J. Duke | 319a3b9 | 2007-12-01 00:00:00 +0000 | [diff] [blame^] | 1 | /* |
| 2 | * Copyright 1997-2007 Sun Microsystems, Inc. All Rights Reserved. |
| 3 | * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER. |
| 4 | * |
| 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 | * An ordered collection (also known as a <i>sequence</i>). The user of this |
| 30 | * interface has precise control over where in the list each element is |
| 31 | * inserted. The user can access elements by their integer index (position in |
| 32 | * the list), and search for elements in the list.<p> |
| 33 | * |
| 34 | * Unlike sets, lists typically allow duplicate elements. More formally, |
| 35 | * lists typically allow pairs of elements <tt>e1</tt> and <tt>e2</tt> |
| 36 | * such that <tt>e1.equals(e2)</tt>, and they typically allow multiple |
| 37 | * null elements if they allow null elements at all. It is not inconceivable |
| 38 | * that someone might wish to implement a list that prohibits duplicates, by |
| 39 | * throwing runtime exceptions when the user attempts to insert them, but we |
| 40 | * expect this usage to be rare.<p> |
| 41 | * |
| 42 | * The <tt>List</tt> interface places additional stipulations, beyond those |
| 43 | * specified in the <tt>Collection</tt> interface, on the contracts of the |
| 44 | * <tt>iterator</tt>, <tt>add</tt>, <tt>remove</tt>, <tt>equals</tt>, and |
| 45 | * <tt>hashCode</tt> methods. Declarations for other inherited methods are |
| 46 | * also included here for convenience.<p> |
| 47 | * |
| 48 | * The <tt>List</tt> interface provides four methods for positional (indexed) |
| 49 | * access to list elements. Lists (like Java arrays) are zero based. Note |
| 50 | * that these operations may execute in time proportional to the index value |
| 51 | * for some implementations (the <tt>LinkedList</tt> class, for |
| 52 | * example). Thus, iterating over the elements in a list is typically |
| 53 | * preferable to indexing through it if the caller does not know the |
| 54 | * implementation.<p> |
| 55 | * |
| 56 | * The <tt>List</tt> interface provides a special iterator, called a |
| 57 | * <tt>ListIterator</tt>, that allows element insertion and replacement, and |
| 58 | * bidirectional access in addition to the normal operations that the |
| 59 | * <tt>Iterator</tt> interface provides. A method is provided to obtain a |
| 60 | * list iterator that starts at a specified position in the list.<p> |
| 61 | * |
| 62 | * The <tt>List</tt> interface provides two methods to search for a specified |
| 63 | * object. From a performance standpoint, these methods should be used with |
| 64 | * caution. In many implementations they will perform costly linear |
| 65 | * searches.<p> |
| 66 | * |
| 67 | * The <tt>List</tt> interface provides two methods to efficiently insert and |
| 68 | * remove multiple elements at an arbitrary point in the list.<p> |
| 69 | * |
| 70 | * Note: While it is permissible for lists to contain themselves as elements, |
| 71 | * extreme caution is advised: the <tt>equals</tt> and <tt>hashCode</tt> |
| 72 | * methods are no longer well defined on such a list. |
| 73 | * |
| 74 | * <p>Some list implementations have restrictions on the elements that |
| 75 | * they may contain. For example, some implementations prohibit null elements, |
| 76 | * and some have restrictions on the types of their elements. Attempting to |
| 77 | * add an ineligible element throws an unchecked exception, typically |
| 78 | * <tt>NullPointerException</tt> or <tt>ClassCastException</tt>. Attempting |
| 79 | * to query the presence of an ineligible element may throw an exception, |
| 80 | * or it may simply return false; some implementations will exhibit the former |
| 81 | * behavior and some will exhibit the latter. More generally, attempting an |
| 82 | * operation on an ineligible element whose completion would not result in |
| 83 | * the insertion of an ineligible element into the list may throw an |
| 84 | * exception or it may succeed, at the option of the implementation. |
| 85 | * Such exceptions are marked as "optional" in the specification for this |
| 86 | * interface. |
| 87 | * |
| 88 | * <p>This interface is a member of the |
| 89 | * <a href="{@docRoot}/../technotes/guides/collections/index.html"> |
| 90 | * Java Collections Framework</a>. |
| 91 | * |
| 92 | * @author Josh Bloch |
| 93 | * @author Neal Gafter |
| 94 | * @see Collection |
| 95 | * @see Set |
| 96 | * @see ArrayList |
| 97 | * @see LinkedList |
| 98 | * @see Vector |
| 99 | * @see Arrays#asList(Object[]) |
| 100 | * @see Collections#nCopies(int, Object) |
| 101 | * @see Collections#EMPTY_LIST |
| 102 | * @see AbstractList |
| 103 | * @see AbstractSequentialList |
| 104 | * @since 1.2 |
| 105 | */ |
| 106 | |
| 107 | public interface List<E> extends Collection<E> { |
| 108 | // Query Operations |
| 109 | |
| 110 | /** |
| 111 | * Returns the number of elements in this list. If this list contains |
| 112 | * more than <tt>Integer.MAX_VALUE</tt> elements, returns |
| 113 | * <tt>Integer.MAX_VALUE</tt>. |
| 114 | * |
| 115 | * @return the number of elements in this list |
| 116 | */ |
| 117 | int size(); |
| 118 | |
| 119 | /** |
| 120 | * Returns <tt>true</tt> if this list contains no elements. |
| 121 | * |
| 122 | * @return <tt>true</tt> if this list contains no elements |
| 123 | */ |
| 124 | boolean isEmpty(); |
| 125 | |
| 126 | /** |
| 127 | * Returns <tt>true</tt> if this list contains the specified element. |
| 128 | * More formally, returns <tt>true</tt> if and only if this list contains |
| 129 | * at least one element <tt>e</tt> such that |
| 130 | * <tt>(o==null ? e==null : o.equals(e))</tt>. |
| 131 | * |
| 132 | * @param o element whose presence in this list is to be tested |
| 133 | * @return <tt>true</tt> if this list contains the specified element |
| 134 | * @throws ClassCastException if the type of the specified element |
| 135 | * is incompatible with this list (optional) |
| 136 | * @throws NullPointerException if the specified element is null and this |
| 137 | * list does not permit null elements (optional) |
| 138 | */ |
| 139 | boolean contains(Object o); |
| 140 | |
| 141 | /** |
| 142 | * Returns an iterator over the elements in this list in proper sequence. |
| 143 | * |
| 144 | * @return an iterator over the elements in this list in proper sequence |
| 145 | */ |
| 146 | Iterator<E> iterator(); |
| 147 | |
| 148 | /** |
| 149 | * Returns an array containing all of the elements in this list in proper |
| 150 | * sequence (from first to last element). |
| 151 | * |
| 152 | * <p>The returned array will be "safe" in that no references to it are |
| 153 | * maintained by this list. (In other words, this method must |
| 154 | * allocate a new array even if this list is backed by an array). |
| 155 | * The caller is thus free to modify the returned array. |
| 156 | * |
| 157 | * <p>This method acts as bridge between array-based and collection-based |
| 158 | * APIs. |
| 159 | * |
| 160 | * @return an array containing all of the elements in this list in proper |
| 161 | * sequence |
| 162 | * @see Arrays#asList(Object[]) |
| 163 | */ |
| 164 | Object[] toArray(); |
| 165 | |
| 166 | /** |
| 167 | * Returns an array containing all of the elements in this list in |
| 168 | * proper sequence (from first to last element); the runtime type of |
| 169 | * the returned array is that of the specified array. If the list fits |
| 170 | * in the specified array, it is returned therein. Otherwise, a new |
| 171 | * array is allocated with the runtime type of the specified array and |
| 172 | * the size of this list. |
| 173 | * |
| 174 | * <p>If the list fits in the specified array with room to spare (i.e., |
| 175 | * the array has more elements than the list), the element in the array |
| 176 | * immediately following the end of the list is set to <tt>null</tt>. |
| 177 | * (This is useful in determining the length of the list <i>only</i> if |
| 178 | * the caller knows that the list does not contain any null elements.) |
| 179 | * |
| 180 | * <p>Like the {@link #toArray()} method, this method acts as bridge between |
| 181 | * array-based and collection-based APIs. Further, this method allows |
| 182 | * precise control over the runtime type of the output array, and may, |
| 183 | * under certain circumstances, be used to save allocation costs. |
| 184 | * |
| 185 | * <p>Suppose <tt>x</tt> is a list known to contain only strings. |
| 186 | * The following code can be used to dump the list into a newly |
| 187 | * allocated array of <tt>String</tt>: |
| 188 | * |
| 189 | * <pre> |
| 190 | * String[] y = x.toArray(new String[0]);</pre> |
| 191 | * |
| 192 | * Note that <tt>toArray(new Object[0])</tt> is identical in function to |
| 193 | * <tt>toArray()</tt>. |
| 194 | * |
| 195 | * @param a the array into which the elements of this list are to |
| 196 | * be stored, if it is big enough; otherwise, a new array of the |
| 197 | * same runtime type is allocated for this purpose. |
| 198 | * @return an array containing the elements of this list |
| 199 | * @throws ArrayStoreException if the runtime type of the specified array |
| 200 | * is not a supertype of the runtime type of every element in |
| 201 | * this list |
| 202 | * @throws NullPointerException if the specified array is null |
| 203 | */ |
| 204 | <T> T[] toArray(T[] a); |
| 205 | |
| 206 | |
| 207 | // Modification Operations |
| 208 | |
| 209 | /** |
| 210 | * Appends the specified element to the end of this list (optional |
| 211 | * operation). |
| 212 | * |
| 213 | * <p>Lists that support this operation may place limitations on what |
| 214 | * elements may be added to this list. In particular, some |
| 215 | * lists will refuse to add null elements, and others will impose |
| 216 | * restrictions on the type of elements that may be added. List |
| 217 | * classes should clearly specify in their documentation any restrictions |
| 218 | * on what elements may be added. |
| 219 | * |
| 220 | * @param e element to be appended to this list |
| 221 | * @return <tt>true</tt> (as specified by {@link Collection#add}) |
| 222 | * @throws UnsupportedOperationException if the <tt>add</tt> operation |
| 223 | * is not supported by this list |
| 224 | * @throws ClassCastException if the class of the specified element |
| 225 | * prevents it from being added to this list |
| 226 | * @throws NullPointerException if the specified element is null and this |
| 227 | * list does not permit null elements |
| 228 | * @throws IllegalArgumentException if some property of this element |
| 229 | * prevents it from being added to this list |
| 230 | */ |
| 231 | boolean add(E e); |
| 232 | |
| 233 | /** |
| 234 | * Removes the first occurrence of the specified element from this list, |
| 235 | * if it is present (optional operation). If this list does not contain |
| 236 | * the element, it is unchanged. More formally, removes the element with |
| 237 | * the lowest index <tt>i</tt> such that |
| 238 | * <tt>(o==null ? get(i)==null : o.equals(get(i)))</tt> |
| 239 | * (if such an element exists). Returns <tt>true</tt> if this list |
| 240 | * contained the specified element (or equivalently, if this list changed |
| 241 | * as a result of the call). |
| 242 | * |
| 243 | * @param o element to be removed from this list, if present |
| 244 | * @return <tt>true</tt> if this list contained the specified element |
| 245 | * @throws ClassCastException if the type of the specified element |
| 246 | * is incompatible with this list (optional) |
| 247 | * @throws NullPointerException if the specified element is null and this |
| 248 | * list does not permit null elements (optional) |
| 249 | * @throws UnsupportedOperationException if the <tt>remove</tt> operation |
| 250 | * is not supported by this list |
| 251 | */ |
| 252 | boolean remove(Object o); |
| 253 | |
| 254 | |
| 255 | // Bulk Modification Operations |
| 256 | |
| 257 | /** |
| 258 | * Returns <tt>true</tt> if this list contains all of the elements of the |
| 259 | * specified collection. |
| 260 | * |
| 261 | * @param c collection to be checked for containment in this list |
| 262 | * @return <tt>true</tt> if this list contains all of the elements of the |
| 263 | * specified collection |
| 264 | * @throws ClassCastException if the types of one or more elements |
| 265 | * in the specified collection are incompatible with this |
| 266 | * list (optional) |
| 267 | * @throws NullPointerException if the specified collection contains one |
| 268 | * or more null elements and this list does not permit null |
| 269 | * elements (optional), or if the specified collection is null |
| 270 | * @see #contains(Object) |
| 271 | */ |
| 272 | boolean containsAll(Collection<?> c); |
| 273 | |
| 274 | /** |
| 275 | * Appends all of the elements in the specified collection to the end of |
| 276 | * this list, in the order that they are returned by the specified |
| 277 | * collection's iterator (optional operation). The behavior of this |
| 278 | * operation is undefined if the specified collection is modified while |
| 279 | * the operation is in progress. (Note that this will occur if the |
| 280 | * specified collection is this list, and it's nonempty.) |
| 281 | * |
| 282 | * @param c collection containing elements to be added to this list |
| 283 | * @return <tt>true</tt> if this list changed as a result of the call |
| 284 | * @throws UnsupportedOperationException if the <tt>addAll</tt> operation |
| 285 | * is not supported by this list |
| 286 | * @throws ClassCastException if the class of an element of the specified |
| 287 | * collection prevents it from being added to this list |
| 288 | * @throws NullPointerException if the specified collection contains one |
| 289 | * or more null elements and this list does not permit null |
| 290 | * elements, or if the specified collection is null |
| 291 | * @throws IllegalArgumentException if some property of an element of the |
| 292 | * specified collection prevents it from being added to this list |
| 293 | * @see #add(Object) |
| 294 | */ |
| 295 | boolean addAll(Collection<? extends E> c); |
| 296 | |
| 297 | /** |
| 298 | * Inserts all of the elements in the specified collection into this |
| 299 | * list at the specified position (optional operation). Shifts the |
| 300 | * element currently at that position (if any) and any subsequent |
| 301 | * elements to the right (increases their indices). The new elements |
| 302 | * will appear in this list in the order that they are returned by the |
| 303 | * specified collection's iterator. The behavior of this operation is |
| 304 | * undefined if the specified collection is modified while the |
| 305 | * operation is in progress. (Note that this will occur if the specified |
| 306 | * collection is this list, and it's nonempty.) |
| 307 | * |
| 308 | * @param index index at which to insert the first element from the |
| 309 | * specified collection |
| 310 | * @param c collection containing elements to be added to this list |
| 311 | * @return <tt>true</tt> if this list changed as a result of the call |
| 312 | * @throws UnsupportedOperationException if the <tt>addAll</tt> operation |
| 313 | * is not supported by this list |
| 314 | * @throws ClassCastException if the class of an element of the specified |
| 315 | * collection prevents it from being added to this list |
| 316 | * @throws NullPointerException if the specified collection contains one |
| 317 | * or more null elements and this list does not permit null |
| 318 | * elements, or if the specified collection is null |
| 319 | * @throws IllegalArgumentException if some property of an element of the |
| 320 | * specified collection prevents it from being added to this list |
| 321 | * @throws IndexOutOfBoundsException if the index is out of range |
| 322 | * (<tt>index < 0 || index > size()</tt>) |
| 323 | */ |
| 324 | boolean addAll(int index, Collection<? extends E> c); |
| 325 | |
| 326 | /** |
| 327 | * Removes from this list all of its elements that are contained in the |
| 328 | * specified collection (optional operation). |
| 329 | * |
| 330 | * @param c collection containing elements to be removed from this list |
| 331 | * @return <tt>true</tt> if this list changed as a result of the call |
| 332 | * @throws UnsupportedOperationException if the <tt>removeAll</tt> operation |
| 333 | * is not supported by this list |
| 334 | * @throws ClassCastException if the class of an element of this list |
| 335 | * is incompatible with the specified collection (optional) |
| 336 | * @throws NullPointerException if this list contains a null element and the |
| 337 | * specified collection does not permit null elements (optional), |
| 338 | * or if the specified collection is null |
| 339 | * @see #remove(Object) |
| 340 | * @see #contains(Object) |
| 341 | */ |
| 342 | boolean removeAll(Collection<?> c); |
| 343 | |
| 344 | /** |
| 345 | * Retains only the elements in this list that are contained in the |
| 346 | * specified collection (optional operation). In other words, removes |
| 347 | * from this list all of its elements that are not contained in the |
| 348 | * specified collection. |
| 349 | * |
| 350 | * @param c collection containing elements to be retained in this list |
| 351 | * @return <tt>true</tt> if this list changed as a result of the call |
| 352 | * @throws UnsupportedOperationException if the <tt>retainAll</tt> operation |
| 353 | * is not supported by this list |
| 354 | * @throws ClassCastException if the class of an element of this list |
| 355 | * is incompatible with the specified collection (optional) |
| 356 | * @throws NullPointerException if this list contains a null element and the |
| 357 | * specified collection does not permit null elements (optional), |
| 358 | * or if the specified collection is null |
| 359 | * @see #remove(Object) |
| 360 | * @see #contains(Object) |
| 361 | */ |
| 362 | boolean retainAll(Collection<?> c); |
| 363 | |
| 364 | /** |
| 365 | * Removes all of the elements from this list (optional operation). |
| 366 | * The list will be empty after this call returns. |
| 367 | * |
| 368 | * @throws UnsupportedOperationException if the <tt>clear</tt> operation |
| 369 | * is not supported by this list |
| 370 | */ |
| 371 | void clear(); |
| 372 | |
| 373 | |
| 374 | // Comparison and hashing |
| 375 | |
| 376 | /** |
| 377 | * Compares the specified object with this list for equality. Returns |
| 378 | * <tt>true</tt> if and only if the specified object is also a list, both |
| 379 | * lists have the same size, and all corresponding pairs of elements in |
| 380 | * the two lists are <i>equal</i>. (Two elements <tt>e1</tt> and |
| 381 | * <tt>e2</tt> are <i>equal</i> if <tt>(e1==null ? e2==null : |
| 382 | * e1.equals(e2))</tt>.) In other words, two lists are defined to be |
| 383 | * equal if they contain the same elements in the same order. This |
| 384 | * definition ensures that the equals method works properly across |
| 385 | * different implementations of the <tt>List</tt> interface. |
| 386 | * |
| 387 | * @param o the object to be compared for equality with this list |
| 388 | * @return <tt>true</tt> if the specified object is equal to this list |
| 389 | */ |
| 390 | boolean equals(Object o); |
| 391 | |
| 392 | /** |
| 393 | * Returns the hash code value for this list. The hash code of a list |
| 394 | * is defined to be the result of the following calculation: |
| 395 | * <pre> |
| 396 | * int hashCode = 1; |
| 397 | * for (E e : list) |
| 398 | * hashCode = 31*hashCode + (e==null ? 0 : e.hashCode()); |
| 399 | * </pre> |
| 400 | * This ensures that <tt>list1.equals(list2)</tt> implies that |
| 401 | * <tt>list1.hashCode()==list2.hashCode()</tt> for any two lists, |
| 402 | * <tt>list1</tt> and <tt>list2</tt>, as required by the general |
| 403 | * contract of {@link Object#hashCode}. |
| 404 | * |
| 405 | * @return the hash code value for this list |
| 406 | * @see Object#equals(Object) |
| 407 | * @see #equals(Object) |
| 408 | */ |
| 409 | int hashCode(); |
| 410 | |
| 411 | |
| 412 | // Positional Access Operations |
| 413 | |
| 414 | /** |
| 415 | * Returns the element at the specified position in this list. |
| 416 | * |
| 417 | * @param index index of the element to return |
| 418 | * @return the element at the specified position in this list |
| 419 | * @throws IndexOutOfBoundsException if the index is out of range |
| 420 | * (<tt>index < 0 || index >= size()</tt>) |
| 421 | */ |
| 422 | E get(int index); |
| 423 | |
| 424 | /** |
| 425 | * Replaces the element at the specified position in this list with the |
| 426 | * specified element (optional operation). |
| 427 | * |
| 428 | * @param index index of the element to replace |
| 429 | * @param element element to be stored at the specified position |
| 430 | * @return the element previously at the specified position |
| 431 | * @throws UnsupportedOperationException if the <tt>set</tt> operation |
| 432 | * is not supported by this list |
| 433 | * @throws ClassCastException if the class of the specified element |
| 434 | * prevents it from being added to this list |
| 435 | * @throws NullPointerException if the specified element is null and |
| 436 | * this list does not permit null elements |
| 437 | * @throws IllegalArgumentException if some property of the specified |
| 438 | * element prevents it from being added to this list |
| 439 | * @throws IndexOutOfBoundsException if the index is out of range |
| 440 | * (<tt>index < 0 || index >= size()</tt>) |
| 441 | */ |
| 442 | E set(int index, E element); |
| 443 | |
| 444 | /** |
| 445 | * Inserts the specified element at the specified position in this list |
| 446 | * (optional operation). Shifts the element currently at that position |
| 447 | * (if any) and any subsequent elements to the right (adds one to their |
| 448 | * indices). |
| 449 | * |
| 450 | * @param index index at which the specified element is to be inserted |
| 451 | * @param element element to be inserted |
| 452 | * @throws UnsupportedOperationException if the <tt>add</tt> operation |
| 453 | * is not supported by this list |
| 454 | * @throws ClassCastException if the class of the specified element |
| 455 | * prevents it from being added to this list |
| 456 | * @throws NullPointerException if the specified element is null and |
| 457 | * this list does not permit null elements |
| 458 | * @throws IllegalArgumentException if some property of the specified |
| 459 | * element prevents it from being added to this list |
| 460 | * @throws IndexOutOfBoundsException if the index is out of range |
| 461 | * (<tt>index < 0 || index > size()</tt>) |
| 462 | */ |
| 463 | void add(int index, E element); |
| 464 | |
| 465 | /** |
| 466 | * Removes the element at the specified position in this list (optional |
| 467 | * operation). Shifts any subsequent elements to the left (subtracts one |
| 468 | * from their indices). Returns the element that was removed from the |
| 469 | * list. |
| 470 | * |
| 471 | * @param index the index of the element to be removed |
| 472 | * @return the element previously at the specified position |
| 473 | * @throws UnsupportedOperationException if the <tt>remove</tt> operation |
| 474 | * is not supported by this list |
| 475 | * @throws IndexOutOfBoundsException if the index is out of range |
| 476 | * (<tt>index < 0 || index >= size()</tt>) |
| 477 | */ |
| 478 | E remove(int index); |
| 479 | |
| 480 | |
| 481 | // Search Operations |
| 482 | |
| 483 | /** |
| 484 | * Returns the index of the first occurrence of the specified element |
| 485 | * in this list, or -1 if this list does not contain the element. |
| 486 | * More formally, returns the lowest index <tt>i</tt> such that |
| 487 | * <tt>(o==null ? get(i)==null : o.equals(get(i)))</tt>, |
| 488 | * or -1 if there is no such index. |
| 489 | * |
| 490 | * @param o element to search for |
| 491 | * @return the index of the first occurrence of the specified element in |
| 492 | * this list, or -1 if this list does not contain the element |
| 493 | * @throws ClassCastException if the type of the specified element |
| 494 | * is incompatible with this list (optional) |
| 495 | * @throws NullPointerException if the specified element is null and this |
| 496 | * list does not permit null elements (optional) |
| 497 | */ |
| 498 | int indexOf(Object o); |
| 499 | |
| 500 | /** |
| 501 | * Returns the index of the last occurrence of the specified element |
| 502 | * in this list, or -1 if this list does not contain the element. |
| 503 | * More formally, returns the highest index <tt>i</tt> such that |
| 504 | * <tt>(o==null ? get(i)==null : o.equals(get(i)))</tt>, |
| 505 | * or -1 if there is no such index. |
| 506 | * |
| 507 | * @param o element to search for |
| 508 | * @return the index of the last occurrence of the specified element in |
| 509 | * this list, or -1 if this list does not contain the element |
| 510 | * @throws ClassCastException if the type of the specified element |
| 511 | * is incompatible with this list (optional) |
| 512 | * @throws NullPointerException if the specified element is null and this |
| 513 | * list does not permit null elements (optional) |
| 514 | */ |
| 515 | int lastIndexOf(Object o); |
| 516 | |
| 517 | |
| 518 | // List Iterators |
| 519 | |
| 520 | /** |
| 521 | * Returns a list iterator over the elements in this list (in proper |
| 522 | * sequence). |
| 523 | * |
| 524 | * @return a list iterator over the elements in this list (in proper |
| 525 | * sequence) |
| 526 | */ |
| 527 | ListIterator<E> listIterator(); |
| 528 | |
| 529 | /** |
| 530 | * Returns a list iterator over the elements in this list (in proper |
| 531 | * sequence), starting at the specified position in the list. |
| 532 | * The specified index indicates the first element that would be |
| 533 | * returned by an initial call to {@link ListIterator#next next}. |
| 534 | * An initial call to {@link ListIterator#previous previous} would |
| 535 | * return the element with the specified index minus one. |
| 536 | * |
| 537 | * @param index index of the first element to be returned from the |
| 538 | * list iterator (by a call to {@link ListIterator#next next}) |
| 539 | * @return a list iterator over the elements in this list (in proper |
| 540 | * sequence), starting at the specified position in the list |
| 541 | * @throws IndexOutOfBoundsException if the index is out of range |
| 542 | * ({@code index < 0 || index > size()}) |
| 543 | */ |
| 544 | ListIterator<E> listIterator(int index); |
| 545 | |
| 546 | // View |
| 547 | |
| 548 | /** |
| 549 | * Returns a view of the portion of this list between the specified |
| 550 | * <tt>fromIndex</tt>, inclusive, and <tt>toIndex</tt>, exclusive. (If |
| 551 | * <tt>fromIndex</tt> and <tt>toIndex</tt> are equal, the returned list is |
| 552 | * empty.) The returned list is backed by this list, so non-structural |
| 553 | * changes in the returned list are reflected in this list, and vice-versa. |
| 554 | * The returned list supports all of the optional list operations supported |
| 555 | * by this list.<p> |
| 556 | * |
| 557 | * This method eliminates the need for explicit range operations (of |
| 558 | * the sort that commonly exist for arrays). Any operation that expects |
| 559 | * a list can be used as a range operation by passing a subList view |
| 560 | * instead of a whole list. For example, the following idiom |
| 561 | * removes a range of elements from a list: |
| 562 | * <pre> |
| 563 | * list.subList(from, to).clear(); |
| 564 | * </pre> |
| 565 | * Similar idioms may be constructed for <tt>indexOf</tt> and |
| 566 | * <tt>lastIndexOf</tt>, and all of the algorithms in the |
| 567 | * <tt>Collections</tt> class can be applied to a subList.<p> |
| 568 | * |
| 569 | * The semantics of the list returned by this method become undefined if |
| 570 | * the backing list (i.e., this list) is <i>structurally modified</i> in |
| 571 | * any way other than via the returned list. (Structural modifications are |
| 572 | * those that change the size of this list, or otherwise perturb it in such |
| 573 | * a fashion that iterations in progress may yield incorrect results.) |
| 574 | * |
| 575 | * @param fromIndex low endpoint (inclusive) of the subList |
| 576 | * @param toIndex high endpoint (exclusive) of the subList |
| 577 | * @return a view of the specified range within this list |
| 578 | * @throws IndexOutOfBoundsException for an illegal endpoint index value |
| 579 | * (<tt>fromIndex < 0 || toIndex > size || |
| 580 | * fromIndex > toIndex</tt>) |
| 581 | */ |
| 582 | List<E> subList(int fromIndex, int toIndex); |
| 583 | } |