
272 |
|
|
if (cc==mc || (cc != null && cc.equals(mc))) { |
273 |
|
|
map.addAllForTreeSet(set, PRESENT); |
274 |
|
|
return true; |
275 |
|
|
} |
276 |
|
|
} |
277 |
|
|
return super.addAll(c); |
278 |
|
|
} |
279 |
|
|
|
280 |
|
|
/** |
281 |
dl |
1.3 |
* Returns a view of the portion of this set whose elements range |
282 |
|
|
* from <tt>fromElement</tt>, inclusive, to <tt>toElement</tt>, |
283 |
|
|
* exclusive. (If <tt>fromElement</tt> and <tt>toElement</tt> are |
284 |
|
|
* equal, the returned navigable set is empty.) The returned |
285 |
|
|
* navigable set is backed by this set, so changes in the returned |
286 |
|
|
* navigable set are reflected in this set, and vice-versa. The |
287 |
|
|
* returned navigable set supports all optional Set operations.<p> |
288 |
dl |
1.1 |
* |
289 |
dl |
1.3 |
* The navigable set returned by this method will throw an |
290 |
dl |
1.1 |
* <tt>IllegalArgumentException</tt> if the user attempts to insert an |
291 |
|
|
* element outside the specified range.<p> |
292 |
|
|
* |
293 |
dl |
1.3 |
* Note: this method always returns a <i>half-open range</i> |
294 |
|
|
* (which includes its low endpoint but not its high endpoint). |
295 |
|
|
* If you need a <i>closed range</i> (which includes both |
296 |
|
|
* endpoints), and the element type allows for calculation of the |
297 |
|
|
* successor of a specified value, merely request the subrange |
298 |
|
|
* from <tt>lowEndpoint</tt> to <tt>successor(highEndpoint)</tt>. |
299 |
|
|
* For example, suppose that <tt>s</tt> is a navigable set of |
300 |
|
|
* strings. The following idiom obtains a view containing all of |
301 |
|
|
* the strings in <tt>s</tt> from <tt>low</tt> to <tt>high</tt>, |
302 |
dl |
1.4 |
* inclusive: |
303 |
|
|
* <pre> NavigableSet sub = s.navigableSubSet(low, high+"\0"); |
304 |
dl |
1.1 |
* </pre> |
305 |
|
|
* |
306 |
|
|
* A similar technique can be used to generate an <i>open range</i> (which |
307 |
|
|
* contains neither endpoint). The following idiom obtains a view |
308 |
|
|
* containing all of the strings in <tt>s</tt> from <tt>low</tt> to |
309 |
|
|
* <tt>high</tt>, exclusive: <pre> |
310 |
dl |
1.3 |
* NavigableSet sub = s.navigableSubSet(low+"\0", high); |
311 |
dl |
1.1 |
* </pre> |
312 |
|
|
* |
313 |
dl |
1.4 |
* @param fromElement low endpoint (inclusive) of the range. |
314 |
|
|
* @param toElement high endpoint (exclusive) of the range. |
315 |
dl |
1.1 |
* @return a view of the portion of this set whose elements range from |
316 |
|
|
* <tt>fromElement</tt>, inclusive, to <tt>toElement</tt>, |
317 |
|
|
* exclusive. |
318 |
|
|
* @throws ClassCastException if <tt>fromElement</tt> and |
319 |
|
|
* <tt>toElement</tt> cannot be compared to one another using |
320 |
|
|
* this set's comparator (or, if the set has no comparator, |
321 |
|
|
* using natural ordering). |
322 |
|
|
* @throws IllegalArgumentException if <tt>fromElement</tt> is greater than |
323 |
|
|
* <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 |
dl |
1.3 |
public NavigableSet<E> navigableSubSet(E fromElement, E toElement) { |
330 |
|
|
return new TreeSet<E>(m.navigableSubMap(fromElement, toElement)); |
331 |
dl |
1.1 |
} |
332 |
|
|
|
333 |
|
|
/** |
334 |
dl |
1.3 |
* 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 |
dl |
1.1 |
* |
355 |
|
|
* @param toElement high endpoint (exclusive) of the headSet. |
356 |
|
|
* @return a view of the portion of this set whose elements are strictly |
357 |
dl |
1.4 |
* less than <tt>toElement</tt>. |
358 |
dl |
1.1 |
* @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 |
dl |
1.4 |
* @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 |
dl |
1.1 |
* @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 |
dl |
1.3 |
public NavigableSet<E> navigableHeadSet(E toElement) { |
369 |
|
|
return new TreeSet<E>(m.navigableHeadMap(toElement)); |
370 |
dl |
1.1 |
} |
371 |
|
|
|
372 |
|
|
/** |
373 |
|
|
* Returns a view of the portion of this set whose elements are |
374 |
dl |
1.3 |
* 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 |
dl |
1.1 |
* |
379 |
dl |
1.3 |
* The navigable set returned by this method will throw an |
380 |
dl |
1.1 |
* <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 |
dl |
1.3 |
* 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 |
dl |
1.1 |
* </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 |
dl |
1.4 |
* @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 |
dl |
1.1 |
* @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 |
dl |
1.3 |
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 |
dl |
1.4 |
* @param fromElement low endpoint (inclusive) of the range. |
416 |
|
|
* @param toElement high endpoint (exclusive) of the range. |
417 |
dl |
1.3 |
* @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. |
430 |
|
|
*/ |
431 |
|
|
public SortedSet<E> subSet(E fromElement, E toElement) { |
432 |
|
|
return new TreeSet<E>(m.navigableSubMap(fromElement, toElement)); |
433 |
|
|
} |
434 |
|
|
|
435 |
|
|
/** |
436 |
|
|
* Equivalent to <tt>navigableHeadSet</tt> but with a return |
437 |
|
|
* type conforming to the <tt>SortedSet</tt> interface. |
438 |
|
|
* |
439 |
|
|
* @param toElement high endpoint (exclusive) of the headSet. |
440 |
|
|
* @return a view of the portion of this set whose elements are strictly |
441 |
dl |
1.4 |
* less than <tt>toElement</tt>. |
442 |
dl |
1.3 |
* @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 |
dl |
1.5 |
* @throws IllegalArgumentException if this set is itself a subset, |
446 |
dl |
1.4 |
* and <tt>toElement</tt> is not within the |
447 |
|
|
* specified range of the subset. |
448 |
dl |
1.3 |
* @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. |
451 |
|
|
*/ |
452 |
|
|
public SortedSet<E> headSet(E toElement) { |
453 |
|
|
return new TreeSet<E>(m.navigableHeadMap(toElement)); |
454 |
|
|
} |
455 |
|
|
|
456 |
|
|
/** |
457 |
|
|
* Equivalent to <tt>navigableTailSet</tt> but with a return |
458 |
|
|
* type conforming to the <tt>SortedSet</tt> interface. |
459 |
|
|
* @param fromElement low endpoint (inclusive) of the tailSet. |
460 |
|
|
* @return a view of the portion of this set whose elements are |
461 |
|
|
* 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 |
dl |
1.4 |
* @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 |
dl |
1.3 |
* @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. |
471 |
|
|
*/ |
472 |
|
|
public SortedSet<E> tailSet(E fromElement) { |
473 |
|
|
return new TreeSet<E>(m.navigableTailMap(fromElement)); |
474 |
dl |
1.1 |
} |
475 |
|
|
|
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 |
|
|
*/ |
483 |
|
|
public Comparator<? super E> comparator() { |
484 |
|
|
return m.comparator(); |
485 |
|
|
} |
486 |
|
|
|
487 |
|
|
/** |
488 |
|
|
* 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. |
492 |
|
|
*/ |
493 |
|
|
public E first() { |
494 |
|
|
return m.firstKey(); |
495 |
|
|
} |
496 |
|
|
|
497 |
|
|
/** |
498 |
|
|
* 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. |
502 |
|
|
*/ |
503 |
|
|
public E last() { |
504 |
|
|
return m.lastKey(); |
505 |
|
|
} |
506 |
|
|
|
507 |
|
|
// NavigableSet API methods |
508 |
|
|
|
509 |
|
|
|
510 |
|
|
/** |
511 |
|
|
* Returns an element greater than or equal to the given element, or |
512 |
|
|
* <tt>null</tt> if there is no such element. |
513 |
|
|
* |
514 |
|
|
* @param o the value to match |
515 |
|
|
* @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 o cannot be compared with the elements |
518 |
|
|
* currently in the set. |
519 |
dl |
1.2 |
* @throws NullPointerException if o is <tt>null</tt> and this map |
520 |
dl |
1.1 |
* uses natural ordering and is non-empty, or its comparator does |
521 |
|
|
* not tolerate <tt>null</tt> keys. |
522 |
|
|
*/ |
523 |
|
|
public E ceiling(E o) { |
524 |
|
|
return m.ceilingKey(o); |
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 o 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 o cannot be compared with the elements |
535 |
|
|
* currently in the set. |
536 |
dl |
1.2 |
* @throws NullPointerException if o is <tt>null</tt> and this map |
537 |
dl |
1.1 |
* uses natural ordering and is non-empty, or its comparator does |
538 |
|
|
* not tolerate <tt>null</tt> keys. |
539 |
|
|
*/ |
540 |
|
|
public E lower(E o) { |
541 |
|
|
return m.lowerKey(o); |
542 |
|
|
} |
543 |
|
|
|
544 |
|
|
/** |
545 |
|
|
* Returns an element less than or equal to the given element, or |
546 |
|
|
* <tt>null</tt> if there is no such element. |
547 |
|
|
* |
548 |
|
|
* @param o the value to match |
549 |
|
|
* @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 o cannot be compared with the elements |
552 |
|
|
* currently in the set. |
553 |
dl |
1.2 |
* @throws NullPointerException if o is <tt>null</tt> and this map |
554 |
dl |
1.1 |
* uses natural ordering and is non-empty, or its comparator does |
555 |
|
|
* not tolerate <tt>null</tt> keys. |
556 |
|
|
*/ |
557 |
|
|
public E floor(E o) { |
558 |
|
|
return m.floorKey(o); |
559 |
|
|
} |
560 |
|
|
|
561 |
|
|
/** |
562 |
|
|
* Returns an element strictly greater than the given element, or |
563 |
|
|
* <tt>null</tt> if there is no such element. |
564 |
|
|
* |
565 |
|
|
* @param o the value to match |
566 |
|
|
* @return the least element greater than the given element, or |
567 |
|
|
* <tt>null</tt> if there is no such element. |
568 |
|
|
* @throws ClassCastException if o cannot be compared with the elements |
569 |
|
|
* currently in the set. |
570 |
dl |
1.2 |
* @throws NullPointerException if o is <tt>null</tt> and this map |
571 |
dl |
1.1 |
* uses natural ordering and is non-empty, or its comparator does |
572 |
|
|
* not tolerate <tt>null</tt> keys. |
573 |
|
|
*/ |
574 |
|
|
public E higher(E o) { |
575 |
|
|
return m.higherKey(o); |
576 |
|
|
} |
577 |
|
|
|
578 |
|
|
/** |
579 |
|
|
* Retrieves and removes the first (lowest) element. |
580 |
|
|
* |
581 |
|
|
* @return the least element, or <tt>null</tt> if empty. |
582 |
|
|
*/ |
583 |
|
|
public E pollFirst() { |
584 |
|
|
Map.Entry<E,?> e = m.pollFirstEntry(); |
585 |
|
|
return (e == null)? null : e.getKey(); |
586 |
|
|
} |
587 |
|
|
|
588 |
|
|
/** |
589 |
|
|
* Retrieves and removes the last (highest) element. |
590 |
|
|
* |
591 |
|
|
* @return the last element, or <tt>null</tt> if empty. |
592 |
|
|
*/ |
593 |
|
|
public E pollLast() { |
594 |
|
|
Map.Entry<E,?> e = m.pollLastEntry(); |
595 |
|
|
return (e == null)? null : e.getKey(); |
596 |
|
|
} |
597 |
|
|
|
598 |
|
|
/** |
599 |
|
|
* Returns a shallow copy of this <tt>TreeSet</tt> instance. (The elements |
600 |
|
|
* themselves are not cloned.) |
601 |
|
|
* |
602 |
|
|
* @return a shallow copy of this set. |
603 |
|
|
*/ |
604 |
|
|
public Object clone() { |
605 |
|
|
TreeSet<E> clone = null; |
606 |
|
|
try { |
607 |
|
|
clone = (TreeSet<E>) super.clone(); |
608 |
|
|
} catch (CloneNotSupportedException e) { |
609 |
|
|
throw new InternalError(); |
610 |
|
|
} |
611 |
|
|
|
612 |
|
|
clone.m = new TreeMap<E,Object>(m); |
613 |
|
|
|
614 |
|
|
return clone; |
615 |
|
|
} |
616 |
|
|
|
617 |
|
|
/** |
618 |
|
|
* Save the state of the <tt>TreeSet</tt> instance to a stream (that is, |
619 |
|
|
* serialize it). |
620 |
|
|
* |
621 |
|
|
* @serialData Emits the comparator used to order this set, or |
622 |
|
|
* <tt>null</tt> if it obeys its elements' natural ordering |
623 |
|
|
* (Object), followed by the size of the set (the number of |
624 |
|
|
* elements it contains) (int), followed by all of its |
625 |
|
|
* elements (each an Object) in order (as determined by the |
626 |
|
|
* set's Comparator, or by the elements' natural ordering if |
627 |
|
|
* the set has no Comparator). |
628 |
|
|
*/ |
629 |
|
|
private void writeObject(java.io.ObjectOutputStream s) |
630 |
|
|
throws java.io.IOException { |
631 |
|
|
// Write out any hidden stuff |
632 |
|
|
s.defaultWriteObject(); |
633 |
|
|
|
634 |
|
|
// Write out Comparator |
635 |
|
|
s.writeObject(m.comparator()); |
636 |
|
|
|
637 |
|
|
// Write out size |
638 |
|
|
s.writeInt(m.size()); |
639 |
|
|
|
640 |
|
|
// Write out all elements in the proper order. |
641 |
|
|
for (Iterator i=m.keySet().iterator(); i.hasNext(); ) |
642 |
|
|
s.writeObject(i.next()); |
643 |
|
|
} |
644 |
|
|
|
645 |
|
|
/** |
646 |
|
|
* Reconstitute the <tt>TreeSet</tt> instance from a stream (that is, |
647 |
|
|
* deserialize it). |
648 |
|
|
*/ |
649 |
|
|
private void readObject(java.io.ObjectInputStream s) |
650 |
|
|
throws java.io.IOException, ClassNotFoundException { |
651 |
|
|
// Read in any hidden stuff |
652 |
|
|
s.defaultReadObject(); |
653 |
|
|
|
654 |
|
|
// Read in Comparator |
655 |
|
|
Comparator<E> c = (Comparator<E>) s.readObject(); |
656 |
|
|
|
657 |
|
|
// Create backing TreeMap |
658 |
|
|
TreeMap<E,Object> tm; |
659 |
|
|
if (c==null) |
660 |
|
|
tm = new TreeMap<E,Object>(); |
661 |
|
|
else |
662 |
|
|
tm = new TreeMap<E,Object>(c); |
663 |
|
|
m = tm; |
664 |
|
|
|
665 |
|
|
// Read in size |
666 |
|
|
int size = s.readInt(); |
667 |
|
|
|
668 |
|
|
tm.readTreeSet(size, s, PRESENT); |
669 |
|
|
} |
670 |
|
|
|
671 |
|
|
private static final long serialVersionUID = -2479143000061671589L; |
672 |
|
|
} |