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1
7
8 package java.util;
9
10
73
74 public class TreeSet<E>
75 extends AbstractSet  <E>
76 implements SortedSet <E>, Cloneable , java.io.Serializable
77 {
78 private transient SortedMap <E,Object > m; private transient Set <E> keySet;
81 private static final Object PRESENT = new Object ();
83
84
87 private TreeSet(SortedMap <E,Object > m) {
88 this.m = m;
89 keySet = m.keySet();
90 }
91
92
105 public TreeSet() {
106 this(new TreeMap <E,Object >());
107 }
108
109
122 public TreeSet(Comparator <? super E> c) {
123 this(new TreeMap <E,Object >(c));
124 }
125
126
141 public TreeSet(Collection <? extends E> c) {
142 this();
143 addAll(c);
144 }
145
146
153 public TreeSet(SortedSet <E> s) {
154 this(s.comparator());
155 addAll(s);
156 }
157
158
164 public Iterator <E> iterator() {
165 return keySet.iterator();
166 }
167
168
173 public int size() {
174 return m.size();
175 }
176
177
182 public boolean isEmpty() {
183 return m.isEmpty();
184 }
185
186
195 public boolean contains(Object o) {
196 return m.containsKey(o);
197 }
198
199
209 public boolean add(E o) {
210 return m.put(o, PRESENT)==null;
211 }
212
213
222 public boolean remove(Object o) {
223 return m.remove(o)==PRESENT;
224 }
225
226
229 public void clear() {
230 m.clear();
231 }
232
233
243 public boolean addAll(Collection <? extends E> c) {
244 if (m.size()==0 && c.size() > 0 &&
246 c instanceof SortedSet &&
248 m instanceof TreeMap ) {
249 SortedSet <Map.Entry <E, Object >> set = (SortedSet <Map.Entry <E, Object >>) (SortedSet ) c;
250 TreeMap <E,Object > map = (TreeMap <E, Object >) m;
251 Comparator <? super E> cc = (Comparator <E>) set.comparator();
252 Comparator <? super E> mc = map.comparator();
253 if (cc==mc || (cc != null && cc.equals(mc))) {
254 map.addAllForTreeSet(set, PRESENT);
255 return true;
256 }
257 }
258 return super.addAll(c);
259 }
260
261
309 public SortedSet <E> subSet(E fromElement, E toElement) {
310 return new TreeSet <E>(m.subMap(fromElement, toElement));
311 }
312
313
346 public SortedSet <E> headSet(E toElement) {
347 return new TreeSet <E>(m.headMap(toElement));
348 }
349
350
385 public SortedSet <E> tailSet(E fromElement) {
386 return new TreeSet <E>(m.tailMap(fromElement));
387 }
388
389
396 public Comparator <? super E> comparator() {
397 return m.comparator();
398 }
399
400
406 public E first() {
407 return m.firstKey();
408 }
409
410
416 public E last() {
417 return m.lastKey();
418 }
419
420
426 public Object clone() {
427 TreeSet <E> clone = null;
428 try {
429 clone = (TreeSet <E>) super.clone();
430 } catch (CloneNotSupportedException e) {
431 throw new InternalError ();
432 }
433
434 clone.m = new TreeMap <E,Object >(m);
435 clone.keySet = clone.m.keySet();
436
437 return clone;
438 }
439
440
452 private void writeObject(java.io.ObjectOutputStream s)
453 throws java.io.IOException {
454 s.defaultWriteObject();
456
457 s.writeObject(m.comparator());
459
460 s.writeInt(m.size());
462
463 for (Iterator i=m.keySet().iterator(); i.hasNext(); )
465 s.writeObject(i.next());
466 }
467
468
472 private void readObject(java.io.ObjectInputStream s)
473 throws java.io.IOException , ClassNotFoundException {
474 s.defaultReadObject();
476
477 Comparator <E> c = (Comparator <E>) s.readObject();
479
480 TreeMap <E,Object > tm;
482 if (c==null)
483 tm = new TreeMap <E,Object >();
484 else
485 tm = new TreeMap <E,Object >(c);
486 m = tm;
487 keySet = m.keySet();
488
489 int size = s.readInt();
491
492 tm.readTreeSet(size, s, PRESENT);
493 }
494
495 private static final long serialVersionUID = -2479143000061671589L;
496 }
497 |
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