| 8 |
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package java.util; |
| 9 |
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|
| 10 |
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/** |
| 11 |
< |
* This class provides a skeletal implementation of the <tt>List</tt> |
| 11 |
> |
* This class provides a skeletal implementation of the {@code List} |
| 12 |
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* interface to minimize the effort required to implement this interface |
| 13 |
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* backed by a "random access" data store (such as an array). For sequential |
| 14 |
< |
* access data (such as a linked list), <tt>AbstractSequentialList</tt> should |
| 15 |
< |
* be used in preference to this class.<p> |
| 14 |
> |
* access data (such as a linked list), {@code AbstractSequentialList} should |
| 15 |
> |
* be used in preference to this class. |
| 16 |
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* |
| 17 |
< |
* To implement an unmodifiable list, the programmer needs only to extend this |
| 18 |
< |
* class and provide implementations for the <tt>get(int index)</tt> and |
| 19 |
< |
* <tt>size()</tt> methods.<p> |
| 17 |
> |
* <p>To implement an unmodifiable list, the programmer needs only to extend this |
| 18 |
> |
* class and provide implementations for the {@code get(int index)} and |
| 19 |
> |
* {@code size()} methods. |
| 20 |
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* |
| 21 |
< |
* To implement a modifiable list, the programmer must additionally override |
| 22 |
< |
* the <tt>set(int index, Object element)</tt> method (which otherwise throws |
| 23 |
< |
* an <tt>UnsupportedOperationException</tt>. If the list is variable-size |
| 24 |
< |
* the programmer must additionally override the <tt>add(int index, Object |
| 25 |
< |
* element)</tt> and <tt>remove(int index)</tt> methods.<p> |
| 21 |
> |
* <p>To implement a modifiable list, the programmer must additionally override |
| 22 |
> |
* the {@code set(int index, Object element)} method (which otherwise throws |
| 23 |
> |
* an {@code UnsupportedOperationException}. If the list is variable-size |
| 24 |
> |
* the programmer must additionally override the {@code add(int index, Object |
| 25 |
> |
* element)} and {@code remove(int index)} methods. |
| 26 |
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* |
| 27 |
< |
* The programmer should generally provide a void (no argument) and collection |
| 28 |
< |
* constructor, as per the recommendation in the <tt>Collection</tt> interface |
| 29 |
< |
* specification.<p> |
| 27 |
> |
* <p>The programmer should generally provide a void (no argument) and collection |
| 28 |
> |
* constructor, as per the recommendation in the {@code Collection} interface |
| 29 |
> |
* specification. |
| 30 |
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* |
| 31 |
< |
* Unlike the other abstract collection implementations, the programmer does |
| 31 |
> |
* <p>Unlike the other abstract collection implementations, the programmer does |
| 32 |
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* <i>not</i> have to provide an iterator implementation; the iterator and |
| 33 |
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* list iterator are implemented by this class, on top of the "random access" |
| 34 |
< |
* methods: <tt>get(int index)</tt>, <tt>set(int index, E element)</tt>, |
| 35 |
< |
* <tt>add(int index, E element)</tt> and <tt>remove(int index)</tt>.<p> |
| 34 |
> |
* methods: {@code get(int index)}, {@code set(int index, E element)}, |
| 35 |
> |
* {@code add(int index, E element)} and {@code remove(int index)}. |
| 36 |
|
* |
| 37 |
< |
* The documentation for each non-abstract methods in this class describes its |
| 37 |
> |
* <p>The documentation for each non-abstract methods in this class describes its |
| 38 |
|
* implementation in detail. Each of these methods may be overridden if the |
| 39 |
< |
* collection being implemented admits a more efficient implementation.<p> |
| 39 |
> |
* collection being implemented admits a more efficient implementation. |
| 40 |
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* |
| 41 |
< |
* This class is a member of the |
| 42 |
< |
* <a href="{@docRoot}/../guide/collections/index.html"> |
| 41 |
> |
* <p>This class is a member of the |
| 42 |
> |
* <a href="{@docRoot}/../technotes/guides/collections/index.html"> |
| 43 |
|
* Java Collections Framework</a>. |
| 44 |
|
* |
| 45 |
|
* @author Josh Bloch |
| 71 |
|
* classes should clearly specify in their documentation any restrictions |
| 72 |
|
* on what elements may be added. |
| 73 |
|
* |
| 74 |
< |
* <p>This implementation calls <tt>add(size(), e)</tt>. |
| 74 |
> |
* <p>This implementation calls {@code add(size(), e)}. |
| 75 |
|
* |
| 76 |
|
* <p>Note that this implementation throws an |
| 77 |
< |
* <tt>UnsupportedOperationException</tt> unless <tt>add(int, Object)</tt> |
| 77 |
> |
* {@code UnsupportedOperationException} unless {@code add(int, Object)} |
| 78 |
|
* is overridden. |
| 79 |
|
* |
| 80 |
|
* @param e element to be appended to this list |
| 81 |
< |
* @return <tt>true</tt> (as specified by {@link Collection#add}) |
| 82 |
< |
* @throws UnsupportedOperationException if the <tt>add</tt> operation |
| 81 |
> |
* @return {@code true} (as specified by {@link Collection#add}) |
| 82 |
> |
* @throws UnsupportedOperationException if the {@code add} operation |
| 83 |
|
* is not supported by this list |
| 84 |
|
* @throws ClassCastException if the class of the specified element |
| 85 |
|
* prevents it from being added to this list |
| 104 |
|
* {@inheritDoc} |
| 105 |
|
* |
| 106 |
|
* <p>This implementation always throws an |
| 107 |
< |
* <tt>UnsupportedOperationException</tt>. |
| 107 |
> |
* {@code UnsupportedOperationException}. |
| 108 |
|
* |
| 109 |
|
* @throws UnsupportedOperationException {@inheritDoc} |
| 110 |
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* @throws ClassCastException {@inheritDoc} |
| 120 |
|
* {@inheritDoc} |
| 121 |
|
* |
| 122 |
|
* <p>This implementation always throws an |
| 123 |
< |
* <tt>UnsupportedOperationException</tt>. |
| 123 |
> |
* {@code UnsupportedOperationException}. |
| 124 |
|
* |
| 125 |
|
* @throws UnsupportedOperationException {@inheritDoc} |
| 126 |
|
* @throws ClassCastException {@inheritDoc} |
| 136 |
|
* {@inheritDoc} |
| 137 |
|
* |
| 138 |
|
* <p>This implementation always throws an |
| 139 |
< |
* <tt>UnsupportedOperationException</tt>. |
| 139 |
> |
* {@code UnsupportedOperationException}. |
| 140 |
|
* |
| 141 |
|
* @throws UnsupportedOperationException {@inheritDoc} |
| 142 |
|
* @throws IndexOutOfBoundsException {@inheritDoc} |
| 152 |
|
* {@inheritDoc} |
| 153 |
|
* |
| 154 |
|
* <p>This implementation first gets a list iterator (with |
| 155 |
< |
* <tt>listIterator()</tt>). Then, it iterates over the list until the |
| 155 |
> |
* {@code listIterator()}). Then, it iterates over the list until the |
| 156 |
|
* specified element is found or the end of the list is reached. |
| 157 |
|
* |
| 158 |
|
* @throws ClassCastException {@inheritDoc} |
| 176 |
|
* {@inheritDoc} |
| 177 |
|
* |
| 178 |
|
* <p>This implementation first gets a list iterator that points to the end |
| 179 |
< |
* of the list (with <tt>listIterator(size())</tt>). Then, it iterates |
| 179 |
> |
* of the list (with {@code listIterator(size())}). Then, it iterates |
| 180 |
|
* backwards over the list until the specified element is found, or the |
| 181 |
|
* beginning of the list is reached. |
| 182 |
|
* |
| 204 |
|
* Removes all of the elements from this list (optional operation). |
| 205 |
|
* The list will be empty after this call returns. |
| 206 |
|
* |
| 207 |
< |
* <p>This implementation calls <tt>removeRange(0, size())</tt>. |
| 207 |
> |
* <p>This implementation calls {@code removeRange(0, size())}. |
| 208 |
|
* |
| 209 |
|
* <p>Note that this implementation throws an |
| 210 |
< |
* <tt>UnsupportedOperationException</tt> unless <tt>remove(int |
| 211 |
< |
* index)</tt> or <tt>removeRange(int fromIndex, int toIndex)</tt> is |
| 210 |
> |
* {@code UnsupportedOperationException} unless {@code remove(int |
| 211 |
> |
* index)} or {@code removeRange(int fromIndex, int toIndex)} is |
| 212 |
|
* overridden. |
| 213 |
|
* |
| 214 |
< |
* @throws UnsupportedOperationException if the <tt>clear</tt> operation |
| 214 |
> |
* @throws UnsupportedOperationException if the {@code clear} operation |
| 215 |
|
* is not supported by this list |
| 216 |
|
*/ |
| 217 |
|
public void clear() { |
| 224 |
|
* <p>This implementation gets an iterator over the specified collection and |
| 225 |
|
* iterates over it, inserting the elements obtained from the iterator |
| 226 |
|
* into this list at the appropriate position, one at a time, using |
| 227 |
< |
* <tt>add(int, Object)</tt>. Many implementations will override this |
| 227 |
> |
* {@code add(int, Object)}. Many implementations will override this |
| 228 |
|
* method for efficiency. |
| 229 |
|
* |
| 230 |
|
* <p>Note that this implementation throws an |
| 231 |
< |
* <tt>UnsupportedOperationException</tt> unless <tt>add(int, Object)</tt> |
| 231 |
> |
* {@code UnsupportedOperationException} unless {@code add(int, Object)} |
| 232 |
|
* is overridden. |
| 233 |
|
* |
| 234 |
|
* @throws UnsupportedOperationException {@inheritDoc} |
| 255 |
|
* sequence. <p> |
| 256 |
|
* |
| 257 |
|
* This implementation returns a straightforward implementation of the |
| 258 |
< |
* iterator interface, relying on the backing list's <tt>size()</tt>, |
| 259 |
< |
* <tt>get(int)</tt>, and <tt>remove(int)</tt> methods.<p> |
| 258 |
> |
* iterator interface, relying on the backing list's {@code size()}, |
| 259 |
> |
* {@code get(int)}, and {@code remove(int)} methods.<p> |
| 260 |
|
* |
| 261 |
|
* Note that the iterator returned by this method will throw an |
| 262 |
< |
* <tt>UnsupportedOperationException</tt> in response to its |
| 263 |
< |
* <tt>remove</tt> method unless the list's <tt>remove(int)</tt> method is |
| 262 |
> |
* {@code UnsupportedOperationException} in response to its |
| 263 |
> |
* {@code remove} method unless the list's {@code remove(int)} method is |
| 264 |
|
* overridden.<p> |
| 265 |
|
* |
| 266 |
|
* This implementation can be made to throw runtime exceptions in the face |
| 267 |
|
* of concurrent modification, as described in the specification for the |
| 268 |
< |
* (protected) <tt>modCount</tt> field. |
| 268 |
> |
* (protected) {@code modCount} field. |
| 269 |
|
* |
| 270 |
|
* @return an iterator over the elements in this list in proper sequence |
| 271 |
|
* |
| 278 |
|
/** |
| 279 |
|
* {@inheritDoc} |
| 280 |
|
* |
| 281 |
< |
* <p>This implementation returns <tt>listIterator(0)</tt>. |
| 281 |
> |
* <p>This implementation returns {@code listIterator(0)}. |
| 282 |
|
* |
| 283 |
|
* @see #listIterator(int) |
| 284 |
|
*/ |
| 290 |
|
* {@inheritDoc} |
| 291 |
|
* |
| 292 |
|
* <p>This implementation returns a straightforward implementation of the |
| 293 |
< |
* <tt>ListIterator</tt> interface that extends the implementation of the |
| 294 |
< |
* <tt>Iterator</tt> interface returned by the <tt>iterator()</tt> method. |
| 295 |
< |
* The <tt>ListIterator</tt> implementation relies on the backing list's |
| 296 |
< |
* <tt>get(int)</tt>, <tt>set(int, Object)</tt>, <tt>add(int, Object)</tt> |
| 297 |
< |
* and <tt>remove(int)</tt> methods. |
| 293 |
> |
* {@code ListIterator} interface that extends the implementation of the |
| 294 |
> |
* {@code Iterator} interface returned by the {@code iterator()} method. |
| 295 |
> |
* The {@code ListIterator} implementation relies on the backing list's |
| 296 |
> |
* {@code get(int)}, {@code set(int, Object)}, {@code add(int, Object)} |
| 297 |
> |
* and {@code remove(int)} methods. |
| 298 |
|
* |
| 299 |
|
* <p>Note that the list iterator returned by this implementation will |
| 300 |
< |
* throw an <tt>UnsupportedOperationException</tt> in response to its |
| 301 |
< |
* <tt>remove</tt>, <tt>set</tt> and <tt>add</tt> methods unless the |
| 302 |
< |
* list's <tt>remove(int)</tt>, <tt>set(int, Object)</tt>, and |
| 303 |
< |
* <tt>add(int, Object)</tt> methods are overridden. |
| 300 |
> |
* throw an {@code UnsupportedOperationException} in response to its |
| 301 |
> |
* {@code remove}, {@code set} and {@code add} methods unless the |
| 302 |
> |
* list's {@code remove(int)}, {@code set(int, Object)}, and |
| 303 |
> |
* {@code add(int, Object)} methods are overridden. |
| 304 |
|
* |
| 305 |
|
* <p>This implementation can be made to throw runtime exceptions in the |
| 306 |
|
* face of concurrent modification, as described in the specification for |
| 307 |
< |
* the (protected) <tt>modCount</tt> field. |
| 307 |
> |
* the (protected) {@code modCount} field. |
| 308 |
|
* |
| 309 |
|
* @throws IndexOutOfBoundsException {@inheritDoc} |
| 310 |
|
* |
| 342 |
|
} |
| 343 |
|
|
| 344 |
|
public E next() { |
| 345 |
< |
try { |
| 346 |
< |
int i = cursor; |
| 347 |
< |
E next = get(i); |
| 348 |
< |
lastRet = i; |
| 349 |
< |
cursor = i + 1; |
| 350 |
< |
return next; |
| 351 |
< |
} catch (IndexOutOfBoundsException ex) { |
| 352 |
< |
throw new NoSuchElementException(); |
| 353 |
< |
} finally { |
| 354 |
< |
if (expectedModCount != modCount) |
| 355 |
< |
throw new ConcurrentModificationException(); |
| 356 |
< |
} |
| 345 |
> |
checkForComodification(); |
| 346 |
> |
try { |
| 347 |
> |
E next = get(cursor); |
| 348 |
> |
lastRet = cursor++; |
| 349 |
> |
return next; |
| 350 |
> |
} catch (IndexOutOfBoundsException e) { |
| 351 |
> |
checkForComodification(); |
| 352 |
> |
throw new NoSuchElementException(); |
| 353 |
> |
} |
| 354 |
|
} |
| 355 |
|
|
| 356 |
|
public void remove() { |
| 357 |
|
if (lastRet == -1) |
| 358 |
|
throw new IllegalStateException(); |
| 359 |
< |
if (expectedModCount != modCount) |
| 360 |
< |
throw new ConcurrentModificationException(); |
| 359 |
> |
checkForComodification(); |
| 360 |
> |
|
| 361 |
|
try { |
| 362 |
|
AbstractList.this.remove(lastRet); |
| 363 |
|
if (lastRet < cursor) |
| 368 |
|
throw new ConcurrentModificationException(); |
| 369 |
|
} |
| 370 |
|
} |
| 371 |
+ |
|
| 372 |
+ |
final void checkForComodification() { |
| 373 |
+ |
if (modCount != expectedModCount) |
| 374 |
+ |
throw new ConcurrentModificationException(); |
| 375 |
+ |
} |
| 376 |
|
} |
| 377 |
|
|
| 378 |
|
private class ListItr extends Itr implements ListIterator<E> { |
| 384 |
|
return cursor != 0; |
| 385 |
|
} |
| 386 |
|
|
| 385 |
– |
public int nextIndex() { |
| 386 |
– |
return cursor; |
| 387 |
– |
} |
| 388 |
– |
|
| 389 |
– |
public int previousIndex() { |
| 390 |
– |
return cursor - 1; |
| 391 |
– |
} |
| 392 |
– |
|
| 387 |
|
public E previous() { |
| 388 |
+ |
checkForComodification(); |
| 389 |
|
try { |
| 390 |
|
int i = cursor - 1; |
| 391 |
< |
E prev = get(i); |
| 392 |
< |
lastRet = i; |
| 393 |
< |
cursor = i; |
| 394 |
< |
return prev; |
| 395 |
< |
} catch (IndexOutOfBoundsException ex) { |
| 391 |
> |
E previous = get(i); |
| 392 |
> |
lastRet = cursor = i; |
| 393 |
> |
return previous; |
| 394 |
> |
} catch (IndexOutOfBoundsException e) { |
| 395 |
> |
checkForComodification(); |
| 396 |
|
throw new NoSuchElementException(); |
| 402 |
– |
} finally { |
| 403 |
– |
if (expectedModCount != modCount) |
| 404 |
– |
throw new ConcurrentModificationException(); |
| 397 |
|
} |
| 398 |
|
} |
| 399 |
|
|
| 400 |
+ |
public int nextIndex() { |
| 401 |
+ |
return cursor; |
| 402 |
+ |
} |
| 403 |
+ |
|
| 404 |
+ |
public int previousIndex() { |
| 405 |
+ |
return cursor-1; |
| 406 |
+ |
} |
| 407 |
+ |
|
| 408 |
|
public void set(E e) { |
| 409 |
|
if (lastRet == -1) |
| 410 |
|
throw new IllegalStateException(); |
| 411 |
< |
if (expectedModCount != modCount) |
| 412 |
< |
throw new ConcurrentModificationException(); |
| 411 |
> |
checkForComodification(); |
| 412 |
> |
|
| 413 |
|
try { |
| 414 |
|
AbstractList.this.set(lastRet, e); |
| 415 |
|
expectedModCount = modCount; |
| 419 |
|
} |
| 420 |
|
|
| 421 |
|
public void add(E e) { |
| 422 |
< |
if (expectedModCount != modCount) |
| 423 |
< |
throw new ConcurrentModificationException(); |
| 422 |
> |
checkForComodification(); |
| 423 |
> |
|
| 424 |
|
try { |
| 425 |
|
int i = cursor; |
| 426 |
|
AbstractList.this.add(i, e); |
| 437 |
|
* {@inheritDoc} |
| 438 |
|
* |
| 439 |
|
* <p>This implementation returns a list that subclasses |
| 440 |
< |
* <tt>AbstractList</tt>. The subclass stores, in private fields, the |
| 440 |
> |
* {@code AbstractList}. The subclass stores, in private fields, the |
| 441 |
|
* offset of the subList within the backing list, the size of the subList |
| 442 |
|
* (which can change over its lifetime), and the expected |
| 443 |
< |
* <tt>modCount</tt> value of the backing list. There are two variants |
| 444 |
< |
* of the subclass, one of which implements <tt>RandomAccess</tt>. |
| 445 |
< |
* If this list implements <tt>RandomAccess</tt> the returned list will |
| 446 |
< |
* be an instance of the subclass that implements <tt>RandomAccess</tt>. |
| 447 |
< |
* |
| 448 |
< |
* <p>The subclass's <tt>set(int, Object)</tt>, <tt>get(int)</tt>, |
| 449 |
< |
* <tt>add(int, Object)</tt>, <tt>remove(int)</tt>, <tt>addAll(int, |
| 450 |
< |
* Collection)</tt> and <tt>removeRange(int, int)</tt> methods all |
| 443 |
> |
* {@code modCount} value of the backing list. There are two variants |
| 444 |
> |
* of the subclass, one of which implements {@code RandomAccess}. |
| 445 |
> |
* If this list implements {@code RandomAccess} the returned list will |
| 446 |
> |
* be an instance of the subclass that implements {@code RandomAccess}. |
| 447 |
> |
* |
| 448 |
> |
* <p>The subclass's {@code set(int, Object)}, {@code get(int)}, |
| 449 |
> |
* {@code add(int, Object)}, {@code remove(int)}, {@code addAll(int, |
| 450 |
> |
* Collection)} and {@code removeRange(int, int)} methods all |
| 451 |
|
* delegate to the corresponding methods on the backing abstract list, |
| 452 |
|
* after bounds-checking the index and adjusting for the offset. The |
| 453 |
< |
* <tt>addAll(Collection c)</tt> method merely returns <tt>addAll(size, |
| 454 |
< |
* c)</tt>. |
| 453 |
> |
* {@code addAll(Collection c)} method merely returns {@code addAll(size, |
| 454 |
> |
* c)}. |
| 455 |
|
* |
| 456 |
< |
* <p>The <tt>listIterator(int)</tt> method returns a "wrapper object" |
| 456 |
> |
* <p>The {@code listIterator(int)} method returns a "wrapper object" |
| 457 |
|
* over a list iterator on the backing list, which is created with the |
| 458 |
< |
* corresponding method on the backing list. The <tt>iterator</tt> method |
| 459 |
< |
* merely returns <tt>listIterator()</tt>, and the <tt>size</tt> method |
| 460 |
< |
* merely returns the subclass's <tt>size</tt> field. |
| 458 |
> |
* corresponding method on the backing list. The {@code iterator} method |
| 459 |
> |
* merely returns {@code listIterator()}, and the {@code size} method |
| 460 |
> |
* merely returns the subclass's {@code size} field. |
| 461 |
|
* |
| 462 |
< |
* <p>All methods first check to see if the actual <tt>modCount</tt> of |
| 462 |
> |
* <p>All methods first check to see if the actual {@code modCount} of |
| 463 |
|
* the backing list is equal to its expected value, and throw a |
| 464 |
< |
* <tt>ConcurrentModificationException</tt> if it is not. |
| 464 |
> |
* {@code ConcurrentModificationException} if it is not. |
| 465 |
|
* |
| 466 |
|
* @throws IndexOutOfBoundsException endpoint index value out of range |
| 467 |
< |
* <tt>(fromIndex < 0 || toIndex > size)</tt> |
| 467 |
> |
* {@code (fromIndex < 0 || toIndex > size)} |
| 468 |
|
* @throws IllegalArgumentException if the endpoint indices are out of order |
| 469 |
< |
* <tt>(fromIndex > toIndex)</tt> |
| 469 |
> |
* {@code (fromIndex > toIndex)} |
| 470 |
|
*/ |
| 471 |
|
public List<E> subList(int fromIndex, int toIndex) { |
| 472 |
|
return (this instanceof RandomAccess ? |
| 473 |
< |
new RandomAccessSubList<E>(this, fromIndex, toIndex) : |
| 474 |
< |
new SubList<E>(this, fromIndex, toIndex)); |
| 473 |
> |
new RandomAccessSubList(this, this, fromIndex, fromIndex, toIndex) : |
| 474 |
> |
new SubList(this, this, fromIndex, fromIndex, toIndex)); |
| 475 |
|
} |
| 476 |
|
|
| 477 |
|
// Comparison and hashing |
| 478 |
|
|
| 479 |
|
/** |
| 480 |
|
* Compares the specified object with this list for equality. Returns |
| 481 |
< |
* <tt>true</tt> if and only if the specified object is also a list, both |
| 481 |
> |
* {@code true} if and only if the specified object is also a list, both |
| 482 |
|
* lists have the same size, and all corresponding pairs of elements in |
| 483 |
< |
* the two lists are <i>equal</i>. (Two elements <tt>e1</tt> and |
| 484 |
< |
* <tt>e2</tt> are <i>equal</i> if <tt>(e1==null ? e2==null : |
| 485 |
< |
* e1.equals(e2))</tt>.) In other words, two lists are defined to be |
| 483 |
> |
* the two lists are <i>equal</i>. (Two elements {@code e1} and |
| 484 |
> |
* {@code e2} are <i>equal</i> if {@code (e1==null ? e2==null : |
| 485 |
> |
* e1.equals(e2))}.) In other words, two lists are defined to be |
| 486 |
|
* equal if they contain the same elements in the same order.<p> |
| 487 |
|
* |
| 488 |
|
* This implementation first checks if the specified object is this |
| 489 |
< |
* list. If so, it returns <tt>true</tt>; if not, it checks if the |
| 490 |
< |
* specified object is a list. If not, it returns <tt>false</tt>; if so, |
| 489 |
> |
* list. If so, it returns {@code true}; if not, it checks if the |
| 490 |
> |
* specified object is a list. If not, it returns {@code false}; if so, |
| 491 |
|
* it iterates over both lists, comparing corresponding pairs of elements. |
| 492 |
< |
* If any comparison returns <tt>false</tt>, this method returns |
| 493 |
< |
* <tt>false</tt>. If either iterator runs out of elements before the |
| 494 |
< |
* other it returns <tt>false</tt> (as the lists are of unequal length); |
| 495 |
< |
* otherwise it returns <tt>true</tt> when the iterations complete. |
| 492 |
> |
* If any comparison returns {@code false}, this method returns |
| 493 |
> |
* {@code false}. If either iterator runs out of elements before the |
| 494 |
> |
* other it returns {@code false} (as the lists are of unequal length); |
| 495 |
> |
* otherwise it returns {@code true} when the iterations complete. |
| 496 |
|
* |
| 497 |
|
* @param o the object to be compared for equality with this list |
| 498 |
< |
* @return <tt>true</tt> if the specified object is equal to this list |
| 498 |
> |
* @return {@code true} if the specified object is equal to this list |
| 499 |
|
*/ |
| 500 |
|
public boolean equals(Object o) { |
| 501 |
|
if (o == this) |
| 535 |
|
|
| 536 |
|
/** |
| 537 |
|
* Removes from this list all of the elements whose index is between |
| 538 |
< |
* <tt>fromIndex</tt>, inclusive, and <tt>toIndex</tt>, exclusive. |
| 538 |
> |
* {@code fromIndex}, inclusive, and {@code toIndex}, exclusive. |
| 539 |
|
* Shifts any succeeding elements to the left (reduces their index). |
| 540 |
< |
* This call shortens the ArrayList by <tt>(toIndex - fromIndex)</tt> |
| 541 |
< |
* elements. (If <tt>toIndex==fromIndex</tt>, this operation has no |
| 540 |
> |
* This call shortens the ArrayList by {@code (toIndex - fromIndex)} |
| 541 |
> |
* elements. (If {@code toIndex==fromIndex}, this operation has no |
| 542 |
|
* effect.)<p> |
| 543 |
|
* |
| 544 |
< |
* This method is called by the <tt>clear</tt> operation on this list |
| 544 |
> |
* This method is called by the {@code clear} operation on this list |
| 545 |
|
* and its subLists. Overriding this method to take advantage of |
| 546 |
|
* the internals of the list implementation can <i>substantially</i> |
| 547 |
< |
* improve the performance of the <tt>clear</tt> operation on this list |
| 547 |
> |
* improve the performance of the {@code clear} operation on this list |
| 548 |
|
* and its subLists.<p> |
| 549 |
|
* |
| 550 |
|
* This implementation gets a list iterator positioned before |
| 551 |
< |
* <tt>fromIndex</tt>, and repeatedly calls <tt>ListIterator.next</tt> |
| 552 |
< |
* followed by <tt>ListIterator.remove</tt> until the entire range has |
| 553 |
< |
* been removed. <b>Note: if <tt>ListIterator.remove</tt> requires linear |
| 551 |
> |
* {@code fromIndex}, and repeatedly calls {@code ListIterator.next} |
| 552 |
> |
* followed by {@code ListIterator.remove} until the entire range has |
| 553 |
> |
* been removed. <b>Note: if {@code ListIterator.remove} requires linear |
| 554 |
|
* time, this implementation requires quadratic time.</b> |
| 555 |
|
* |
| 556 |
|
* @param fromIndex index of first element to be removed |
| 571 |
|
* progress may yield incorrect results.<p> |
| 572 |
|
* |
| 573 |
|
* This field is used by the iterator and list iterator implementation |
| 574 |
< |
* returned by the <tt>iterator</tt> and <tt>listIterator</tt> methods. |
| 574 |
> |
* returned by the {@code iterator} and {@code listIterator} methods. |
| 575 |
|
* If the value of this field changes unexpectedly, the iterator (or list |
| 576 |
< |
* iterator) will throw a <tt>ConcurrentModificationException</tt> in |
| 577 |
< |
* response to the <tt>next</tt>, <tt>remove</tt>, <tt>previous</tt>, |
| 578 |
< |
* <tt>set</tt> or <tt>add</tt> operations. This provides |
| 576 |
> |
* iterator) will throw a {@code ConcurrentModificationException} in |
| 577 |
> |
* response to the {@code next}, {@code remove}, {@code previous}, |
| 578 |
> |
* {@code set} or {@code add} operations. This provides |
| 579 |
|
* <i>fail-fast</i> behavior, rather than non-deterministic behavior in |
| 580 |
|
* the face of concurrent modification during iteration.<p> |
| 581 |
|
* |
| 582 |
|
* <b>Use of this field by subclasses is optional.</b> If a subclass |
| 583 |
|
* wishes to provide fail-fast iterators (and list iterators), then it |
| 584 |
< |
* merely has to increment this field in its <tt>add(int, Object)</tt> and |
| 585 |
< |
* <tt>remove(int)</tt> methods (and any other methods that it overrides |
| 584 |
> |
* merely has to increment this field in its {@code add(int, Object)} and |
| 585 |
> |
* {@code remove(int)} methods (and any other methods that it overrides |
| 586 |
|
* that result in structural modifications to the list). A single call to |
| 587 |
< |
* <tt>add(int, Object)</tt> or <tt>remove(int)</tt> must add no more than |
| 587 |
> |
* {@code add(int, Object)} or {@code remove(int)} must add no more than |
| 588 |
|
* one to this field, or the iterators (and list iterators) will throw |
| 589 |
< |
* bogus <tt>ConcurrentModificationExceptions</tt>. If an implementation |
| 589 |
> |
* bogus {@code ConcurrentModificationExceptions}. If an implementation |
| 590 |
|
* does not wish to provide fail-fast iterators, this field may be |
| 591 |
|
* ignored. |
| 592 |
|
*/ |
| 593 |
|
protected transient int modCount = 0; |
| 594 |
|
} |
| 595 |
|
|
| 596 |
+ |
/** |
| 597 |
+ |
* Generic sublists. Non-nested to enable construction by other |
| 598 |
+ |
* classes in this package. |
| 599 |
+ |
*/ |
| 600 |
|
class SubList<E> extends AbstractList<E> { |
| 601 |
< |
private AbstractList<E> l; |
| 602 |
< |
private int offset; |
| 603 |
< |
private int size; |
| 604 |
< |
private int expectedModCount; |
| 605 |
< |
|
| 606 |
< |
SubList(AbstractList<E> list, int fromIndex, int toIndex) { |
| 601 |
> |
/* |
| 602 |
> |
* A SubList has both a "base", the ultimate backing list, as well |
| 603 |
> |
* as a "parent", which is the list or sublist creating this |
| 604 |
> |
* sublist. All methods that may cause structural modifications |
| 605 |
> |
* must propagate through the parent link, with O(k) performance |
| 606 |
> |
* where k is sublist depth. For example in the case of a |
| 607 |
> |
* sub-sub-list, invoking remove(x) will result in a chain of |
| 608 |
> |
* three remove calls. However, all other non-structurally |
| 609 |
> |
* modifying methods can bypass this chain, and relay directly to |
| 610 |
> |
* the base list. In particular, doing so signficantly speeds up |
| 611 |
> |
* the performance of iterators for deeply-nested sublists. |
| 612 |
> |
*/ |
| 613 |
> |
final AbstractList<E> base; // Backing list |
| 614 |
> |
final AbstractList<E> parent; // Parent list |
| 615 |
> |
final int baseOffset; // index wrt base |
| 616 |
> |
final int parentOffset; // index wrt parent |
| 617 |
> |
int length; // Number of elements in this sublist |
| 618 |
> |
|
| 619 |
> |
SubList(AbstractList<E> base, |
| 620 |
> |
AbstractList<E> parent, |
| 621 |
> |
int baseIndex, |
| 622 |
> |
int fromIndex, |
| 623 |
> |
int toIndex) { |
| 624 |
|
if (fromIndex < 0) |
| 625 |
|
throw new IndexOutOfBoundsException("fromIndex = " + fromIndex); |
| 626 |
< |
if (toIndex > list.size()) |
| 626 |
> |
if (toIndex > parent.size()) |
| 627 |
|
throw new IndexOutOfBoundsException("toIndex = " + toIndex); |
| 628 |
|
if (fromIndex > toIndex) |
| 629 |
|
throw new IllegalArgumentException("fromIndex(" + fromIndex + |
| 630 |
|
") > toIndex(" + toIndex + ")"); |
| 631 |
< |
l = list; |
| 632 |
< |
offset = fromIndex; |
| 633 |
< |
size = toIndex - fromIndex; |
| 634 |
< |
expectedModCount = l.modCount; |
| 631 |
> |
this.base = base; |
| 632 |
> |
this.parent = parent; |
| 633 |
> |
this.baseOffset = baseIndex; |
| 634 |
> |
this.parentOffset = fromIndex; |
| 635 |
> |
this.length = toIndex - fromIndex; |
| 636 |
> |
this.modCount = base.modCount; |
| 637 |
> |
} |
| 638 |
> |
|
| 639 |
> |
/** |
| 640 |
> |
* Returns an IndexOutOfBoundsException with nicer message |
| 641 |
> |
*/ |
| 642 |
> |
private IndexOutOfBoundsException indexError(int index) { |
| 643 |
> |
return new IndexOutOfBoundsException("Index: " + index + |
| 644 |
> |
", Size: " + length); |
| 645 |
|
} |
| 646 |
|
|
| 647 |
|
public E set(int index, E element) { |
| 648 |
< |
rangeCheck(index); |
| 649 |
< |
checkForComodification(); |
| 650 |
< |
return l.set(index+offset, element); |
| 648 |
> |
if (index < 0 || index >= length) |
| 649 |
> |
throw indexError(index); |
| 650 |
> |
if (base.modCount != modCount) |
| 651 |
> |
throw new ConcurrentModificationException(); |
| 652 |
> |
return base.set(index + baseOffset, element); |
| 653 |
|
} |
| 654 |
|
|
| 655 |
|
public E get(int index) { |
| 656 |
< |
rangeCheck(index); |
| 657 |
< |
checkForComodification(); |
| 658 |
< |
return l.get(index+offset); |
| 656 |
> |
if (index < 0 || index >= length) |
| 657 |
> |
throw indexError(index); |
| 658 |
> |
if (base.modCount != modCount) |
| 659 |
> |
throw new ConcurrentModificationException(); |
| 660 |
> |
return base.get(index + baseOffset); |
| 661 |
|
} |
| 662 |
|
|
| 663 |
|
public int size() { |
| 664 |
< |
checkForComodification(); |
| 665 |
< |
return size; |
| 664 |
> |
if (base.modCount != modCount) |
| 665 |
> |
throw new ConcurrentModificationException(); |
| 666 |
> |
return length; |
| 667 |
|
} |
| 668 |
|
|
| 669 |
|
public void add(int index, E element) { |
| 670 |
< |
if (index<0 || index>size) |
| 671 |
< |
throw new IndexOutOfBoundsException(); |
| 672 |
< |
checkForComodification(); |
| 673 |
< |
l.add(index+offset, element); |
| 674 |
< |
expectedModCount = l.modCount; |
| 675 |
< |
size++; |
| 676 |
< |
modCount++; |
| 670 |
> |
if (index < 0 || index>length) |
| 671 |
> |
throw indexError(index); |
| 672 |
> |
if (base.modCount != modCount) |
| 673 |
> |
throw new ConcurrentModificationException(); |
| 674 |
> |
parent.add(index + parentOffset, element); |
| 675 |
> |
length++; |
| 676 |
> |
modCount = base.modCount; |
| 677 |
|
} |
| 678 |
|
|
| 679 |
|
public E remove(int index) { |
| 680 |
< |
rangeCheck(index); |
| 681 |
< |
checkForComodification(); |
| 682 |
< |
E result = l.remove(index+offset); |
| 683 |
< |
expectedModCount = l.modCount; |
| 684 |
< |
size--; |
| 685 |
< |
modCount++; |
| 680 |
> |
if (index < 0 || index >= length) |
| 681 |
> |
throw indexError(index); |
| 682 |
> |
if (base.modCount != modCount) |
| 683 |
> |
throw new ConcurrentModificationException(); |
| 684 |
> |
E result = parent.remove(index + parentOffset); |
| 685 |
> |
length--; |
| 686 |
> |
modCount = base.modCount; |
| 687 |
|
return result; |
| 688 |
|
} |
| 689 |
|
|
| 690 |
|
protected void removeRange(int fromIndex, int toIndex) { |
| 691 |
< |
checkForComodification(); |
| 692 |
< |
l.removeRange(fromIndex+offset, toIndex+offset); |
| 693 |
< |
expectedModCount = l.modCount; |
| 694 |
< |
size -= (toIndex-fromIndex); |
| 695 |
< |
modCount++; |
| 691 |
> |
if (base.modCount != modCount) |
| 692 |
> |
throw new ConcurrentModificationException(); |
| 693 |
> |
parent.removeRange(fromIndex + parentOffset, toIndex + parentOffset); |
| 694 |
> |
length -= (toIndex-fromIndex); |
| 695 |
> |
modCount = base.modCount; |
| 696 |
|
} |
| 697 |
|
|
| 698 |
|
public boolean addAll(Collection<? extends E> c) { |
| 699 |
< |
return addAll(size, c); |
| 699 |
> |
return addAll(length, c); |
| 700 |
|
} |
| 701 |
|
|
| 702 |
|
public boolean addAll(int index, Collection<? extends E> c) { |
| 703 |
< |
if (index<0 || index>size) |
| 704 |
< |
throw new IndexOutOfBoundsException( |
| 668 |
< |
"Index: "+index+", Size: "+size); |
| 703 |
> |
if (index < 0 || index > length) |
| 704 |
> |
throw indexError(index); |
| 705 |
|
int cSize = c.size(); |
| 706 |
|
if (cSize==0) |
| 707 |
|
return false; |
| 708 |
|
|
| 709 |
< |
checkForComodification(); |
| 710 |
< |
l.addAll(offset+index, c); |
| 711 |
< |
expectedModCount = l.modCount; |
| 712 |
< |
size += cSize; |
| 713 |
< |
modCount++; |
| 709 |
> |
if (base.modCount != modCount) |
| 710 |
> |
throw new ConcurrentModificationException(); |
| 711 |
> |
parent.addAll(parentOffset + index, c); |
| 712 |
> |
length += cSize; |
| 713 |
> |
modCount = base.modCount; |
| 714 |
|
return true; |
| 715 |
|
} |
| 716 |
|
|
| 717 |
+ |
public List<E> subList(int fromIndex, int toIndex) { |
| 718 |
+ |
return new SubList(base, this, fromIndex + baseOffset, |
| 719 |
+ |
fromIndex, toIndex); |
| 720 |
+ |
} |
| 721 |
+ |
|
| 722 |
|
public Iterator<E> iterator() { |
| 723 |
< |
return listIterator(); |
| 723 |
> |
return new SubListIterator(this, 0); |
| 724 |
|
} |
| 725 |
|
|
| 726 |
< |
public ListIterator<E> listIterator(final int index) { |
| 727 |
< |
checkForComodification(); |
| 728 |
< |
if (index<0 || index>size) |
| 688 |
< |
throw new IndexOutOfBoundsException( |
| 689 |
< |
"Index: "+index+", Size: "+size); |
| 726 |
> |
public ListIterator<E> listIterator() { |
| 727 |
> |
return new SubListIterator(this, 0); |
| 728 |
> |
} |
| 729 |
|
|
| 730 |
< |
return new ListIterator<E>() { |
| 731 |
< |
private ListIterator<E> i = l.listIterator(index+offset); |
| 730 |
> |
public ListIterator<E> listIterator(int index) { |
| 731 |
> |
if (index < 0 || index>length) |
| 732 |
> |
throw indexError(index); |
| 733 |
> |
return new SubListIterator(this, index); |
| 734 |
> |
} |
| 735 |
|
|
| 736 |
< |
public boolean hasNext() { |
| 737 |
< |
return nextIndex() < size; |
| 738 |
< |
} |
| 736 |
> |
/** |
| 737 |
> |
* Generic sublist iterator obeying fastfail semantics via |
| 738 |
> |
* modCount. The hasNext and next methods locally check for |
| 739 |
> |
* in-range indices before relaying to backing list to get |
| 740 |
> |
* element. If this either encounters an unexpected modCount or |
| 741 |
> |
* fails, the backing list must have been concurrently modified, |
| 742 |
> |
* and is so reported. The add and remove methods performing |
| 743 |
> |
* structural modifications instead relay them through the |
| 744 |
> |
* sublist. |
| 745 |
> |
*/ |
| 746 |
> |
private static final class SubListIterator<E> implements ListIterator<E> { |
| 747 |
> |
final SubList<E> outer; // Sublist creating this iteraor |
| 748 |
> |
final AbstractList<E> base; // base list |
| 749 |
> |
final int offset; // Cursor offset wrt base |
| 750 |
> |
int cursor; // Current index |
| 751 |
> |
int fence; // Upper bound on cursor |
| 752 |
> |
int lastRet; // Index of returned element, or -1 |
| 753 |
> |
int expectedModCount; // Expected modCount of base |
| 754 |
> |
|
| 755 |
> |
SubListIterator(SubList<E> list, int index) { |
| 756 |
> |
this.lastRet = -1; |
| 757 |
> |
this.cursor = index; |
| 758 |
> |
this.outer = list; |
| 759 |
> |
this.offset = list.baseOffset; |
| 760 |
> |
this.fence = list.length; |
| 761 |
> |
this.base = list.base; |
| 762 |
> |
this.expectedModCount = base.modCount; |
| 763 |
> |
} |
| 764 |
|
|
| 765 |
< |
public E next() { |
| 766 |
< |
if (hasNext()) |
| 767 |
< |
return i.next(); |
| 701 |
< |
else |
| 702 |
< |
throw new NoSuchElementException(); |
| 703 |
< |
} |
| 765 |
> |
public boolean hasNext() { |
| 766 |
> |
return cursor < fence; |
| 767 |
> |
} |
| 768 |
|
|
| 769 |
< |
public boolean hasPrevious() { |
| 770 |
< |
return previousIndex() >= 0; |
| 771 |
< |
} |
| 769 |
> |
public boolean hasPrevious() { |
| 770 |
> |
return cursor > 0; |
| 771 |
> |
} |
| 772 |
|
|
| 773 |
< |
public E previous() { |
| 774 |
< |
if (hasPrevious()) |
| 775 |
< |
return i.previous(); |
| 712 |
< |
else |
| 713 |
< |
throw new NoSuchElementException(); |
| 714 |
< |
} |
| 773 |
> |
public int nextIndex() { |
| 774 |
> |
return cursor; |
| 775 |
> |
} |
| 776 |
|
|
| 777 |
< |
public int nextIndex() { |
| 778 |
< |
return i.nextIndex() - offset; |
| 779 |
< |
} |
| 777 |
> |
public int previousIndex() { |
| 778 |
> |
return cursor - 1; |
| 779 |
> |
} |
| 780 |
|
|
| 781 |
< |
public int previousIndex() { |
| 782 |
< |
return i.previousIndex() - offset; |
| 781 |
> |
public E next() { |
| 782 |
> |
int i = cursor; |
| 783 |
> |
if (cursor >= fence) |
| 784 |
> |
throw new NoSuchElementException(); |
| 785 |
> |
if (expectedModCount == base.modCount) { |
| 786 |
> |
try { |
| 787 |
> |
Object next = base.get(i + offset); |
| 788 |
> |
lastRet = i; |
| 789 |
> |
cursor = i + 1; |
| 790 |
> |
return (E)next; |
| 791 |
> |
} catch (IndexOutOfBoundsException fallThrough) { |
| 792 |
> |
} |
| 793 |
|
} |
| 794 |
+ |
throw new ConcurrentModificationException(); |
| 795 |
+ |
} |
| 796 |
|
|
| 797 |
< |
public void remove() { |
| 798 |
< |
i.remove(); |
| 799 |
< |
expectedModCount = l.modCount; |
| 800 |
< |
size--; |
| 801 |
< |
modCount++; |
| 797 |
> |
public E previous() { |
| 798 |
> |
int i = cursor - 1; |
| 799 |
> |
if (i < 0) |
| 800 |
> |
throw new NoSuchElementException(); |
| 801 |
> |
if (expectedModCount == base.modCount) { |
| 802 |
> |
try { |
| 803 |
> |
Object prev = base.get(i + offset); |
| 804 |
> |
lastRet = i; |
| 805 |
> |
cursor = i; |
| 806 |
> |
return (E)prev; |
| 807 |
> |
} catch (IndexOutOfBoundsException fallThrough) { |
| 808 |
> |
} |
| 809 |
|
} |
| 810 |
+ |
throw new ConcurrentModificationException(); |
| 811 |
+ |
} |
| 812 |
|
|
| 813 |
< |
public void set(E e) { |
| 814 |
< |
i.set(e); |
| 813 |
> |
public void set(E e) { |
| 814 |
> |
if (lastRet < 0) |
| 815 |
> |
throw new IllegalStateException(); |
| 816 |
> |
if (expectedModCount != base.modCount) |
| 817 |
> |
throw new ConcurrentModificationException(); |
| 818 |
> |
try { |
| 819 |
> |
outer.set(lastRet, e); |
| 820 |
> |
expectedModCount = base.modCount; |
| 821 |
> |
} catch (IndexOutOfBoundsException ex) { |
| 822 |
> |
throw new ConcurrentModificationException(); |
| 823 |
|
} |
| 824 |
+ |
} |
| 825 |
|
|
| 826 |
< |
public void add(E e) { |
| 827 |
< |
i.add(e); |
| 828 |
< |
expectedModCount = l.modCount; |
| 829 |
< |
size++; |
| 830 |
< |
modCount++; |
| 826 |
> |
public void remove() { |
| 827 |
> |
int i = lastRet; |
| 828 |
> |
if (i < 0) |
| 829 |
> |
throw new IllegalStateException(); |
| 830 |
> |
if (expectedModCount != base.modCount) |
| 831 |
> |
throw new ConcurrentModificationException(); |
| 832 |
> |
try { |
| 833 |
> |
outer.remove(i); |
| 834 |
> |
if (i < cursor) |
| 835 |
> |
cursor--; |
| 836 |
> |
lastRet = -1; |
| 837 |
> |
fence = outer.length; |
| 838 |
> |
expectedModCount = base.modCount; |
| 839 |
> |
} catch (IndexOutOfBoundsException ex) { |
| 840 |
> |
throw new ConcurrentModificationException(); |
| 841 |
|
} |
| 842 |
< |
}; |
| 742 |
< |
} |
| 743 |
< |
|
| 744 |
< |
public List<E> subList(int fromIndex, int toIndex) { |
| 745 |
< |
return new SubList<E>(this, fromIndex, toIndex); |
| 746 |
< |
} |
| 842 |
> |
} |
| 843 |
|
|
| 844 |
< |
private void rangeCheck(int index) { |
| 845 |
< |
if (index<0 || index>=size) |
| 846 |
< |
throw new IndexOutOfBoundsException("Index: "+index+ |
| 847 |
< |
",Size: "+size); |
| 844 |
> |
public void add(E e) { |
| 845 |
> |
if (expectedModCount != base.modCount) |
| 846 |
> |
throw new ConcurrentModificationException(); |
| 847 |
> |
try { |
| 848 |
> |
int i = cursor; |
| 849 |
> |
outer.add(i, e); |
| 850 |
> |
cursor = i + 1; |
| 851 |
> |
lastRet = -1; |
| 852 |
> |
fence = outer.length; |
| 853 |
> |
expectedModCount = base.modCount; |
| 854 |
> |
} catch (IndexOutOfBoundsException ex) { |
| 855 |
> |
throw new ConcurrentModificationException(); |
| 856 |
> |
} |
| 857 |
> |
} |
| 858 |
|
} |
| 859 |
|
|
| 754 |
– |
private void checkForComodification() { |
| 755 |
– |
if (l.modCount != expectedModCount) |
| 756 |
– |
throw new ConcurrentModificationException(); |
| 757 |
– |
} |
| 860 |
|
} |
| 861 |
|
|
| 862 |
|
class RandomAccessSubList<E> extends SubList<E> implements RandomAccess { |
| 863 |
< |
RandomAccessSubList(AbstractList<E> list, int fromIndex, int toIndex) { |
| 864 |
< |
super(list, fromIndex, toIndex); |
| 863 |
> |
RandomAccessSubList(AbstractList<E> base, |
| 864 |
> |
AbstractList<E> parent, int baseIndex, |
| 865 |
> |
int fromIndex, int toIndex) { |
| 866 |
> |
super(base, parent, baseIndex, fromIndex, toIndex); |
| 867 |
|
} |
| 868 |
|
|
| 869 |
|
public List<E> subList(int fromIndex, int toIndex) { |
| 870 |
< |
return new RandomAccessSubList<E>(this, fromIndex, toIndex); |
| 870 |
> |
return new RandomAccessSubList(base, this, fromIndex + baseOffset, |
| 871 |
> |
fromIndex, toIndex); |
| 872 |
|
} |
| 873 |
|
} |
| 874 |
+ |
|
