1 /* 2 * Copyright (C) 2014 The Android Open Source Project 3 * Copyright (c) 2003, 2010, Oracle and/or its affiliates. All rights reserved. 4 * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER. 5 * 6 * This code is free software; you can redistribute it and/or modify it 7 * under the terms of the GNU General Public License version 2 only, as 8 * published by the Free Software Foundation. Oracle designates this 9 * particular file as subject to the "Classpath" exception as provided 10 * by Oracle in the LICENSE file that accompanied this code. 11 * 12 * This code is distributed in the hope that it will be useful, but WITHOUT 13 * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or 14 * FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License 15 * version 2 for more details (a copy is included in the LICENSE file that 16 * accompanied this code). 17 * 18 * You should have received a copy of the GNU General Public License version 19 * 2 along with this work; if not, write to the Free Software Foundation, 20 * Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA. 21 * 22 * Please contact Oracle, 500 Oracle Parkway, Redwood Shores, CA 94065 USA 23 * or visit www.oracle.com if you need additional information or have any 24 * questions. 25 */ 26 27 package java.lang; 28 29 import java.util.Arrays; 30 31 /** 32 * A mutable sequence of characters. 33 * <p> 34 * Implements a modifiable string. At any point in time it contains some 35 * particular sequence of characters, but the length and content of the 36 * sequence can be changed through certain method calls. 37 * 38 * @author Michael McCloskey 39 * @author Martin Buchholz 40 * @author Ulf Zibis 41 * @since 1.5 42 */ 43 abstract class AbstractStringBuilder implements CharSequence { 44 /** 45 * The value is used for character storage. 46 */ 47 char[] value; 48 49 /** 50 * The count is the number of characters used. 51 */ 52 int count; 53 54 /** 55 * This no-arg constructor is necessary for serialization of subclasses. 56 */ AbstractStringBuilder()57 AbstractStringBuilder() { 58 } 59 60 /** 61 * Creates an AbstractStringBuilder of the specified capacity. 62 */ AbstractStringBuilder(int capacity)63 AbstractStringBuilder(int capacity) { 64 value = new char[capacity]; 65 } 66 67 /** 68 * Returns the length (character count). 69 * 70 * @return the length of the sequence of characters currently 71 * represented by this object 72 */ length()73 public int length() { 74 return count; 75 } 76 77 /** 78 * Returns the current capacity. The capacity is the amount of storage 79 * available for newly inserted characters, beyond which an allocation 80 * will occur. 81 * 82 * @return the current capacity 83 */ capacity()84 public int capacity() { 85 return value.length; 86 } 87 88 /** 89 * Ensures that the capacity is at least equal to the specified minimum. 90 * If the current capacity is less than the argument, then a new internal 91 * array is allocated with greater capacity. The new capacity is the 92 * larger of: 93 * <ul> 94 * <li>The <code>minimumCapacity</code> argument. 95 * <li>Twice the old capacity, plus <code>2</code>. 96 * </ul> 97 * If the <code>minimumCapacity</code> argument is nonpositive, this 98 * method takes no action and simply returns. 99 * 100 * @param minimumCapacity the minimum desired capacity. 101 */ ensureCapacity(int minimumCapacity)102 public void ensureCapacity(int minimumCapacity) { 103 if (minimumCapacity > 0) 104 ensureCapacityInternal(minimumCapacity); 105 } 106 107 /** 108 * This method has the same contract as ensureCapacity, but is 109 * never synchronized. 110 */ ensureCapacityInternal(int minimumCapacity)111 void ensureCapacityInternal(int minimumCapacity) { 112 // overflow-conscious code 113 if (minimumCapacity - value.length > 0) 114 expandCapacity(minimumCapacity); 115 } 116 117 /** 118 * This implements the expansion semantics of ensureCapacity with no 119 * size check or synchronization. 120 */ expandCapacity(int minimumCapacity)121 void expandCapacity(int minimumCapacity) { 122 int newCapacity = value.length * 2 + 2; 123 if (newCapacity - minimumCapacity < 0) 124 newCapacity = minimumCapacity; 125 if (newCapacity < 0) { 126 if (minimumCapacity < 0) // overflow 127 throw new OutOfMemoryError(); 128 newCapacity = Integer.MAX_VALUE; 129 } 130 value = Arrays.copyOf(value, newCapacity); 131 } 132 133 /** 134 * Attempts to reduce storage used for the character sequence. 135 * If the buffer is larger than necessary to hold its current sequence of 136 * characters, then it may be resized to become more space efficient. 137 * Calling this method may, but is not required to, affect the value 138 * returned by a subsequent call to the {@link #capacity()} method. 139 */ trimToSize()140 public void trimToSize() { 141 if (count < value.length) { 142 value = Arrays.copyOf(value, count); 143 } 144 } 145 146 /** 147 * Sets the length of the character sequence. 148 * The sequence is changed to a new character sequence 149 * whose length is specified by the argument. For every nonnegative 150 * index <i>k</i> less than <code>newLength</code>, the character at 151 * index <i>k</i> in the new character sequence is the same as the 152 * character at index <i>k</i> in the old sequence if <i>k</i> is less 153 * than the length of the old character sequence; otherwise, it is the 154 * null character <code>'\u0000'</code>. 155 * 156 * In other words, if the <code>newLength</code> argument is less than 157 * the current length, the length is changed to the specified length. 158 * <p> 159 * If the <code>newLength</code> argument is greater than or equal 160 * to the current length, sufficient null characters 161 * (<code>'\u0000'</code>) are appended so that 162 * length becomes the <code>newLength</code> argument. 163 * <p> 164 * The <code>newLength</code> argument must be greater than or equal 165 * to <code>0</code>. 166 * 167 * @param newLength the new length 168 * @throws IndexOutOfBoundsException if the 169 * <code>newLength</code> argument is negative. 170 */ setLength(int newLength)171 public void setLength(int newLength) { 172 if (newLength < 0) 173 throw new StringIndexOutOfBoundsException(newLength); 174 ensureCapacityInternal(newLength); 175 176 if (count < newLength) { 177 for (; count < newLength; count++) 178 value[count] = '\0'; 179 } else { 180 count = newLength; 181 } 182 } 183 184 /** 185 * Returns the <code>char</code> value in this sequence at the specified index. 186 * The first <code>char</code> value is at index <code>0</code>, the next at index 187 * <code>1</code>, and so on, as in array indexing. 188 * <p> 189 * The index argument must be greater than or equal to 190 * <code>0</code>, and less than the length of this sequence. 191 * 192 * <p>If the <code>char</code> value specified by the index is a 193 * <a href="Character.html#unicode">surrogate</a>, the surrogate 194 * value is returned. 195 * 196 * @param index the index of the desired <code>char</code> value. 197 * @return the <code>char</code> value at the specified index. 198 * @throws IndexOutOfBoundsException if <code>index</code> is 199 * negative or greater than or equal to <code>length()</code>. 200 */ charAt(int index)201 public char charAt(int index) { 202 if ((index < 0) || (index >= count)) 203 throw new StringIndexOutOfBoundsException(index); 204 return value[index]; 205 } 206 207 /** 208 * Returns the character (Unicode code point) at the specified 209 * index. The index refers to <code>char</code> values 210 * (Unicode code units) and ranges from <code>0</code> to 211 * {@link #length()}<code> - 1</code>. 212 * 213 * <p> If the <code>char</code> value specified at the given index 214 * is in the high-surrogate range, the following index is less 215 * than the length of this sequence, and the 216 * <code>char</code> value at the following index is in the 217 * low-surrogate range, then the supplementary code point 218 * corresponding to this surrogate pair is returned. Otherwise, 219 * the <code>char</code> value at the given index is returned. 220 * 221 * @param index the index to the <code>char</code> values 222 * @return the code point value of the character at the 223 * <code>index</code> 224 * @exception IndexOutOfBoundsException if the <code>index</code> 225 * argument is negative or not less than the length of this 226 * sequence. 227 */ codePointAt(int index)228 public int codePointAt(int index) { 229 if ((index < 0) || (index >= count)) { 230 throw new StringIndexOutOfBoundsException(index); 231 } 232 return Character.codePointAt(value, index); 233 } 234 235 /** 236 * Returns the character (Unicode code point) before the specified 237 * index. The index refers to <code>char</code> values 238 * (Unicode code units) and ranges from <code>1</code> to {@link 239 * #length()}. 240 * 241 * <p> If the <code>char</code> value at <code>(index - 1)</code> 242 * is in the low-surrogate range, <code>(index - 2)</code> is not 243 * negative, and the <code>char</code> value at <code>(index - 244 * 2)</code> is in the high-surrogate range, then the 245 * supplementary code point value of the surrogate pair is 246 * returned. If the <code>char</code> value at <code>index - 247 * 1</code> is an unpaired low-surrogate or a high-surrogate, the 248 * surrogate value is returned. 249 * 250 * @param index the index following the code point that should be returned 251 * @return the Unicode code point value before the given index. 252 * @exception IndexOutOfBoundsException if the <code>index</code> 253 * argument is less than 1 or greater than the length 254 * of this sequence. 255 */ codePointBefore(int index)256 public int codePointBefore(int index) { 257 int i = index - 1; 258 if ((i < 0) || (i >= count)) { 259 throw new StringIndexOutOfBoundsException(index); 260 } 261 return Character.codePointBefore(value, index); 262 } 263 264 /** 265 * Returns the number of Unicode code points in the specified text 266 * range of this sequence. The text range begins at the specified 267 * <code>beginIndex</code> and extends to the <code>char</code> at 268 * index <code>endIndex - 1</code>. Thus the length (in 269 * <code>char</code>s) of the text range is 270 * <code>endIndex-beginIndex</code>. Unpaired surrogates within 271 * this sequence count as one code point each. 272 * 273 * @param beginIndex the index to the first <code>char</code> of 274 * the text range. 275 * @param endIndex the index after the last <code>char</code> of 276 * the text range. 277 * @return the number of Unicode code points in the specified text 278 * range 279 * @exception IndexOutOfBoundsException if the 280 * <code>beginIndex</code> is negative, or <code>endIndex</code> 281 * is larger than the length of this sequence, or 282 * <code>beginIndex</code> is larger than <code>endIndex</code>. 283 */ codePointCount(int beginIndex, int endIndex)284 public int codePointCount(int beginIndex, int endIndex) { 285 if (beginIndex < 0 || endIndex > count || beginIndex > endIndex) { 286 throw new IndexOutOfBoundsException(); 287 } 288 return Character.codePointCountImpl(value, beginIndex, endIndex-beginIndex); 289 } 290 291 /** 292 * Returns the index within this sequence that is offset from the 293 * given <code>index</code> by <code>codePointOffset</code> code 294 * points. Unpaired surrogates within the text range given by 295 * <code>index</code> and <code>codePointOffset</code> count as 296 * one code point each. 297 * 298 * @param index the index to be offset 299 * @param codePointOffset the offset in code points 300 * @return the index within this sequence 301 * @exception IndexOutOfBoundsException if <code>index</code> 302 * is negative or larger then the length of this sequence, 303 * or if <code>codePointOffset</code> is positive and the subsequence 304 * starting with <code>index</code> has fewer than 305 * <code>codePointOffset</code> code points, 306 * or if <code>codePointOffset</code> is negative and the subsequence 307 * before <code>index</code> has fewer than the absolute value of 308 * <code>codePointOffset</code> code points. 309 */ offsetByCodePoints(int index, int codePointOffset)310 public int offsetByCodePoints(int index, int codePointOffset) { 311 if (index < 0 || index > count) { 312 throw new IndexOutOfBoundsException(); 313 } 314 return Character.offsetByCodePointsImpl(value, 0, count, 315 index, codePointOffset); 316 } 317 318 /** 319 * Characters are copied from this sequence into the 320 * destination character array <code>dst</code>. The first character to 321 * be copied is at index <code>srcBegin</code>; the last character to 322 * be copied is at index <code>srcEnd-1</code>. The total number of 323 * characters to be copied is <code>srcEnd-srcBegin</code>. The 324 * characters are copied into the subarray of <code>dst</code> starting 325 * at index <code>dstBegin</code> and ending at index: 326 * <p><blockquote><pre> 327 * dstbegin + (srcEnd-srcBegin) - 1 328 * </pre></blockquote> 329 * 330 * @param srcBegin start copying at this offset. 331 * @param srcEnd stop copying at this offset. 332 * @param dst the array to copy the data into. 333 * @param dstBegin offset into <code>dst</code>. 334 * @throws NullPointerException if <code>dst</code> is 335 * <code>null</code>. 336 * @throws IndexOutOfBoundsException if any of the following is true: 337 * <ul> 338 * <li><code>srcBegin</code> is negative 339 * <li><code>dstBegin</code> is negative 340 * <li>the <code>srcBegin</code> argument is greater than 341 * the <code>srcEnd</code> argument. 342 * <li><code>srcEnd</code> is greater than 343 * <code>this.length()</code>. 344 * <li><code>dstBegin+srcEnd-srcBegin</code> is greater than 345 * <code>dst.length</code> 346 * </ul> 347 */ getChars(int srcBegin, int srcEnd, char[] dst, int dstBegin)348 public void getChars(int srcBegin, int srcEnd, char[] dst, int dstBegin) 349 { 350 if (srcBegin < 0) 351 throw new StringIndexOutOfBoundsException(srcBegin); 352 if ((srcEnd < 0) || (srcEnd > count)) 353 throw new StringIndexOutOfBoundsException(srcEnd); 354 if (srcBegin > srcEnd) 355 throw new StringIndexOutOfBoundsException("srcBegin > srcEnd"); 356 System.arraycopy(value, srcBegin, dst, dstBegin, srcEnd - srcBegin); 357 } 358 359 /** 360 * The character at the specified index is set to <code>ch</code>. This 361 * sequence is altered to represent a new character sequence that is 362 * identical to the old character sequence, except that it contains the 363 * character <code>ch</code> at position <code>index</code>. 364 * <p> 365 * The index argument must be greater than or equal to 366 * <code>0</code>, and less than the length of this sequence. 367 * 368 * @param index the index of the character to modify. 369 * @param ch the new character. 370 * @throws IndexOutOfBoundsException if <code>index</code> is 371 * negative or greater than or equal to <code>length()</code>. 372 */ setCharAt(int index, char ch)373 public void setCharAt(int index, char ch) { 374 if ((index < 0) || (index >= count)) 375 throw new StringIndexOutOfBoundsException(index); 376 value[index] = ch; 377 } 378 379 /** 380 * Appends the string representation of the {@code Object} argument. 381 * <p> 382 * The overall effect is exactly as if the argument were converted 383 * to a string by the method {@link String#valueOf(Object)}, 384 * and the characters of that string were then 385 * {@link #append(String) appended} to this character sequence. 386 * 387 * @param obj an {@code Object}. 388 * @return a reference to this object. 389 * @hide 390 */ append(Object obj)391 public AbstractStringBuilder append(Object obj) { 392 return append(String.valueOf(obj)); 393 } 394 395 /** 396 * Appends the specified string to this character sequence. 397 * <p> 398 * The characters of the {@code String} argument are appended, in 399 * order, increasing the length of this sequence by the length of the 400 * argument. If {@code str} is {@code null}, then the four 401 * characters {@code "null"} are appended. 402 * <p> 403 * Let <i>n</i> be the length of this character sequence just prior to 404 * execution of the {@code append} method. Then the character at 405 * index <i>k</i> in the new character sequence is equal to the character 406 * at index <i>k</i> in the old character sequence, if <i>k</i> is less 407 * than <i>n</i>; otherwise, it is equal to the character at index 408 * <i>k-n</i> in the argument {@code str}. 409 * 410 * @param str a string. 411 * @return a reference to this object. 412 * @hide 413 */ append(String str)414 public AbstractStringBuilder append(String str) { 415 if (str == null) str = "null"; 416 int len = str.length(); 417 ensureCapacityInternal(count + len); 418 str.getCharsNoCheck(0, len, value, count); 419 count += len; 420 return this; 421 } 422 423 // Documentation in subclasses because of synchro difference 424 /** @hide */ append(StringBuffer sb)425 public AbstractStringBuilder append(StringBuffer sb) { 426 if (sb == null) 427 return append("null"); 428 int len = sb.length(); 429 ensureCapacityInternal(count + len); 430 sb.getChars(0, len, value, count); 431 count += len; 432 return this; 433 } 434 435 // Documentation in subclasses because of synchro difference 436 /** @hide */ append(CharSequence s)437 public AbstractStringBuilder append(CharSequence s) { 438 if (s == null) 439 s = "null"; 440 if (s instanceof String) 441 return this.append((String)s); 442 if (s instanceof StringBuffer) 443 return this.append((StringBuffer)s); 444 return this.append(s, 0, s.length()); 445 } 446 447 /** 448 * Appends a subsequence of the specified {@code CharSequence} to this 449 * sequence. 450 * <p> 451 * Characters of the argument {@code s}, starting at 452 * index {@code start}, are appended, in order, to the contents of 453 * this sequence up to the (exclusive) index {@code end}. The length 454 * of this sequence is increased by the value of {@code end - start}. 455 * <p> 456 * Let <i>n</i> be the length of this character sequence just prior to 457 * execution of the {@code append} method. Then the character at 458 * index <i>k</i> in this character sequence becomes equal to the 459 * character at index <i>k</i> in this sequence, if <i>k</i> is less than 460 * <i>n</i>; otherwise, it is equal to the character at index 461 * <i>k+start-n</i> in the argument {@code s}. 462 * <p> 463 * If {@code s} is {@code null}, then this method appends 464 * characters as if the s parameter was a sequence containing the four 465 * characters {@code "null"}. 466 * 467 * @param s the sequence to append. 468 * @param start the starting index of the subsequence to be appended. 469 * @param end the end index of the subsequence to be appended. 470 * @return a reference to this object. 471 * @throws IndexOutOfBoundsException if 472 * {@code start} is negative, or 473 * {@code start} is greater than {@code end} or 474 * {@code end} is greater than {@code s.length()} 475 * @hide 476 */ append(CharSequence s, int start, int end)477 public AbstractStringBuilder append(CharSequence s, int start, int end) { 478 if (s == null) 479 s = "null"; 480 if ((start < 0) || (start > end) || (end > s.length())) 481 throw new IndexOutOfBoundsException( 482 "start " + start + ", end " + end + ", s.length() " 483 + s.length()); 484 int len = end - start; 485 ensureCapacityInternal(count + len); 486 if (s instanceof String) { 487 ((String) s).getCharsNoCheck(start, end, value, count); 488 } else if (s instanceof AbstractStringBuilder) { 489 AbstractStringBuilder other = (AbstractStringBuilder) s; 490 System.arraycopy(other.value, start, value, count, len); 491 } else { 492 for (int i = start, j = count; i < end; i++, j++) { 493 value[j] = s.charAt(i); 494 } 495 } 496 count += len; 497 return this; 498 } 499 500 /** 501 * Appends the string representation of the {@code char} array 502 * argument to this sequence. 503 * <p> 504 * The characters of the array argument are appended, in order, to 505 * the contents of this sequence. The length of this sequence 506 * increases by the length of the argument. 507 * <p> 508 * The overall effect is exactly as if the argument were converted 509 * to a string by the method {@link String#valueOf(char[])}, 510 * and the characters of that string were then 511 * {@link #append(String) appended} to this character sequence. 512 * 513 * @param str the characters to be appended. 514 * @return a reference to this object. 515 * @hide 516 */ append(char[] str)517 public AbstractStringBuilder append(char[] str) { 518 int len = str.length; 519 ensureCapacityInternal(count + len); 520 System.arraycopy(str, 0, value, count, len); 521 count += len; 522 return this; 523 } 524 525 /** 526 * Appends the string representation of a subarray of the 527 * {@code char} array argument to this sequence. 528 * <p> 529 * Characters of the {@code char} array {@code str}, starting at 530 * index {@code offset}, are appended, in order, to the contents 531 * of this sequence. The length of this sequence increases 532 * by the value of {@code len}. 533 * <p> 534 * The overall effect is exactly as if the arguments were converted 535 * to a string by the method {@link String#valueOf(char[],int,int)}, 536 * and the characters of that string were then 537 * {@link #append(String) appended} to this character sequence. 538 * 539 * @param str the characters to be appended. 540 * @param offset the index of the first {@code char} to append. 541 * @param len the number of {@code char}s to append. 542 * @return a reference to this object. 543 * @throws IndexOutOfBoundsException 544 * if {@code offset < 0} or {@code len < 0} 545 * or {@code offset+len > str.length} 546 * @hide 547 */ append(char str[], int offset, int len)548 public AbstractStringBuilder append(char str[], int offset, int len) { 549 if (len > 0) // let arraycopy report AIOOBE for len < 0 550 ensureCapacityInternal(count + len); 551 System.arraycopy(str, offset, value, count, len); 552 count += len; 553 return this; 554 } 555 556 /** 557 * Appends the string representation of the {@code boolean} 558 * argument to the sequence. 559 * <p> 560 * The overall effect is exactly as if the argument were converted 561 * to a string by the method {@link String#valueOf(boolean)}, 562 * and the characters of that string were then 563 * {@link #append(String) appended} to this character sequence. 564 * 565 * @param b a {@code boolean}. 566 * @return a reference to this object. 567 * @hide 568 */ append(boolean b)569 public AbstractStringBuilder append(boolean b) { 570 if (b) { 571 ensureCapacityInternal(count + 4); 572 value[count] = 't'; 573 value[count+1] = 'r'; 574 value[count+2] = 'u'; 575 value[count+3] = 'e'; 576 count += 4; 577 } else { 578 ensureCapacityInternal(count + 5); 579 value[count] = 'f'; 580 value[count+1] = 'a'; 581 value[count+2] = 'l'; 582 value[count+3] = 's'; 583 value[count+4] = 'e'; 584 count += 5; 585 } 586 return this; 587 } 588 589 /** 590 * Appends the string representation of the {@code char} 591 * argument to this sequence. 592 * <p> 593 * The argument is appended to the contents of this sequence. 594 * The length of this sequence increases by {@code 1}. 595 * <p> 596 * The overall effect is exactly as if the argument were converted 597 * to a string by the method {@link String#valueOf(char)}, 598 * and the character in that string were then 599 * {@link #append(String) appended} to this character sequence. 600 * 601 * @param c a {@code char}. 602 * @return a reference to this object. 603 * @hide 604 */ append(char c)605 public AbstractStringBuilder append(char c) { 606 ensureCapacityInternal(count + 1); 607 value[count++] = c; 608 return this; 609 } 610 611 /** 612 * Appends the string representation of the {@code int} 613 * argument to this sequence. 614 * <p> 615 * The overall effect is exactly as if the argument were converted 616 * to a string by the method {@link String#valueOf(int)}, 617 * and the characters of that string were then 618 * {@link #append(String) appended} to this character sequence. 619 * 620 * @param i an {@code int}. 621 * @return a reference to this object. 622 * @hide 623 */ append(int i)624 public AbstractStringBuilder append(int i) { 625 if (i == Integer.MIN_VALUE) { 626 append("-2147483648"); 627 return this; 628 } 629 int appendedLength = (i < 0) ? Integer.stringSize(-i) + 1 630 : Integer.stringSize(i); 631 int spaceNeeded = count + appendedLength; 632 ensureCapacityInternal(spaceNeeded); 633 Integer.getChars(i, spaceNeeded, value); 634 count = spaceNeeded; 635 return this; 636 } 637 638 /** 639 * Appends the string representation of the {@code long} 640 * argument to this sequence. 641 * <p> 642 * The overall effect is exactly as if the argument were converted 643 * to a string by the method {@link String#valueOf(long)}, 644 * and the characters of that string were then 645 * {@link #append(String) appended} to this character sequence. 646 * 647 * @param l a {@code long}. 648 * @return a reference to this object. 649 * @hide 650 */ append(long l)651 public AbstractStringBuilder append(long l) { 652 if (l == Long.MIN_VALUE) { 653 append("-9223372036854775808"); 654 return this; 655 } 656 int appendedLength = (l < 0) ? Long.stringSize(-l) + 1 657 : Long.stringSize(l); 658 int spaceNeeded = count + appendedLength; 659 ensureCapacityInternal(spaceNeeded); 660 Long.getChars(l, spaceNeeded, value); 661 count = spaceNeeded; 662 return this; 663 } 664 665 /** 666 * Appends the string representation of the {@code float} 667 * argument to this sequence. 668 * <p> 669 * The overall effect is exactly as if the argument were converted 670 * to a string by the method {@link String#valueOf(float)}, 671 * and the characters of that string were then 672 * {@link #append(String) appended} to this character sequence. 673 * 674 * @param f a {@code float}. 675 * @return a reference to this object. 676 * @hide 677 */ append(float f)678 public AbstractStringBuilder append(float f) { 679 FloatingDecimal.getThreadLocalInstance() 680 .loadFloat(f) 681 .appendTo(this); 682 return this; 683 } 684 685 /** 686 * Appends the string representation of the {@code double} 687 * argument to this sequence. 688 * <p> 689 * The overall effect is exactly as if the argument were converted 690 * to a string by the method {@link String#valueOf(double)}, 691 * and the characters of that string were then 692 * {@link #append(String) appended} to this character sequence. 693 * 694 * @param d a {@code double}. 695 * @return a reference to this object. 696 * @hide 697 */ append(double d)698 public AbstractStringBuilder append(double d) { 699 FloatingDecimal.getThreadLocalInstance() 700 .loadDouble(d) 701 .appendTo(this); 702 return this; 703 } 704 705 /** 706 * Removes the characters in a substring of this sequence. 707 * The substring begins at the specified {@code start} and extends to 708 * the character at index {@code end - 1} or to the end of the 709 * sequence if no such character exists. If 710 * {@code start} is equal to {@code end}, no changes are made. 711 * 712 * @param start The beginning index, inclusive. 713 * @param end The ending index, exclusive. 714 * @return This object. 715 * @throws StringIndexOutOfBoundsException if {@code start} 716 * is negative, greater than {@code length()}, or 717 * greater than {@code end}. 718 * @hide 719 */ delete(int start, int end)720 public AbstractStringBuilder delete(int start, int end) { 721 if (start < 0) 722 throw new StringIndexOutOfBoundsException(start); 723 if (end > count) 724 end = count; 725 if (start > end) 726 throw new StringIndexOutOfBoundsException(); 727 int len = end - start; 728 if (len > 0) { 729 System.arraycopy(value, start+len, value, start, count-end); 730 count -= len; 731 } 732 return this; 733 } 734 735 /** 736 * Appends the string representation of the {@code codePoint} 737 * argument to this sequence. 738 * 739 * <p> The argument is appended to the contents of this sequence. 740 * The length of this sequence increases by 741 * {@link Character#charCount(int) Character.charCount(codePoint)}. 742 * 743 * <p> The overall effect is exactly as if the argument were 744 * converted to a {@code char} array by the method 745 * {@link Character#toChars(int)} and the character in that array 746 * were then {@link #append(char[]) appended} to this character 747 * sequence. 748 * 749 * @param codePoint a Unicode code point 750 * @return a reference to this object. 751 * @exception IllegalArgumentException if the specified 752 * {@code codePoint} isn't a valid Unicode code point 753 * @hide 754 */ appendCodePoint(int codePoint)755 public AbstractStringBuilder appendCodePoint(int codePoint) { 756 final int count = this.count; 757 758 if (Character.isBmpCodePoint(codePoint)) { 759 ensureCapacityInternal(count + 1); 760 value[count] = (char) codePoint; 761 this.count = count + 1; 762 } else if (Character.isValidCodePoint(codePoint)) { 763 ensureCapacityInternal(count + 2); 764 Character.toSurrogates(codePoint, value, count); 765 this.count = count + 2; 766 } else { 767 throw new IllegalArgumentException(); 768 } 769 return this; 770 } 771 772 /** 773 * Removes the <code>char</code> at the specified position in this 774 * sequence. This sequence is shortened by one <code>char</code>. 775 * 776 * <p>Note: If the character at the given index is a supplementary 777 * character, this method does not remove the entire character. If 778 * correct handling of supplementary characters is required, 779 * determine the number of <code>char</code>s to remove by calling 780 * <code>Character.charCount(thisSequence.codePointAt(index))</code>, 781 * where <code>thisSequence</code> is this sequence. 782 * 783 * @param index Index of <code>char</code> to remove 784 * @return This object. 785 * @throws StringIndexOutOfBoundsException if the <code>index</code> 786 * is negative or greater than or equal to 787 * <code>length()</code>. 788 * @hide 789 */ deleteCharAt(int index)790 public AbstractStringBuilder deleteCharAt(int index) { 791 if ((index < 0) || (index >= count)) 792 throw new StringIndexOutOfBoundsException(index); 793 System.arraycopy(value, index+1, value, index, count-index-1); 794 count--; 795 return this; 796 } 797 798 /** 799 * Replaces the characters in a substring of this sequence 800 * with characters in the specified <code>String</code>. The substring 801 * begins at the specified <code>start</code> and extends to the character 802 * at index <code>end - 1</code> or to the end of the 803 * sequence if no such character exists. First the 804 * characters in the substring are removed and then the specified 805 * <code>String</code> is inserted at <code>start</code>. (This 806 * sequence will be lengthened to accommodate the 807 * specified String if necessary.) 808 * 809 * @param start The beginning index, inclusive. 810 * @param end The ending index, exclusive. 811 * @param str String that will replace previous contents. 812 * @return This object. 813 * @throws StringIndexOutOfBoundsException if <code>start</code> 814 * is negative, greater than <code>length()</code>, or 815 * greater than <code>end</code>. 816 * @hide 817 */ replace(int start, int end, String str)818 public AbstractStringBuilder replace(int start, int end, String str) { 819 if (start < 0) 820 throw new StringIndexOutOfBoundsException(start); 821 if (start > count) 822 throw new StringIndexOutOfBoundsException("start > length()"); 823 if (start > end) 824 throw new StringIndexOutOfBoundsException("start > end"); 825 826 if (end > count) 827 end = count; 828 int len = str.length(); 829 int newCount = count + len - (end - start); 830 ensureCapacityInternal(newCount); 831 832 System.arraycopy(value, end, value, start + len, count - end); 833 str.getCharsNoCheck(0, len, value, start); 834 count = newCount; 835 return this; 836 } 837 838 /** 839 * Returns a new <code>String</code> that contains a subsequence of 840 * characters currently contained in this character sequence. The 841 * substring begins at the specified index and extends to the end of 842 * this sequence. 843 * 844 * @param start The beginning index, inclusive. 845 * @return The new string. 846 * @throws StringIndexOutOfBoundsException if <code>start</code> is 847 * less than zero, or greater than the length of this object. 848 */ substring(int start)849 public String substring(int start) { 850 return substring(start, count); 851 } 852 853 /** 854 * Returns a new character sequence that is a subsequence of this sequence. 855 * 856 * <p> An invocation of this method of the form 857 * 858 * <blockquote><pre> 859 * sb.subSequence(begin, end)</pre></blockquote> 860 * 861 * behaves in exactly the same way as the invocation 862 * 863 * <blockquote><pre> 864 * sb.substring(begin, end)</pre></blockquote> 865 * 866 * This method is provided so that this class can 867 * implement the {@link CharSequence} interface. </p> 868 * 869 * @param start the start index, inclusive. 870 * @param end the end index, exclusive. 871 * @return the specified subsequence. 872 * 873 * @throws IndexOutOfBoundsException 874 * if <tt>start</tt> or <tt>end</tt> are negative, 875 * if <tt>end</tt> is greater than <tt>length()</tt>, 876 * or if <tt>start</tt> is greater than <tt>end</tt> 877 * @spec JSR-51 878 */ subSequence(int start, int end)879 public CharSequence subSequence(int start, int end) { 880 return substring(start, end); 881 } 882 883 /** 884 * Returns a new <code>String</code> that contains a subsequence of 885 * characters currently contained in this sequence. The 886 * substring begins at the specified <code>start</code> and 887 * extends to the character at index <code>end - 1</code>. 888 * 889 * @param start The beginning index, inclusive. 890 * @param end The ending index, exclusive. 891 * @return The new string. 892 * @throws StringIndexOutOfBoundsException if <code>start</code> 893 * or <code>end</code> are negative or greater than 894 * <code>length()</code>, or <code>start</code> is 895 * greater than <code>end</code>. 896 */ substring(int start, int end)897 public String substring(int start, int end) { 898 if (start < 0) 899 throw new StringIndexOutOfBoundsException(start); 900 if (end > count) 901 throw new StringIndexOutOfBoundsException(end); 902 if (start > end) 903 throw new StringIndexOutOfBoundsException(end - start); 904 return new String(value, start, end - start); 905 } 906 907 /** 908 * Inserts the string representation of a subarray of the {@code str} 909 * array argument into this sequence. The subarray begins at the 910 * specified {@code offset} and extends {@code len} {@code char}s. 911 * The characters of the subarray are inserted into this sequence at 912 * the position indicated by {@code index}. The length of this 913 * sequence increases by {@code len} {@code char}s. 914 * 915 * @param index position at which to insert subarray. 916 * @param str A {@code char} array. 917 * @param offset the index of the first {@code char} in subarray to 918 * be inserted. 919 * @param len the number of {@code char}s in the subarray to 920 * be inserted. 921 * @return This object 922 * @throws StringIndexOutOfBoundsException if {@code index} 923 * is negative or greater than {@code length()}, or 924 * {@code offset} or {@code len} are negative, or 925 * {@code (offset+len)} is greater than 926 * {@code str.length}. 927 * @hide 928 */ insert(int index, char[] str, int offset, int len)929 public AbstractStringBuilder insert(int index, char[] str, int offset, 930 int len) 931 { 932 if ((index < 0) || (index > length())) 933 throw new StringIndexOutOfBoundsException(index); 934 if ((offset < 0) || (len < 0) || (offset > str.length - len)) 935 throw new StringIndexOutOfBoundsException( 936 "offset " + offset + ", len " + len + ", str.length " 937 + str.length); 938 ensureCapacityInternal(count + len); 939 System.arraycopy(value, index, value, index + len, count - index); 940 System.arraycopy(str, offset, value, index, len); 941 count += len; 942 return this; 943 } 944 945 /** 946 * Inserts the string representation of the {@code Object} 947 * argument into this character sequence. 948 * <p> 949 * The overall effect is exactly as if the second argument were 950 * converted to a string by the method {@link String#valueOf(Object)}, 951 * and the characters of that string were then 952 * {@link #insert(int,String) inserted} into this character 953 * sequence at the indicated offset. 954 * <p> 955 * The {@code offset} argument must be greater than or equal to 956 * {@code 0}, and less than or equal to the {@linkplain #length() length} 957 * of this sequence. 958 * 959 * @param offset the offset. 960 * @param obj an {@code Object}. 961 * @return a reference to this object. 962 * @throws StringIndexOutOfBoundsException if the offset is invalid. 963 * @hide 964 */ insert(int offset, Object obj)965 public AbstractStringBuilder insert(int offset, Object obj) { 966 return insert(offset, String.valueOf(obj)); 967 } 968 969 /** 970 * Inserts the string into this character sequence. 971 * <p> 972 * The characters of the {@code String} argument are inserted, in 973 * order, into this sequence at the indicated offset, moving up any 974 * characters originally above that position and increasing the length 975 * of this sequence by the length of the argument. If 976 * {@code str} is {@code null}, then the four characters 977 * {@code "null"} are inserted into this sequence. 978 * <p> 979 * The character at index <i>k</i> in the new character sequence is 980 * equal to: 981 * <ul> 982 * <li>the character at index <i>k</i> in the old character sequence, if 983 * <i>k</i> is less than {@code offset} 984 * <li>the character at index <i>k</i>{@code -offset} in the 985 * argument {@code str}, if <i>k</i> is not less than 986 * {@code offset} but is less than {@code offset+str.length()} 987 * <li>the character at index <i>k</i>{@code -str.length()} in the 988 * old character sequence, if <i>k</i> is not less than 989 * {@code offset+str.length()} 990 * </ul><p> 991 * The {@code offset} argument must be greater than or equal to 992 * {@code 0}, and less than or equal to the {@linkplain #length() length} 993 * of this sequence. 994 * 995 * @param offset the offset. 996 * @param str a string. 997 * @return a reference to this object. 998 * @throws StringIndexOutOfBoundsException if the offset is invalid. 999 * @hide 1000 */ insert(int offset, String str)1001 public AbstractStringBuilder insert(int offset, String str) { 1002 if ((offset < 0) || (offset > length())) 1003 throw new StringIndexOutOfBoundsException(offset); 1004 if (str == null) 1005 str = "null"; 1006 int len = str.length(); 1007 ensureCapacityInternal(count + len); 1008 System.arraycopy(value, offset, value, offset + len, count - offset); 1009 str.getCharsNoCheck(0, len, value, offset); 1010 count += len; 1011 return this; 1012 } 1013 1014 /** 1015 * Inserts the string representation of the {@code char} array 1016 * argument into this sequence. 1017 * <p> 1018 * The characters of the array argument are inserted into the 1019 * contents of this sequence at the position indicated by 1020 * {@code offset}. The length of this sequence increases by 1021 * the length of the argument. 1022 * <p> 1023 * The overall effect is exactly as if the second argument were 1024 * converted to a string by the method {@link String#valueOf(char[])}, 1025 * and the characters of that string were then 1026 * {@link #insert(int,String) inserted} into this character 1027 * sequence at the indicated offset. 1028 * <p> 1029 * The {@code offset} argument must be greater than or equal to 1030 * {@code 0}, and less than or equal to the {@linkplain #length() length} 1031 * of this sequence. 1032 * 1033 * @param offset the offset. 1034 * @param str a character array. 1035 * @return a reference to this object. 1036 * @throws StringIndexOutOfBoundsException if the offset is invalid. 1037 * @hide 1038 */ insert(int offset, char[] str)1039 public AbstractStringBuilder insert(int offset, char[] str) { 1040 if ((offset < 0) || (offset > length())) 1041 throw new StringIndexOutOfBoundsException(offset); 1042 int len = str.length; 1043 ensureCapacityInternal(count + len); 1044 System.arraycopy(value, offset, value, offset + len, count - offset); 1045 System.arraycopy(str, 0, value, offset, len); 1046 count += len; 1047 return this; 1048 } 1049 1050 /** 1051 * Inserts the specified {@code CharSequence} into this sequence. 1052 * <p> 1053 * The characters of the {@code CharSequence} argument are inserted, 1054 * in order, into this sequence at the indicated offset, moving up 1055 * any characters originally above that position and increasing the length 1056 * of this sequence by the length of the argument s. 1057 * <p> 1058 * The result of this method is exactly the same as if it were an 1059 * invocation of this object's 1060 * {@link #insert(int,CharSequence,int,int) insert}(dstOffset, s, 0, s.length()) 1061 * method. 1062 * 1063 * <p>If {@code s} is {@code null}, then the four characters 1064 * {@code "null"} are inserted into this sequence. 1065 * 1066 * @param dstOffset the offset. 1067 * @param s the sequence to be inserted 1068 * @return a reference to this object. 1069 * @throws IndexOutOfBoundsException if the offset is invalid. 1070 * @hide 1071 */ insert(int dstOffset, CharSequence s)1072 public AbstractStringBuilder insert(int dstOffset, CharSequence s) { 1073 if (s == null) 1074 s = "null"; 1075 if (s instanceof String) 1076 return this.insert(dstOffset, (String)s); 1077 return this.insert(dstOffset, s, 0, s.length()); 1078 } 1079 1080 /** 1081 * Inserts a subsequence of the specified {@code CharSequence} into 1082 * this sequence. 1083 * <p> 1084 * The subsequence of the argument {@code s} specified by 1085 * {@code start} and {@code end} are inserted, 1086 * in order, into this sequence at the specified destination offset, moving 1087 * up any characters originally above that position. The length of this 1088 * sequence is increased by {@code end - start}. 1089 * <p> 1090 * The character at index <i>k</i> in this sequence becomes equal to: 1091 * <ul> 1092 * <li>the character at index <i>k</i> in this sequence, if 1093 * <i>k</i> is less than {@code dstOffset} 1094 * <li>the character at index <i>k</i>{@code +start-dstOffset} in 1095 * the argument {@code s}, if <i>k</i> is greater than or equal to 1096 * {@code dstOffset} but is less than {@code dstOffset+end-start} 1097 * <li>the character at index <i>k</i>{@code -(end-start)} in this 1098 * sequence, if <i>k</i> is greater than or equal to 1099 * {@code dstOffset+end-start} 1100 * </ul><p> 1101 * The {@code dstOffset} argument must be greater than or equal to 1102 * {@code 0}, and less than or equal to the {@linkplain #length() length} 1103 * of this sequence. 1104 * <p>The start argument must be nonnegative, and not greater than 1105 * {@code end}. 1106 * <p>The end argument must be greater than or equal to 1107 * {@code start}, and less than or equal to the length of s. 1108 * 1109 * <p>If {@code s} is {@code null}, then this method inserts 1110 * characters as if the s parameter was a sequence containing the four 1111 * characters {@code "null"}. 1112 * 1113 * @param dstOffset the offset in this sequence. 1114 * @param s the sequence to be inserted. 1115 * @param start the starting index of the subsequence to be inserted. 1116 * @param end the end index of the subsequence to be inserted. 1117 * @return a reference to this object. 1118 * @throws IndexOutOfBoundsException if {@code dstOffset} 1119 * is negative or greater than {@code this.length()}, or 1120 * {@code start} or {@code end} are negative, or 1121 * {@code start} is greater than {@code end} or 1122 * {@code end} is greater than {@code s.length()} 1123 * @hide 1124 */ insert(int dstOffset, CharSequence s, int start, int end)1125 public AbstractStringBuilder insert(int dstOffset, CharSequence s, 1126 int start, int end) { 1127 if (s == null) 1128 s = "null"; 1129 if ((dstOffset < 0) || (dstOffset > this.length())) 1130 throw new IndexOutOfBoundsException("dstOffset "+dstOffset); 1131 if ((start < 0) || (end < 0) || (start > end) || (end > s.length())) 1132 throw new IndexOutOfBoundsException( 1133 "start " + start + ", end " + end + ", s.length() " 1134 + s.length()); 1135 int len = end - start; 1136 ensureCapacityInternal(count + len); 1137 System.arraycopy(value, dstOffset, value, dstOffset + len, 1138 count - dstOffset); 1139 for (int i=start; i<end; i++) 1140 value[dstOffset++] = s.charAt(i); 1141 count += len; 1142 return this; 1143 } 1144 1145 /** 1146 * Inserts the string representation of the {@code boolean} 1147 * argument into this sequence. 1148 * <p> 1149 * The overall effect is exactly as if the second argument were 1150 * converted to a string by the method {@link String#valueOf(boolean)}, 1151 * and the characters of that string were then 1152 * {@link #insert(int,String) inserted} into this character 1153 * sequence at the indicated offset. 1154 * <p> 1155 * The {@code offset} argument must be greater than or equal to 1156 * {@code 0}, and less than or equal to the {@linkplain #length() length} 1157 * of this sequence. 1158 * 1159 * @param offset the offset. 1160 * @param b a {@code boolean}. 1161 * @return a reference to this object. 1162 * @throws StringIndexOutOfBoundsException if the offset is invalid. 1163 * @hide 1164 */ insert(int offset, boolean b)1165 public AbstractStringBuilder insert(int offset, boolean b) { 1166 return insert(offset, String.valueOf(b)); 1167 } 1168 1169 /** 1170 * Inserts the string representation of the {@code char} 1171 * argument into this sequence. 1172 * <p> 1173 * The overall effect is exactly as if the second argument were 1174 * converted to a string by the method {@link String#valueOf(char)}, 1175 * and the character in that string were then 1176 * {@link #insert(int,String) inserted} into this character 1177 * sequence at the indicated offset. 1178 * <p> 1179 * The {@code offset} argument must be greater than or equal to 1180 * {@code 0}, and less than or equal to the {@linkplain #length() length} 1181 * of this sequence. 1182 * 1183 * @param offset the offset. 1184 * @param c a {@code char}. 1185 * @return a reference to this object. 1186 * @throws IndexOutOfBoundsException if the offset is invalid. 1187 * @hide 1188 */ insert(int offset, char c)1189 public AbstractStringBuilder insert(int offset, char c) { 1190 ensureCapacityInternal(count + 1); 1191 System.arraycopy(value, offset, value, offset + 1, count - offset); 1192 value[offset] = c; 1193 count += 1; 1194 return this; 1195 } 1196 1197 /** 1198 * Inserts the string representation of the second {@code int} 1199 * argument into this sequence. 1200 * <p> 1201 * The overall effect is exactly as if the second argument were 1202 * converted to a string by the method {@link String#valueOf(int)}, 1203 * and the characters of that string were then 1204 * {@link #insert(int,String) inserted} into this character 1205 * sequence at the indicated offset. 1206 * <p> 1207 * The {@code offset} argument must be greater than or equal to 1208 * {@code 0}, and less than or equal to the {@linkplain #length() length} 1209 * of this sequence. 1210 * 1211 * @param offset the offset. 1212 * @param i an {@code int}. 1213 * @return a reference to this object. 1214 * @throws StringIndexOutOfBoundsException if the offset is invalid. 1215 * @hide 1216 */ insert(int offset, int i)1217 public AbstractStringBuilder insert(int offset, int i) { 1218 return insert(offset, String.valueOf(i)); 1219 } 1220 1221 /** 1222 * Inserts the string representation of the {@code long} 1223 * argument into this sequence. 1224 * <p> 1225 * The overall effect is exactly as if the second argument were 1226 * converted to a string by the method {@link String#valueOf(long)}, 1227 * and the characters of that string were then 1228 * {@link #insert(int,String) inserted} into this character 1229 * sequence at the indicated offset. 1230 * <p> 1231 * The {@code offset} argument must be greater than or equal to 1232 * {@code 0}, and less than or equal to the {@linkplain #length() length} 1233 * of this sequence. 1234 * 1235 * @param offset the offset. 1236 * @param l a {@code long}. 1237 * @return a reference to this object. 1238 * @throws StringIndexOutOfBoundsException if the offset is invalid. 1239 * @hide 1240 */ insert(int offset, long l)1241 public AbstractStringBuilder insert(int offset, long l) { 1242 return insert(offset, String.valueOf(l)); 1243 } 1244 1245 /** 1246 * Inserts the string representation of the {@code float} 1247 * argument into this sequence. 1248 * <p> 1249 * The overall effect is exactly as if the second argument were 1250 * converted to a string by the method {@link String#valueOf(float)}, 1251 * and the characters of that string were then 1252 * {@link #insert(int,String) inserted} into this character 1253 * sequence at the indicated offset. 1254 * <p> 1255 * The {@code offset} argument must be greater than or equal to 1256 * {@code 0}, and less than or equal to the {@linkplain #length() length} 1257 * of this sequence. 1258 * 1259 * @param offset the offset. 1260 * @param f a {@code float}. 1261 * @return a reference to this object. 1262 * @throws StringIndexOutOfBoundsException if the offset is invalid. 1263 * @hide 1264 */ insert(int offset, float f)1265 public AbstractStringBuilder insert(int offset, float f) { 1266 return insert(offset, String.valueOf(f)); 1267 } 1268 1269 /** 1270 * Inserts the string representation of the {@code double} 1271 * argument into this sequence. 1272 * <p> 1273 * The overall effect is exactly as if the second argument were 1274 * converted to a string by the method {@link String#valueOf(double)}, 1275 * and the characters of that string were then 1276 * {@link #insert(int,String) inserted} into this character 1277 * sequence at the indicated offset. 1278 * <p> 1279 * The {@code offset} argument must be greater than or equal to 1280 * {@code 0}, and less than or equal to the {@linkplain #length() length} 1281 * of this sequence. 1282 * 1283 * @param offset the offset. 1284 * @param d a {@code double}. 1285 * @return a reference to this object. 1286 * @throws StringIndexOutOfBoundsException if the offset is invalid. 1287 * @hide 1288 */ insert(int offset, double d)1289 public AbstractStringBuilder insert(int offset, double d) { 1290 return insert(offset, String.valueOf(d)); 1291 } 1292 1293 /** 1294 * Returns the index within this string of the first occurrence of the 1295 * specified substring. The integer returned is the smallest value 1296 * <i>k</i> such that: 1297 * <blockquote><pre> 1298 * this.toString().startsWith(str, <i>k</i>) 1299 * </pre></blockquote> 1300 * is <code>true</code>. 1301 * 1302 * @param str any string. 1303 * @return if the string argument occurs as a substring within this 1304 * object, then the index of the first character of the first 1305 * such substring is returned; if it does not occur as a 1306 * substring, <code>-1</code> is returned. 1307 * @throws java.lang.NullPointerException if <code>str</code> is 1308 * <code>null</code>. 1309 */ indexOf(String str)1310 public int indexOf(String str) { 1311 return indexOf(str, 0); 1312 } 1313 1314 /** 1315 * Returns the index within this string of the first occurrence of the 1316 * specified substring, starting at the specified index. The integer 1317 * returned is the smallest value <tt>k</tt> for which: 1318 * <blockquote><pre> 1319 * k >= Math.min(fromIndex, str.length()) && 1320 * this.toString().startsWith(str, k) 1321 * </pre></blockquote> 1322 * If no such value of <i>k</i> exists, then -1 is returned. 1323 * 1324 * @param str the substring for which to search. 1325 * @param fromIndex the index from which to start the search. 1326 * @return the index within this string of the first occurrence of the 1327 * specified substring, starting at the specified index. 1328 * @throws java.lang.NullPointerException if <code>str</code> is 1329 * <code>null</code>. 1330 */ indexOf(String str, int fromIndex)1331 public int indexOf(String str, int fromIndex) { 1332 return String.indexOf(value, 0, count, 1333 str.toCharArray(), 0, str.length(), fromIndex); 1334 } 1335 1336 /** 1337 * Returns the index within this string of the rightmost occurrence 1338 * of the specified substring. The rightmost empty string "" is 1339 * considered to occur at the index value <code>this.length()</code>. 1340 * The returned index is the largest value <i>k</i> such that 1341 * <blockquote><pre> 1342 * this.toString().startsWith(str, k) 1343 * </pre></blockquote> 1344 * is true. 1345 * 1346 * @param str the substring to search for. 1347 * @return if the string argument occurs one or more times as a substring 1348 * within this object, then the index of the first character of 1349 * the last such substring is returned. If it does not occur as 1350 * a substring, <code>-1</code> is returned. 1351 * @throws java.lang.NullPointerException if <code>str</code> is 1352 * <code>null</code>. 1353 */ lastIndexOf(String str)1354 public int lastIndexOf(String str) { 1355 return lastIndexOf(str, count); 1356 } 1357 1358 /** 1359 * Returns the index within this string of the last occurrence of the 1360 * specified substring. The integer returned is the largest value <i>k</i> 1361 * such that: 1362 * <blockquote><pre> 1363 * k <= Math.min(fromIndex, str.length()) && 1364 * this.toString().startsWith(str, k) 1365 * </pre></blockquote> 1366 * If no such value of <i>k</i> exists, then -1 is returned. 1367 * 1368 * @param str the substring to search for. 1369 * @param fromIndex the index to start the search from. 1370 * @return the index within this sequence of the last occurrence of the 1371 * specified substring. 1372 * @throws java.lang.NullPointerException if <code>str</code> is 1373 * <code>null</code>. 1374 */ lastIndexOf(String str, int fromIndex)1375 public int lastIndexOf(String str, int fromIndex) { 1376 return String.lastIndexOf(value, 0, count, 1377 str.toCharArray(), 0, str.length(), fromIndex); 1378 } 1379 1380 /** 1381 * Causes this character sequence to be replaced by the reverse of 1382 * the sequence. If there are any surrogate pairs included in the 1383 * sequence, these are treated as single characters for the 1384 * reverse operation. Thus, the order of the high-low surrogates 1385 * is never reversed. 1386 * 1387 * Let <i>n</i> be the character length of this character sequence 1388 * (not the length in <code>char</code> values) just prior to 1389 * execution of the <code>reverse</code> method. Then the 1390 * character at index <i>k</i> in the new character sequence is 1391 * equal to the character at index <i>n-k-1</i> in the old 1392 * character sequence. 1393 * 1394 * <p>Note that the reverse operation may result in producing 1395 * surrogate pairs that were unpaired low-surrogates and 1396 * high-surrogates before the operation. For example, reversing 1397 * "\uDC00\uD800" produces "\uD800\uDC00" which is 1398 * a valid surrogate pair. 1399 * 1400 * @return a reference to this object. 1401 * @hide 1402 */ reverse()1403 public AbstractStringBuilder reverse() { 1404 boolean hasSurrogate = false; 1405 int n = count - 1; 1406 for (int j = (n-1) >> 1; j >= 0; --j) { 1407 char temp = value[j]; 1408 char temp2 = value[n - j]; 1409 if (!hasSurrogate) { 1410 hasSurrogate = (temp >= Character.MIN_SURROGATE && temp <= Character.MAX_SURROGATE) 1411 || (temp2 >= Character.MIN_SURROGATE && temp2 <= Character.MAX_SURROGATE); 1412 } 1413 value[j] = temp2; 1414 value[n - j] = temp; 1415 } 1416 if (hasSurrogate) { 1417 // Reverse back all valid surrogate pairs 1418 for (int i = 0; i < count - 1; i++) { 1419 char c2 = value[i]; 1420 if (Character.isLowSurrogate(c2)) { 1421 char c1 = value[i + 1]; 1422 if (Character.isHighSurrogate(c1)) { 1423 value[i++] = c1; 1424 value[i] = c2; 1425 } 1426 } 1427 } 1428 } 1429 return this; 1430 } 1431 1432 /** 1433 * Returns a string representing the data in this sequence. 1434 * A new <code>String</code> object is allocated and initialized to 1435 * contain the character sequence currently represented by this 1436 * object. This <code>String</code> is then returned. Subsequent 1437 * changes to this sequence do not affect the contents of the 1438 * <code>String</code>. 1439 * 1440 * @return a string representation of this sequence of characters. 1441 * @hide 1442 */ toString()1443 public abstract String toString(); 1444 1445 /** 1446 * Needed by <tt>String</tt> for the contentEquals method. 1447 */ getValue()1448 final char[] getValue() { 1449 return value; 1450 } 1451 1452 } 1453