1/* 2 * Copyright (c) 2003, 2017, Oracle and/or its affiliates. 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. Oracle designates this 8 * particular file as subject to the "Classpath" exception as provided 9 * by Oracle 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 Oracle, 500 Oracle Parkway, Redwood Shores, CA 94065 USA 22 * or visit www.oracle.com if you need additional information or have any 23 * questions. 24 */ 25 26package java.lang; 27 28import jdk.internal.math.FloatingDecimal; 29import java.util.Arrays; 30import java.util.Spliterator; 31import java.util.stream.IntStream; 32import java.util.stream.StreamSupport; 33 34import static java.lang.String.COMPACT_STRINGS; 35import static java.lang.String.UTF16; 36import static java.lang.String.LATIN1; 37import static java.lang.String.checkIndex; 38import static java.lang.String.checkOffset; 39 40/** 41 * A mutable sequence of characters. 42 * <p> 43 * Implements a modifiable string. At any point in time it contains some 44 * particular sequence of characters, but the length and content of the 45 * sequence can be changed through certain method calls. 46 * 47 * <p>Unless otherwise noted, passing a {@code null} argument to a constructor 48 * or method in this class will cause a {@link NullPointerException} to be 49 * thrown. 50 * 51 * @author Michael McCloskey 52 * @author Martin Buchholz 53 * @author Ulf Zibis 54 * @since 1.5 55 */ 56abstract class AbstractStringBuilder implements Appendable, CharSequence { 57 /** 58 * The value is used for character storage. 59 */ 60 byte[] value; 61 62 /** 63 * The id of the encoding used to encode the bytes in {@code value}. 64 */ 65 byte coder; 66 67 /** 68 * The count is the number of characters used. 69 */ 70 int count; 71 72 /** 73 * This no-arg constructor is necessary for serialization of subclasses. 74 */ 75 AbstractStringBuilder() { 76 } 77 78 /** 79 * Creates an AbstractStringBuilder of the specified capacity. 80 */ 81 AbstractStringBuilder(int capacity) { 82 if (COMPACT_STRINGS) { 83 value = new byte[capacity]; 84 coder = LATIN1; 85 } else { 86 value = StringUTF16.newBytesFor(capacity); 87 coder = UTF16; 88 } 89 } 90 91 /** 92 * Returns the length (character count). 93 * 94 * @return the length of the sequence of characters currently 95 * represented by this object 96 */ 97 @Override 98 public int length() { 99 return count; 100 } 101 102 /** 103 * Returns the current capacity. The capacity is the amount of storage 104 * available for newly inserted characters, beyond which an allocation 105 * will occur. 106 * 107 * @return the current capacity 108 */ 109 public int capacity() { 110 return value.length >> coder; 111 } 112 113 /** 114 * Ensures that the capacity is at least equal to the specified minimum. 115 * If the current capacity is less than the argument, then a new internal 116 * array is allocated with greater capacity. The new capacity is the 117 * larger of: 118 * <ul> 119 * <li>The {@code minimumCapacity} argument. 120 * <li>Twice the old capacity, plus {@code 2}. 121 * </ul> 122 * If the {@code minimumCapacity} argument is nonpositive, this 123 * method takes no action and simply returns. 124 * Note that subsequent operations on this object can reduce the 125 * actual capacity below that requested here. 126 * 127 * @param minimumCapacity the minimum desired capacity. 128 */ 129 public void ensureCapacity(int minimumCapacity) { 130 if (minimumCapacity > 0) { 131 ensureCapacityInternal(minimumCapacity); 132 } 133 } 134 135 /** 136 * For positive values of {@code minimumCapacity}, this method 137 * behaves like {@code ensureCapacity}, however it is never 138 * synchronized. 139 * If {@code minimumCapacity} is non positive due to numeric 140 * overflow, this method throws {@code OutOfMemoryError}. 141 */ 142 private void ensureCapacityInternal(int minimumCapacity) { 143 // overflow-conscious code 144 int oldCapacity = value.length >> coder; 145 if (minimumCapacity - oldCapacity > 0) { 146 value = Arrays.copyOf(value, 147 newCapacity(minimumCapacity) << coder); 148 } 149 } 150 151 /** 152 * The maximum size of array to allocate (unless necessary). 153 * Some VMs reserve some header words in an array. 154 * Attempts to allocate larger arrays may result in 155 * OutOfMemoryError: Requested array size exceeds VM limit 156 */ 157 private static final int MAX_ARRAY_SIZE = Integer.MAX_VALUE - 8; 158 159 /** 160 * Returns a capacity at least as large as the given minimum capacity. 161 * Returns the current capacity increased by the same amount + 2 if 162 * that suffices. 163 * Will not return a capacity greater than 164 * {@code (MAX_ARRAY_SIZE >> coder)} unless the given minimum capacity 165 * is greater than that. 166 * 167 * @param minCapacity the desired minimum capacity 168 * @throws OutOfMemoryError if minCapacity is less than zero or 169 * greater than (Integer.MAX_VALUE >> coder) 170 */ 171 private int newCapacity(int minCapacity) { 172 // overflow-conscious code 173 int oldCapacity = value.length >> coder; 174 int newCapacity = (oldCapacity << 1) + 2; 175 if (newCapacity - minCapacity < 0) { 176 newCapacity = minCapacity; 177 } 178 int SAFE_BOUND = MAX_ARRAY_SIZE >> coder; 179 return (newCapacity <= 0 || SAFE_BOUND - newCapacity < 0) 180 ? hugeCapacity(minCapacity) 181 : newCapacity; 182 } 183 184 private int hugeCapacity(int minCapacity) { 185 int SAFE_BOUND = MAX_ARRAY_SIZE >> coder; 186 int UNSAFE_BOUND = Integer.MAX_VALUE >> coder; 187 if (UNSAFE_BOUND - minCapacity < 0) { // overflow 188 throw new OutOfMemoryError(); 189 } 190 return (minCapacity > SAFE_BOUND) 191 ? minCapacity : SAFE_BOUND; 192 } 193 194 /** 195 * If the coder is "isLatin1", this inflates the internal 8-bit storage 196 * to 16-bit <hi=0, low> pair storage. 197 */ 198 private void inflate() { 199 if (!isLatin1()) { 200 return; 201 } 202 byte[] buf = StringUTF16.newBytesFor(value.length); 203 StringLatin1.inflate(value, 0, buf, 0, count); 204 this.value = buf; 205 this.coder = UTF16; 206 } 207 208 /** 209 * Attempts to reduce storage used for the character sequence. 210 * If the buffer is larger than necessary to hold its current sequence of 211 * characters, then it may be resized to become more space efficient. 212 * Calling this method may, but is not required to, affect the value 213 * returned by a subsequent call to the {@link #capacity()} method. 214 */ 215 public void trimToSize() { 216 int length = count << coder; 217 if (length < value.length) { 218 value = Arrays.copyOf(value, length); 219 } 220 } 221 222 /** 223 * Sets the length of the character sequence. 224 * The sequence is changed to a new character sequence 225 * whose length is specified by the argument. For every nonnegative 226 * index <i>k</i> less than {@code newLength}, the character at 227 * index <i>k</i> in the new character sequence is the same as the 228 * character at index <i>k</i> in the old sequence if <i>k</i> is less 229 * than the length of the old character sequence; otherwise, it is the 230 * null character {@code '\u005Cu0000'}. 231 * 232 * In other words, if the {@code newLength} argument is less than 233 * the current length, the length is changed to the specified length. 234 * <p> 235 * If the {@code newLength} argument is greater than or equal 236 * to the current length, sufficient null characters 237 * ({@code '\u005Cu0000'}) are appended so that 238 * length becomes the {@code newLength} argument. 239 * <p> 240 * The {@code newLength} argument must be greater than or equal 241 * to {@code 0}. 242 * 243 * @param newLength the new length 244 * @throws IndexOutOfBoundsException if the 245 * {@code newLength} argument is negative. 246 */ 247 public void setLength(int newLength) { 248 if (newLength < 0) { 249 throw new StringIndexOutOfBoundsException(newLength); 250 } 251 ensureCapacityInternal(newLength); 252 if (count < newLength) { 253 if (isLatin1()) { 254 StringLatin1.fillNull(value, count, newLength); 255 } else { 256 StringUTF16.fillNull(value, count, newLength); 257 } 258 } 259 count = newLength; 260 } 261 262 /** 263 * Returns the {@code char} value in this sequence at the specified index. 264 * The first {@code char} value is at index {@code 0}, the next at index 265 * {@code 1}, and so on, as in array indexing. 266 * <p> 267 * The index argument must be greater than or equal to 268 * {@code 0}, and less than the length of this sequence. 269 * 270 * <p>If the {@code char} value specified by the index is a 271 * <a href="Character.html#unicode">surrogate</a>, the surrogate 272 * value is returned. 273 * 274 * @param index the index of the desired {@code char} value. 275 * @return the {@code char} value at the specified index. 276 * @throws IndexOutOfBoundsException if {@code index} is 277 * negative or greater than or equal to {@code length()}. 278 */ 279 @Override 280 public char charAt(int index) { 281 checkIndex(index, count); 282 if (isLatin1()) { 283 return (char)(value[index] & 0xff); 284 } 285 return StringUTF16.charAt(value, index); 286 } 287 288 /** 289 * Returns the character (Unicode code point) at the specified 290 * index. The index refers to {@code char} values 291 * (Unicode code units) and ranges from {@code 0} to 292 * {@link #length()}{@code - 1}. 293 * 294 * <p> If the {@code char} value specified at the given index 295 * is in the high-surrogate range, the following index is less 296 * than the length of this sequence, and the 297 * {@code char} value at the following index is in the 298 * low-surrogate range, then the supplementary code point 299 * corresponding to this surrogate pair is returned. Otherwise, 300 * the {@code char} value at the given index is returned. 301 * 302 * @param index the index to the {@code char} values 303 * @return the code point value of the character at the 304 * {@code index} 305 * @exception IndexOutOfBoundsException if the {@code index} 306 * argument is negative or not less than the length of this 307 * sequence. 308 */ 309 public int codePointAt(int index) { 310 int count = this.count; 311 byte[] value = this.value; 312 checkIndex(index, count); 313 if (isLatin1()) { 314 return value[index] & 0xff; 315 } 316 return StringUTF16.codePointAtSB(value, index, count); 317 } 318 319 /** 320 * Returns the character (Unicode code point) before the specified 321 * index. The index refers to {@code char} values 322 * (Unicode code units) and ranges from {@code 1} to {@link 323 * #length()}. 324 * 325 * <p> If the {@code char} value at {@code (index - 1)} 326 * is in the low-surrogate range, {@code (index - 2)} is not 327 * negative, and the {@code char} value at {@code (index - 328 * 2)} is in the high-surrogate range, then the 329 * supplementary code point value of the surrogate pair is 330 * returned. If the {@code char} value at {@code index - 331 * 1} is an unpaired low-surrogate or a high-surrogate, the 332 * surrogate value is returned. 333 * 334 * @param index the index following the code point that should be returned 335 * @return the Unicode code point value before the given index. 336 * @exception IndexOutOfBoundsException if the {@code index} 337 * argument is less than 1 or greater than the length 338 * of this sequence. 339 */ 340 public int codePointBefore(int index) { 341 int i = index - 1; 342 if (i < 0 || i >= count) { 343 throw new StringIndexOutOfBoundsException(index); 344 } 345 if (isLatin1()) { 346 return value[i] & 0xff; 347 } 348 return StringUTF16.codePointBeforeSB(value, index); 349 } 350 351 /** 352 * Returns the number of Unicode code points in the specified text 353 * range of this sequence. The text range begins at the specified 354 * {@code beginIndex} and extends to the {@code char} at 355 * index {@code endIndex - 1}. Thus the length (in 356 * {@code char}s) of the text range is 357 * {@code endIndex-beginIndex}. Unpaired surrogates within 358 * this sequence count as one code point each. 359 * 360 * @param beginIndex the index to the first {@code char} of 361 * the text range. 362 * @param endIndex the index after the last {@code char} of 363 * the text range. 364 * @return the number of Unicode code points in the specified text 365 * range 366 * @exception IndexOutOfBoundsException if the 367 * {@code beginIndex} is negative, or {@code endIndex} 368 * is larger than the length of this sequence, or 369 * {@code beginIndex} is larger than {@code endIndex}. 370 */ 371 public int codePointCount(int beginIndex, int endIndex) { 372 if (beginIndex < 0 || endIndex > count || beginIndex > endIndex) { 373 throw new IndexOutOfBoundsException(); 374 } 375 if (isLatin1()) { 376 return endIndex - beginIndex; 377 } 378 return StringUTF16.codePointCountSB(value, beginIndex, endIndex); 379 } 380 381 /** 382 * Returns the index within this sequence that is offset from the 383 * given {@code index} by {@code codePointOffset} code 384 * points. Unpaired surrogates within the text range given by 385 * {@code index} and {@code codePointOffset} count as 386 * one code point each. 387 * 388 * @param index the index to be offset 389 * @param codePointOffset the offset in code points 390 * @return the index within this sequence 391 * @exception IndexOutOfBoundsException if {@code index} 392 * is negative or larger then the length of this sequence, 393 * or if {@code codePointOffset} is positive and the subsequence 394 * starting with {@code index} has fewer than 395 * {@code codePointOffset} code points, 396 * or if {@code codePointOffset} is negative and the subsequence 397 * before {@code index} has fewer than the absolute value of 398 * {@code codePointOffset} code points. 399 */ 400 public int offsetByCodePoints(int index, int codePointOffset) { 401 if (index < 0 || index > count) { 402 throw new IndexOutOfBoundsException(); 403 } 404 return Character.offsetByCodePoints(this, 405 index, codePointOffset); 406 } 407 408 /** 409 * Characters are copied from this sequence into the 410 * destination character array {@code dst}. The first character to 411 * be copied is at index {@code srcBegin}; the last character to 412 * be copied is at index {@code srcEnd-1}. The total number of 413 * characters to be copied is {@code srcEnd-srcBegin}. The 414 * characters are copied into the subarray of {@code dst} starting 415 * at index {@code dstBegin} and ending at index: 416 * <pre>{@code 417 * dstbegin + (srcEnd-srcBegin) - 1 418 * }</pre> 419 * 420 * @param srcBegin start copying at this offset. 421 * @param srcEnd stop copying at this offset. 422 * @param dst the array to copy the data into. 423 * @param dstBegin offset into {@code dst}. 424 * @throws IndexOutOfBoundsException if any of the following is true: 425 * <ul> 426 * <li>{@code srcBegin} is negative 427 * <li>{@code dstBegin} is negative 428 * <li>the {@code srcBegin} argument is greater than 429 * the {@code srcEnd} argument. 430 * <li>{@code srcEnd} is greater than 431 * {@code this.length()}. 432 * <li>{@code dstBegin+srcEnd-srcBegin} is greater than 433 * {@code dst.length} 434 * </ul> 435 */ 436 public void getChars(int srcBegin, int srcEnd, char[] dst, int dstBegin) 437 { 438 checkRangeSIOOBE(srcBegin, srcEnd, count); // compatible to old version 439 int n = srcEnd - srcBegin; 440 checkRange(dstBegin, dstBegin + n, dst.length); 441 if (isLatin1()) { 442 StringLatin1.getChars(value, srcBegin, srcEnd, dst, dstBegin); 443 } else { 444 StringUTF16.getChars(value, srcBegin, srcEnd, dst, dstBegin); 445 } 446 } 447 448 /** 449 * The character at the specified index is set to {@code ch}. This 450 * sequence is altered to represent a new character sequence that is 451 * identical to the old character sequence, except that it contains the 452 * character {@code ch} at position {@code index}. 453 * <p> 454 * The index argument must be greater than or equal to 455 * {@code 0}, and less than the length of this sequence. 456 * 457 * @param index the index of the character to modify. 458 * @param ch the new character. 459 * @throws IndexOutOfBoundsException if {@code index} is 460 * negative or greater than or equal to {@code length()}. 461 */ 462 public void setCharAt(int index, char ch) { 463 checkIndex(index, count); 464 if (isLatin1() && StringLatin1.canEncode(ch)) { 465 value[index] = (byte)ch; 466 } else { 467 if (isLatin1()) { 468 inflate(); 469 } 470 StringUTF16.putCharSB(value, index, ch); 471 } 472 } 473 474 /** 475 * Appends the string representation of the {@code Object} argument. 476 * <p> 477 * The overall effect is exactly as if the argument were converted 478 * to a string by the method {@link String#valueOf(Object)}, 479 * and the characters of that string were then 480 * {@link #append(String) appended} to this character sequence. 481 * 482 * @param obj an {@code Object}. 483 * @return a reference to this object. 484 */ 485 public AbstractStringBuilder append(Object obj) { 486 return append(String.valueOf(obj)); 487 } 488 489 /** 490 * Appends the specified string to this character sequence. 491 * <p> 492 * The characters of the {@code String} argument are appended, in 493 * order, increasing the length of this sequence by the length of the 494 * argument. If {@code str} is {@code null}, then the four 495 * characters {@code "null"} are appended. 496 * <p> 497 * Let <i>n</i> be the length of this character sequence just prior to 498 * execution of the {@code append} method. Then the character at 499 * index <i>k</i> in the new character sequence is equal to the character 500 * at index <i>k</i> in the old character sequence, if <i>k</i> is less 501 * than <i>n</i>; otherwise, it is equal to the character at index 502 * <i>k-n</i> in the argument {@code str}. 503 * 504 * @param str a string. 505 * @return a reference to this object. 506 */ 507 public AbstractStringBuilder append(String str) { 508 if (str == null) { 509 return appendNull(); 510 } 511 int len = str.length(); 512 ensureCapacityInternal(count + len); 513 putStringAt(count, str); 514 count += len; 515 return this; 516 } 517 518 // Documentation in subclasses because of synchro difference 519 public AbstractStringBuilder append(StringBuffer sb) { 520 return this.append((AbstractStringBuilder)sb); 521 } 522 523 /** 524 * @since 1.8 525 */ 526 AbstractStringBuilder append(AbstractStringBuilder asb) { 527 if (asb == null) { 528 return appendNull(); 529 } 530 int len = asb.length(); 531 ensureCapacityInternal(count + len); 532 if (getCoder() != asb.getCoder()) { 533 inflate(); 534 } 535 asb.getBytes(value, count, coder); 536 count += len; 537 return this; 538 } 539 540 // Documentation in subclasses because of synchro difference 541 @Override 542 public AbstractStringBuilder append(CharSequence s) { 543 if (s == null) { 544 return appendNull(); 545 } 546 if (s instanceof String) { 547 return this.append((String)s); 548 } 549 if (s instanceof AbstractStringBuilder) { 550 return this.append((AbstractStringBuilder)s); 551 } 552 return this.append(s, 0, s.length()); 553 } 554 555 private AbstractStringBuilder appendNull() { 556 ensureCapacityInternal(count + 4); 557 int count = this.count; 558 byte[] val = this.value; 559 if (isLatin1()) { 560 val[count++] = 'n'; 561 val[count++] = 'u'; 562 val[count++] = 'l'; 563 val[count++] = 'l'; 564 } else { 565 count = StringUTF16.putCharsAt(val, count, 'n', 'u', 'l', 'l'); 566 } 567 this.count = count; 568 return this; 569 } 570 571 /** 572 * Appends a subsequence of the specified {@code CharSequence} to this 573 * sequence. 574 * <p> 575 * Characters of the argument {@code s}, starting at 576 * index {@code start}, are appended, in order, to the contents of 577 * this sequence up to the (exclusive) index {@code end}. The length 578 * of this sequence is increased by the value of {@code end - start}. 579 * <p> 580 * Let <i>n</i> be the length of this character sequence just prior to 581 * execution of the {@code append} method. Then the character at 582 * index <i>k</i> in this character sequence becomes equal to the 583 * character at index <i>k</i> in this sequence, if <i>k</i> is less than 584 * <i>n</i>; otherwise, it is equal to the character at index 585 * <i>k+start-n</i> in the argument {@code s}. 586 * <p> 587 * If {@code s} is {@code null}, then this method appends 588 * characters as if the s parameter was a sequence containing the four 589 * characters {@code "null"}. 590 * 591 * @param s the sequence to append. 592 * @param start the starting index of the subsequence to be appended. 593 * @param end the end index of the subsequence to be appended. 594 * @return a reference to this object. 595 * @throws IndexOutOfBoundsException if 596 * {@code start} is negative, or 597 * {@code start} is greater than {@code end} or 598 * {@code end} is greater than {@code s.length()} 599 */ 600 @Override 601 public AbstractStringBuilder append(CharSequence s, int start, int end) { 602 if (s == null) { 603 s = "null"; 604 } 605 checkRange(start, end, s.length()); 606 int len = end - start; 607 ensureCapacityInternal(count + len); 608 appendChars(s, start, end); 609 return this; 610 } 611 612 /** 613 * Appends the string representation of the {@code char} array 614 * argument to this sequence. 615 * <p> 616 * The characters of the array argument are appended, in order, to 617 * the contents of this sequence. The length of this sequence 618 * increases by the length of the argument. 619 * <p> 620 * The overall effect is exactly as if the argument were converted 621 * to a string by the method {@link String#valueOf(char[])}, 622 * and the characters of that string were then 623 * {@link #append(String) appended} to this character sequence. 624 * 625 * @param str the characters to be appended. 626 * @return a reference to this object. 627 */ 628 public AbstractStringBuilder append(char[] str) { 629 int len = str.length; 630 ensureCapacityInternal(count + len); 631 appendChars(str, 0, len); 632 return this; 633 } 634 635 /** 636 * Appends the string representation of a subarray of the 637 * {@code char} array argument to this sequence. 638 * <p> 639 * Characters of the {@code char} array {@code str}, starting at 640 * index {@code offset}, are appended, in order, to the contents 641 * of this sequence. The length of this sequence increases 642 * by the value of {@code len}. 643 * <p> 644 * The overall effect is exactly as if the arguments were converted 645 * to a string by the method {@link String#valueOf(char[],int,int)}, 646 * and the characters of that string were then 647 * {@link #append(String) appended} to this character sequence. 648 * 649 * @param str the characters to be appended. 650 * @param offset the index of the first {@code char} to append. 651 * @param len the number of {@code char}s to append. 652 * @return a reference to this object. 653 * @throws IndexOutOfBoundsException 654 * if {@code offset < 0} or {@code len < 0} 655 * or {@code offset+len > str.length} 656 */ 657 public AbstractStringBuilder append(char str[], int offset, int len) { 658 int end = offset + len; 659 checkRange(offset, end, str.length); 660 ensureCapacityInternal(count + len); 661 appendChars(str, offset, end); 662 return this; 663 } 664 665 /** 666 * Appends the string representation of the {@code boolean} 667 * argument to the 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(boolean)}, 671 * and the characters of that string were then 672 * {@link #append(String) appended} to this character sequence. 673 * 674 * @param b a {@code boolean}. 675 * @return a reference to this object. 676 */ 677 public AbstractStringBuilder append(boolean b) { 678 ensureCapacityInternal(count + (b ? 4 : 5)); 679 int count = this.count; 680 byte[] val = this.value; 681 if (isLatin1()) { 682 if (b) { 683 val[count++] = 't'; 684 val[count++] = 'r'; 685 val[count++] = 'u'; 686 val[count++] = 'e'; 687 } else { 688 val[count++] = 'f'; 689 val[count++] = 'a'; 690 val[count++] = 'l'; 691 val[count++] = 's'; 692 val[count++] = 'e'; 693 } 694 } else { 695 if (b) { 696 count = StringUTF16.putCharsAt(val, count, 't', 'r', 'u', 'e'); 697 } else { 698 count = StringUTF16.putCharsAt(val, count, 'f', 'a', 'l', 's', 'e'); 699 } 700 } 701 this.count = count; 702 return this; 703 } 704 705 /** 706 * Appends the string representation of the {@code char} 707 * argument to this sequence. 708 * <p> 709 * The argument is appended to the contents of this sequence. 710 * The length of this sequence increases by {@code 1}. 711 * <p> 712 * The overall effect is exactly as if the argument were converted 713 * to a string by the method {@link String#valueOf(char)}, 714 * and the character in that string were then 715 * {@link #append(String) appended} to this character sequence. 716 * 717 * @param c a {@code char}. 718 * @return a reference to this object. 719 */ 720 @Override 721 public AbstractStringBuilder append(char c) { 722 ensureCapacityInternal(count + 1); 723 if (isLatin1() && StringLatin1.canEncode(c)) { 724 value[count++] = (byte)c; 725 } else { 726 if (isLatin1()) { 727 inflate(); 728 } 729 StringUTF16.putCharSB(value, count++, c); 730 } 731 return this; 732 } 733 734 /** 735 * Appends the string representation of the {@code int} 736 * argument to this sequence. 737 * <p> 738 * The overall effect is exactly as if the argument were converted 739 * to a string by the method {@link String#valueOf(int)}, 740 * and the characters of that string were then 741 * {@link #append(String) appended} to this character sequence. 742 * 743 * @param i an {@code int}. 744 * @return a reference to this object. 745 */ 746 public AbstractStringBuilder append(int i) { 747 int count = this.count; 748 int spaceNeeded = count + Integer.stringSize(i); 749 ensureCapacityInternal(spaceNeeded); 750 if (isLatin1()) { 751 Integer.getChars(i, spaceNeeded, value); 752 } else { 753 StringUTF16.getChars(i, count, spaceNeeded, value); 754 } 755 this.count = spaceNeeded; 756 return this; 757 } 758 759 /** 760 * Appends the string representation of the {@code long} 761 * argument to this sequence. 762 * <p> 763 * The overall effect is exactly as if the argument were converted 764 * to a string by the method {@link String#valueOf(long)}, 765 * and the characters of that string were then 766 * {@link #append(String) appended} to this character sequence. 767 * 768 * @param l a {@code long}. 769 * @return a reference to this object. 770 */ 771 public AbstractStringBuilder append(long l) { 772 int count = this.count; 773 int spaceNeeded = count + Long.stringSize(l); 774 ensureCapacityInternal(spaceNeeded); 775 if (isLatin1()) { 776 Long.getChars(l, spaceNeeded, value); 777 } else { 778 StringUTF16.getChars(l, count, spaceNeeded, value); 779 } 780 this.count = spaceNeeded; 781 return this; 782 } 783 784 /** 785 * Appends the string representation of the {@code float} 786 * argument to this sequence. 787 * <p> 788 * The overall effect is exactly as if the argument were converted 789 * to a string by the method {@link String#valueOf(float)}, 790 * and the characters of that string were then 791 * {@link #append(String) appended} to this character sequence. 792 * 793 * @param f a {@code float}. 794 * @return a reference to this object. 795 */ 796 public AbstractStringBuilder append(float f) { 797 FloatingDecimal.appendTo(f,this); 798 return this; 799 } 800 801 /** 802 * Appends the string representation of the {@code double} 803 * argument to this sequence. 804 * <p> 805 * The overall effect is exactly as if the argument were converted 806 * to a string by the method {@link String#valueOf(double)}, 807 * and the characters of that string were then 808 * {@link #append(String) appended} to this character sequence. 809 * 810 * @param d a {@code double}. 811 * @return a reference to this object. 812 */ 813 public AbstractStringBuilder append(double d) { 814 FloatingDecimal.appendTo(d,this); 815 return this; 816 } 817 818 /** 819 * Removes the characters in a substring of this sequence. 820 * The substring begins at the specified {@code start} and extends to 821 * the character at index {@code end - 1} or to the end of the 822 * sequence if no such character exists. If 823 * {@code start} is equal to {@code end}, no changes are made. 824 * 825 * @param start The beginning index, inclusive. 826 * @param end The ending index, exclusive. 827 * @return This object. 828 * @throws StringIndexOutOfBoundsException if {@code start} 829 * is negative, greater than {@code length()}, or 830 * greater than {@code end}. 831 */ 832 public AbstractStringBuilder delete(int start, int end) { 833 int count = this.count; 834 if (end > count) { 835 end = count; 836 } 837 checkRangeSIOOBE(start, end, count); 838 int len = end - start; 839 if (len > 0) { 840 shift(end, -len); 841 this.count = count - len; 842 } 843 return this; 844 } 845 846 /** 847 * Appends the string representation of the {@code codePoint} 848 * argument to this sequence. 849 * 850 * <p> The argument is appended to the contents of this sequence. 851 * The length of this sequence increases by 852 * {@link Character#charCount(int) Character.charCount(codePoint)}. 853 * 854 * <p> The overall effect is exactly as if the argument were 855 * converted to a {@code char} array by the method 856 * {@link Character#toChars(int)} and the character in that array 857 * were then {@link #append(char[]) appended} to this character 858 * sequence. 859 * 860 * @param codePoint a Unicode code point 861 * @return a reference to this object. 862 * @exception IllegalArgumentException if the specified 863 * {@code codePoint} isn't a valid Unicode code point 864 */ 865 public AbstractStringBuilder appendCodePoint(int codePoint) { 866 if (Character.isBmpCodePoint(codePoint)) { 867 return append((char)codePoint); 868 } 869 return append(Character.toChars(codePoint)); 870 } 871 872 /** 873 * Removes the {@code char} at the specified position in this 874 * sequence. This sequence is shortened by one {@code char}. 875 * 876 * <p>Note: If the character at the given index is a supplementary 877 * character, this method does not remove the entire character. If 878 * correct handling of supplementary characters is required, 879 * determine the number of {@code char}s to remove by calling 880 * {@code Character.charCount(thisSequence.codePointAt(index))}, 881 * where {@code thisSequence} is this sequence. 882 * 883 * @param index Index of {@code char} to remove 884 * @return This object. 885 * @throws StringIndexOutOfBoundsException if the {@code index} 886 * is negative or greater than or equal to 887 * {@code length()}. 888 */ 889 public AbstractStringBuilder deleteCharAt(int index) { 890 checkIndex(index, count); 891 shift(index + 1, -1); 892 count--; 893 return this; 894 } 895 896 /** 897 * Replaces the characters in a substring of this sequence 898 * with characters in the specified {@code String}. The substring 899 * begins at the specified {@code start} and extends to the character 900 * at index {@code end - 1} or to the end of the 901 * sequence if no such character exists. First the 902 * characters in the substring are removed and then the specified 903 * {@code String} is inserted at {@code start}. (This 904 * sequence will be lengthened to accommodate the 905 * specified String if necessary.) 906 * 907 * @param start The beginning index, inclusive. 908 * @param end The ending index, exclusive. 909 * @param str String that will replace previous contents. 910 * @return This object. 911 * @throws StringIndexOutOfBoundsException if {@code start} 912 * is negative, greater than {@code length()}, or 913 * greater than {@code end}. 914 */ 915 public AbstractStringBuilder replace(int start, int end, String str) { 916 int count = this.count; 917 if (end > count) { 918 end = count; 919 } 920 checkRangeSIOOBE(start, end, count); 921 int len = str.length(); 922 int newCount = count + len - (end - start); 923 ensureCapacityInternal(newCount); 924 shift(end, newCount - count); 925 this.count = newCount; 926 putStringAt(start, str); 927 return this; 928 } 929 930 /** 931 * Returns a new {@code String} that contains a subsequence of 932 * characters currently contained in this character sequence. The 933 * substring begins at the specified index and extends to the end of 934 * this sequence. 935 * 936 * @param start The beginning index, inclusive. 937 * @return The new string. 938 * @throws StringIndexOutOfBoundsException if {@code start} is 939 * less than zero, or greater than the length of this object. 940 */ 941 public String substring(int start) { 942 return substring(start, count); 943 } 944 945 /** 946 * Returns a new character sequence that is a subsequence of this sequence. 947 * 948 * <p> An invocation of this method of the form 949 * 950 * <pre>{@code 951 * sb.subSequence(begin, end)}</pre> 952 * 953 * behaves in exactly the same way as the invocation 954 * 955 * <pre>{@code 956 * sb.substring(begin, end)}</pre> 957 * 958 * This method is provided so that this class can 959 * implement the {@link CharSequence} interface. 960 * 961 * @param start the start index, inclusive. 962 * @param end the end index, exclusive. 963 * @return the specified subsequence. 964 * 965 * @throws IndexOutOfBoundsException 966 * if {@code start} or {@code end} are negative, 967 * if {@code end} is greater than {@code length()}, 968 * or if {@code start} is greater than {@code end} 969 * @spec JSR-51 970 */ 971 @Override 972 public CharSequence subSequence(int start, int end) { 973 return substring(start, end); 974 } 975 976 /** 977 * Returns a new {@code String} that contains a subsequence of 978 * characters currently contained in this sequence. The 979 * substring begins at the specified {@code start} and 980 * extends to the character at index {@code end - 1}. 981 * 982 * @param start The beginning index, inclusive. 983 * @param end The ending index, exclusive. 984 * @return The new string. 985 * @throws StringIndexOutOfBoundsException if {@code start} 986 * or {@code end} are negative or greater than 987 * {@code length()}, or {@code start} is 988 * greater than {@code end}. 989 */ 990 public String substring(int start, int end) { 991 checkRangeSIOOBE(start, end, count); 992 if (isLatin1()) { 993 return StringLatin1.newString(value, start, end - start); 994 } 995 return StringUTF16.newString(value, start, end - start); 996 } 997 998 private void shift(int offset, int n) { 999 System.arraycopy(value, offset << coder, 1000 value, (offset + n) << coder, (count - offset) << coder); 1001 } 1002 1003 /** 1004 * Inserts the string representation of a subarray of the {@code str} 1005 * array argument into this sequence. The subarray begins at the 1006 * specified {@code offset} and extends {@code len} {@code char}s. 1007 * The characters of the subarray are inserted into this sequence at 1008 * the position indicated by {@code index}. The length of this 1009 * sequence increases by {@code len} {@code char}s. 1010 * 1011 * @param index position at which to insert subarray. 1012 * @param str A {@code char} array. 1013 * @param offset the index of the first {@code char} in subarray to 1014 * be inserted. 1015 * @param len the number of {@code char}s in the subarray to 1016 * be inserted. 1017 * @return This object 1018 * @throws StringIndexOutOfBoundsException if {@code index} 1019 * is negative or greater than {@code length()}, or 1020 * {@code offset} or {@code len} are negative, or 1021 * {@code (offset+len)} is greater than 1022 * {@code str.length}. 1023 */ 1024 public AbstractStringBuilder insert(int index, char[] str, int offset, 1025 int len) 1026 { 1027 checkOffset(index, count); 1028 checkRangeSIOOBE(offset, offset + len, str.length); 1029 ensureCapacityInternal(count + len); 1030 shift(index, len); 1031 count += len; 1032 putCharsAt(index, str, offset, offset + len); 1033 return this; 1034 } 1035 1036 /** 1037 * Inserts the string representation of the {@code Object} 1038 * argument into this character sequence. 1039 * <p> 1040 * The overall effect is exactly as if the second argument were 1041 * converted to a string by the method {@link String#valueOf(Object)}, 1042 * and the characters of that string were then 1043 * {@link #insert(int,String) inserted} into this character 1044 * sequence at the indicated offset. 1045 * <p> 1046 * The {@code offset} argument must be greater than or equal to 1047 * {@code 0}, and less than or equal to the {@linkplain #length() length} 1048 * of this sequence. 1049 * 1050 * @param offset the offset. 1051 * @param obj an {@code Object}. 1052 * @return a reference to this object. 1053 * @throws StringIndexOutOfBoundsException if the offset is invalid. 1054 */ 1055 public AbstractStringBuilder insert(int offset, Object obj) { 1056 return insert(offset, String.valueOf(obj)); 1057 } 1058 1059 /** 1060 * Inserts the string into this character sequence. 1061 * <p> 1062 * The characters of the {@code String} argument are inserted, in 1063 * order, into this sequence at the indicated offset, moving up any 1064 * characters originally above that position and increasing the length 1065 * of this sequence by the length of the argument. If 1066 * {@code str} is {@code null}, then the four characters 1067 * {@code "null"} are inserted into this sequence. 1068 * <p> 1069 * The character at index <i>k</i> in the new character sequence is 1070 * equal to: 1071 * <ul> 1072 * <li>the character at index <i>k</i> in the old character sequence, if 1073 * <i>k</i> is less than {@code offset} 1074 * <li>the character at index <i>k</i>{@code -offset} in the 1075 * argument {@code str}, if <i>k</i> is not less than 1076 * {@code offset} but is less than {@code offset+str.length()} 1077 * <li>the character at index <i>k</i>{@code -str.length()} in the 1078 * old character sequence, if <i>k</i> is not less than 1079 * {@code offset+str.length()} 1080 * </ul><p> 1081 * The {@code offset} argument must be greater than or equal to 1082 * {@code 0}, and less than or equal to the {@linkplain #length() length} 1083 * of this sequence. 1084 * 1085 * @param offset the offset. 1086 * @param str a string. 1087 * @return a reference to this object. 1088 * @throws StringIndexOutOfBoundsException if the offset is invalid. 1089 */ 1090 public AbstractStringBuilder insert(int offset, String str) { 1091 checkOffset(offset, count); 1092 if (str == null) { 1093 str = "null"; 1094 } 1095 int len = str.length(); 1096 ensureCapacityInternal(count + len); 1097 shift(offset, len); 1098 count += len; 1099 putStringAt(offset, str); 1100 return this; 1101 } 1102 1103 /** 1104 * Inserts the string representation of the {@code char} array 1105 * argument into this sequence. 1106 * <p> 1107 * The characters of the array argument are inserted into the 1108 * contents of this sequence at the position indicated by 1109 * {@code offset}. The length of this sequence increases by 1110 * the length of the argument. 1111 * <p> 1112 * The overall effect is exactly as if the second argument were 1113 * converted to a string by the method {@link String#valueOf(char[])}, 1114 * and the characters of that string were then 1115 * {@link #insert(int,String) inserted} into this character 1116 * sequence at the indicated offset. 1117 * <p> 1118 * The {@code offset} argument must be greater than or equal to 1119 * {@code 0}, and less than or equal to the {@linkplain #length() length} 1120 * of this sequence. 1121 * 1122 * @param offset the offset. 1123 * @param str a character array. 1124 * @return a reference to this object. 1125 * @throws StringIndexOutOfBoundsException if the offset is invalid. 1126 */ 1127 public AbstractStringBuilder insert(int offset, char[] str) { 1128 checkOffset(offset, count); 1129 int len = str.length; 1130 ensureCapacityInternal(count + len); 1131 shift(offset, len); 1132 count += len; 1133 putCharsAt(offset, str, 0, len); 1134 return this; 1135 } 1136 1137 /** 1138 * Inserts the specified {@code CharSequence} into this sequence. 1139 * <p> 1140 * The characters of the {@code CharSequence} argument are inserted, 1141 * in order, into this sequence at the indicated offset, moving up 1142 * any characters originally above that position and increasing the length 1143 * of this sequence by the length of the argument s. 1144 * <p> 1145 * The result of this method is exactly the same as if it were an 1146 * invocation of this object's 1147 * {@link #insert(int,CharSequence,int,int) insert}(dstOffset, s, 0, s.length()) 1148 * method. 1149 * 1150 * <p>If {@code s} is {@code null}, then the four characters 1151 * {@code "null"} are inserted into this sequence. 1152 * 1153 * @param dstOffset the offset. 1154 * @param s the sequence to be inserted 1155 * @return a reference to this object. 1156 * @throws IndexOutOfBoundsException if the offset is invalid. 1157 */ 1158 public AbstractStringBuilder insert(int dstOffset, CharSequence s) { 1159 if (s == null) { 1160 s = "null"; 1161 } 1162 if (s instanceof String) { 1163 return this.insert(dstOffset, (String)s); 1164 } 1165 return this.insert(dstOffset, s, 0, s.length()); 1166 } 1167 1168 /** 1169 * Inserts a subsequence of the specified {@code CharSequence} into 1170 * this sequence. 1171 * <p> 1172 * The subsequence of the argument {@code s} specified by 1173 * {@code start} and {@code end} are inserted, 1174 * in order, into this sequence at the specified destination offset, moving 1175 * up any characters originally above that position. The length of this 1176 * sequence is increased by {@code end - start}. 1177 * <p> 1178 * The character at index <i>k</i> in this sequence becomes equal to: 1179 * <ul> 1180 * <li>the character at index <i>k</i> in this sequence, if 1181 * <i>k</i> is less than {@code dstOffset} 1182 * <li>the character at index <i>k</i>{@code +start-dstOffset} in 1183 * the argument {@code s}, if <i>k</i> is greater than or equal to 1184 * {@code dstOffset} but is less than {@code dstOffset+end-start} 1185 * <li>the character at index <i>k</i>{@code -(end-start)} in this 1186 * sequence, if <i>k</i> is greater than or equal to 1187 * {@code dstOffset+end-start} 1188 * </ul><p> 1189 * The {@code dstOffset} argument must be greater than or equal to 1190 * {@code 0}, and less than or equal to the {@linkplain #length() length} 1191 * of this sequence. 1192 * <p>The start argument must be nonnegative, and not greater than 1193 * {@code end}. 1194 * <p>The end argument must be greater than or equal to 1195 * {@code start}, and less than or equal to the length of s. 1196 * 1197 * <p>If {@code s} is {@code null}, then this method inserts 1198 * characters as if the s parameter was a sequence containing the four 1199 * characters {@code "null"}. 1200 * 1201 * @param dstOffset the offset in this sequence. 1202 * @param s the sequence to be inserted. 1203 * @param start the starting index of the subsequence to be inserted. 1204 * @param end the end index of the subsequence to be inserted. 1205 * @return a reference to this object. 1206 * @throws IndexOutOfBoundsException if {@code dstOffset} 1207 * is negative or greater than {@code this.length()}, or 1208 * {@code start} or {@code end} are negative, or 1209 * {@code start} is greater than {@code end} or 1210 * {@code end} is greater than {@code s.length()} 1211 */ 1212 public AbstractStringBuilder insert(int dstOffset, CharSequence s, 1213 int start, int end) 1214 { 1215 if (s == null) { 1216 s = "null"; 1217 } 1218 checkOffset(dstOffset, count); 1219 checkRange(start, end, s.length()); 1220 int len = end - start; 1221 ensureCapacityInternal(count + len); 1222 shift(dstOffset, len); 1223 count += len; 1224 putCharsAt(dstOffset, s, start, end); 1225 return this; 1226 } 1227 1228 /** 1229 * Inserts the string representation of the {@code boolean} 1230 * argument into this sequence. 1231 * <p> 1232 * The overall effect is exactly as if the second argument were 1233 * converted to a string by the method {@link String#valueOf(boolean)}, 1234 * and the characters of that string were then 1235 * {@link #insert(int,String) inserted} into this character 1236 * sequence at the indicated offset. 1237 * <p> 1238 * The {@code offset} argument must be greater than or equal to 1239 * {@code 0}, and less than or equal to the {@linkplain #length() length} 1240 * of this sequence. 1241 * 1242 * @param offset the offset. 1243 * @param b a {@code boolean}. 1244 * @return a reference to this object. 1245 * @throws StringIndexOutOfBoundsException if the offset is invalid. 1246 */ 1247 public AbstractStringBuilder insert(int offset, boolean b) { 1248 return insert(offset, String.valueOf(b)); 1249 } 1250 1251 /** 1252 * Inserts the string representation of the {@code char} 1253 * argument into this sequence. 1254 * <p> 1255 * The overall effect is exactly as if the second argument were 1256 * converted to a string by the method {@link String#valueOf(char)}, 1257 * and the character in that string were then 1258 * {@link #insert(int,String) inserted} into this character 1259 * sequence at the indicated offset. 1260 * <p> 1261 * The {@code offset} argument must be greater than or equal to 1262 * {@code 0}, and less than or equal to the {@linkplain #length() length} 1263 * of this sequence. 1264 * 1265 * @param offset the offset. 1266 * @param c a {@code char}. 1267 * @return a reference to this object. 1268 * @throws IndexOutOfBoundsException if the offset is invalid. 1269 */ 1270 public AbstractStringBuilder insert(int offset, char c) { 1271 checkOffset(offset, count); 1272 ensureCapacityInternal(count + 1); 1273 shift(offset, 1); 1274 count += 1; 1275 if (isLatin1() && StringLatin1.canEncode(c)) { 1276 value[offset] = (byte)c; 1277 } else { 1278 if (isLatin1()) { 1279 inflate(); 1280 } 1281 StringUTF16.putCharSB(value, offset, c); 1282 } 1283 return this; 1284 } 1285 1286 /** 1287 * Inserts the string representation of the second {@code int} 1288 * argument into this sequence. 1289 * <p> 1290 * The overall effect is exactly as if the second argument were 1291 * converted to a string by the method {@link String#valueOf(int)}, 1292 * and the characters of that string were then 1293 * {@link #insert(int,String) inserted} into this character 1294 * sequence at the indicated offset. 1295 * <p> 1296 * The {@code offset} argument must be greater than or equal to 1297 * {@code 0}, and less than or equal to the {@linkplain #length() length} 1298 * of this sequence. 1299 * 1300 * @param offset the offset. 1301 * @param i an {@code int}. 1302 * @return a reference to this object. 1303 * @throws StringIndexOutOfBoundsException if the offset is invalid. 1304 */ 1305 public AbstractStringBuilder insert(int offset, int i) { 1306 return insert(offset, String.valueOf(i)); 1307 } 1308 1309 /** 1310 * Inserts the string representation of the {@code long} 1311 * argument into this sequence. 1312 * <p> 1313 * The overall effect is exactly as if the second argument were 1314 * converted to a string by the method {@link String#valueOf(long)}, 1315 * and the characters of that string were then 1316 * {@link #insert(int,String) inserted} into this character 1317 * sequence at the indicated offset. 1318 * <p> 1319 * The {@code offset} argument must be greater than or equal to 1320 * {@code 0}, and less than or equal to the {@linkplain #length() length} 1321 * of this sequence. 1322 * 1323 * @param offset the offset. 1324 * @param l a {@code long}. 1325 * @return a reference to this object. 1326 * @throws StringIndexOutOfBoundsException if the offset is invalid. 1327 */ 1328 public AbstractStringBuilder insert(int offset, long l) { 1329 return insert(offset, String.valueOf(l)); 1330 } 1331 1332 /** 1333 * Inserts the string representation of the {@code float} 1334 * argument into this sequence. 1335 * <p> 1336 * The overall effect is exactly as if the second argument were 1337 * converted to a string by the method {@link String#valueOf(float)}, 1338 * and the characters of that string were then 1339 * {@link #insert(int,String) inserted} into this character 1340 * sequence at the indicated offset. 1341 * <p> 1342 * The {@code offset} argument must be greater than or equal to 1343 * {@code 0}, and less than or equal to the {@linkplain #length() length} 1344 * of this sequence. 1345 * 1346 * @param offset the offset. 1347 * @param f a {@code float}. 1348 * @return a reference to this object. 1349 * @throws StringIndexOutOfBoundsException if the offset is invalid. 1350 */ 1351 public AbstractStringBuilder insert(int offset, float f) { 1352 return insert(offset, String.valueOf(f)); 1353 } 1354 1355 /** 1356 * Inserts the string representation of the {@code double} 1357 * argument into this sequence. 1358 * <p> 1359 * The overall effect is exactly as if the second argument were 1360 * converted to a string by the method {@link String#valueOf(double)}, 1361 * and the characters of that string were then 1362 * {@link #insert(int,String) inserted} into this character 1363 * sequence at the indicated offset. 1364 * <p> 1365 * The {@code offset} argument must be greater than or equal to 1366 * {@code 0}, and less than or equal to the {@linkplain #length() length} 1367 * of this sequence. 1368 * 1369 * @param offset the offset. 1370 * @param d a {@code double}. 1371 * @return a reference to this object. 1372 * @throws StringIndexOutOfBoundsException if the offset is invalid. 1373 */ 1374 public AbstractStringBuilder insert(int offset, double d) { 1375 return insert(offset, String.valueOf(d)); 1376 } 1377 1378 /** 1379 * Returns the index within this string of the first occurrence of the 1380 * specified substring. 1381 * 1382 * <p>The returned index is the smallest value {@code k} for which: 1383 * <pre>{@code 1384 * this.toString().startsWith(str, k) 1385 * }</pre> 1386 * If no such value of {@code k} exists, then {@code -1} is returned. 1387 * 1388 * @param str the substring to search for. 1389 * @return the index of the first occurrence of the specified substring, 1390 * or {@code -1} if there is no such occurrence. 1391 */ 1392 public int indexOf(String str) { 1393 return indexOf(str, 0); 1394 } 1395 1396 /** 1397 * Returns the index within this string of the first occurrence of the 1398 * specified substring, starting at the specified index. 1399 * 1400 * <p>The returned index is the smallest value {@code k} for which: 1401 * <pre>{@code 1402 * k >= Math.min(fromIndex, this.length()) && 1403 * this.toString().startsWith(str, k) 1404 * }</pre> 1405 * If no such value of {@code k} exists, then {@code -1} is returned. 1406 * 1407 * @param str the substring to search for. 1408 * @param fromIndex the index from which to start the search. 1409 * @return the index of the first occurrence of the specified substring, 1410 * starting at the specified index, 1411 * or {@code -1} if there is no such occurrence. 1412 */ 1413 public int indexOf(String str, int fromIndex) { 1414 return String.indexOf(value, coder, count, str, fromIndex); 1415 } 1416 1417 /** 1418 * Returns the index within this string of the last occurrence of the 1419 * specified substring. The last occurrence of the empty string "" is 1420 * considered to occur at the index value {@code this.length()}. 1421 * 1422 * <p>The returned index is the largest value {@code k} for which: 1423 * <pre>{@code 1424 * this.toString().startsWith(str, k) 1425 * }</pre> 1426 * If no such value of {@code k} exists, then {@code -1} is returned. 1427 * 1428 * @param str the substring to search for. 1429 * @return the index of the last occurrence of the specified substring, 1430 * or {@code -1} if there is no such occurrence. 1431 */ 1432 public int lastIndexOf(String str) { 1433 return lastIndexOf(str, count); 1434 } 1435 1436 /** 1437 * Returns the index within this string of the last occurrence of the 1438 * specified substring, searching backward starting at the specified index. 1439 * 1440 * <p>The returned index is the largest value {@code k} for which: 1441 * <pre>{@code 1442 * k <= Math.min(fromIndex, this.length()) && 1443 * this.toString().startsWith(str, k) 1444 * }</pre> 1445 * If no such value of {@code k} exists, then {@code -1} is returned. 1446 * 1447 * @param str the substring to search for. 1448 * @param fromIndex the index to start the search from. 1449 * @return the index of the last occurrence of the specified substring, 1450 * searching backward from the specified index, 1451 * or {@code -1} if there is no such occurrence. 1452 */ 1453 public int lastIndexOf(String str, int fromIndex) { 1454 return String.lastIndexOf(value, coder, count, str, fromIndex); 1455 } 1456 1457 /** 1458 * Causes this character sequence to be replaced by the reverse of 1459 * the sequence. If there are any surrogate pairs included in the 1460 * sequence, these are treated as single characters for the 1461 * reverse operation. Thus, the order of the high-low surrogates 1462 * is never reversed. 1463 * 1464 * Let <i>n</i> be the character length of this character sequence 1465 * (not the length in {@code char} values) just prior to 1466 * execution of the {@code reverse} method. Then the 1467 * character at index <i>k</i> in the new character sequence is 1468 * equal to the character at index <i>n-k-1</i> in the old 1469 * character sequence. 1470 * 1471 * <p>Note that the reverse operation may result in producing 1472 * surrogate pairs that were unpaired low-surrogates and 1473 * high-surrogates before the operation. For example, reversing 1474 * "\u005CuDC00\u005CuD800" produces "\u005CuD800\u005CuDC00" which is 1475 * a valid surrogate pair. 1476 * 1477 * @return a reference to this object. 1478 */ 1479 public AbstractStringBuilder reverse() { 1480 byte[] val = this.value; 1481 int count = this.count; 1482 int coder = this.coder; 1483 int n = count - 1; 1484 if (COMPACT_STRINGS && coder == LATIN1) { 1485 for (int j = (n-1) >> 1; j >= 0; j--) { 1486 int k = n - j; 1487 byte cj = val[j]; 1488 val[j] = val[k]; 1489 val[k] = cj; 1490 } 1491 } else { 1492 StringUTF16.reverse(val, count); 1493 } 1494 return this; 1495 } 1496 1497 /** 1498 * Returns a string representing the data in this sequence. 1499 * A new {@code String} object is allocated and initialized to 1500 * contain the character sequence currently represented by this 1501 * object. This {@code String} is then returned. Subsequent 1502 * changes to this sequence do not affect the contents of the 1503 * {@code String}. 1504 * 1505 * @return a string representation of this sequence of characters. 1506 */ 1507 @Override 1508 public abstract String toString(); 1509 1510 /** 1511 * {@inheritDoc} 1512 * @since 9 1513 */ 1514 @Override 1515 public IntStream chars() { 1516 // Reuse String-based spliterator. This requires a supplier to 1517 // capture the value and count when the terminal operation is executed 1518 return StreamSupport.intStream( 1519 () -> { 1520 // The combined set of field reads are not atomic and thread 1521 // safe but bounds checks will ensure no unsafe reads from 1522 // the byte array 1523 byte[] val = this.value; 1524 int count = this.count; 1525 byte coder = this.coder; 1526 return coder == LATIN1 1527 ? new StringLatin1.CharsSpliterator(val, 0, count, 0) 1528 : new StringUTF16.CharsSpliterator(val, 0, count, 0); 1529 }, 1530 Spliterator.ORDERED | Spliterator.SIZED | Spliterator.SUBSIZED, 1531 false); 1532 } 1533 1534 /** 1535 * {@inheritDoc} 1536 * @since 9 1537 */ 1538 @Override 1539 public IntStream codePoints() { 1540 // Reuse String-based spliterator. This requires a supplier to 1541 // capture the value and count when the terminal operation is executed 1542 return StreamSupport.intStream( 1543 () -> { 1544 // The combined set of field reads are not atomic and thread 1545 // safe but bounds checks will ensure no unsafe reads from 1546 // the byte array 1547 byte[] val = this.value; 1548 int count = this.count; 1549 byte coder = this.coder; 1550 return coder == LATIN1 1551 ? new StringLatin1.CharsSpliterator(val, 0, count, 0) 1552 : new StringUTF16.CodePointsSpliterator(val, 0, count, 0); 1553 }, 1554 Spliterator.ORDERED, 1555 false); 1556 } 1557 1558 /** 1559 * Needed by {@code String} for the contentEquals method. 1560 */ 1561 final byte[] getValue() { 1562 return value; 1563 } 1564 1565 /* 1566 * Invoker guarantees it is in UTF16 (inflate itself for asb), if two 1567 * coders are different and the dstBegin has enough space 1568 * 1569 * @param dstBegin the char index, not offset of byte[] 1570 * @param coder the coder of dst[] 1571 */ 1572 void getBytes(byte dst[], int dstBegin, byte coder) { 1573 if (this.coder == coder) { 1574 System.arraycopy(value, 0, dst, dstBegin << coder, count << coder); 1575 } else { // this.coder == LATIN && coder == UTF16 1576 StringLatin1.inflate(value, 0, dst, dstBegin, count); 1577 } 1578 } 1579 1580 /* for readObject() */ 1581 void initBytes(char[] value, int off, int len) { 1582 if (String.COMPACT_STRINGS) { 1583 this.value = StringUTF16.compress(value, off, len); 1584 if (this.value != null) { 1585 this.coder = LATIN1; 1586 return; 1587 } 1588 } 1589 this.coder = UTF16; 1590 this.value = StringUTF16.toBytes(value, off, len); 1591 } 1592 1593 final byte getCoder() { 1594 return COMPACT_STRINGS ? coder : UTF16; 1595 } 1596 1597 final boolean isLatin1() { 1598 return COMPACT_STRINGS && coder == LATIN1; 1599 } 1600 1601 private final void putCharsAt(int index, char[] s, int off, int end) { 1602 if (isLatin1()) { 1603 byte[] val = this.value; 1604 for (int i = off, j = index; i < end; i++) { 1605 char c = s[i]; 1606 if (StringLatin1.canEncode(c)) { 1607 val[j++] = (byte)c; 1608 } else { 1609 inflate(); 1610 StringUTF16.putCharsSB(this.value, j, s, i, end); 1611 return; 1612 } 1613 } 1614 } else { 1615 StringUTF16.putCharsSB(this.value, index, s, off, end); 1616 } 1617 } 1618 1619 private final void putCharsAt(int index, CharSequence s, int off, int end) { 1620 if (isLatin1()) { 1621 byte[] val = this.value; 1622 for (int i = off, j = index; i < end; i++) { 1623 char c = s.charAt(i); 1624 if (StringLatin1.canEncode(c)) { 1625 val[j++] = (byte)c; 1626 } else { 1627 inflate(); 1628 StringUTF16.putCharsSB(this.value, j, s, i, end); 1629 return; 1630 } 1631 } 1632 } else { 1633 StringUTF16.putCharsSB(this.value, index, s, off, end); 1634 } 1635 } 1636 1637 private final void putStringAt(int index, String str) { 1638 if (getCoder() != str.coder()) { 1639 inflate(); 1640 } 1641 str.getBytes(value, index, coder); 1642 } 1643 1644 private final void appendChars(char[] s, int off, int end) { 1645 int count = this.count; 1646 if (isLatin1()) { 1647 byte[] val = this.value; 1648 for (int i = off, j = count; i < end; i++) { 1649 char c = s[i]; 1650 if (StringLatin1.canEncode(c)) { 1651 val[j++] = (byte)c; 1652 } else { 1653 this.count = count = j; 1654 inflate(); 1655 StringUTF16.putCharsSB(this.value, j, s, i, end); 1656 this.count = count + end - i; 1657 return; 1658 } 1659 } 1660 } else { 1661 StringUTF16.putCharsSB(this.value, count, s, off, end); 1662 } 1663 this.count = count + end - off; 1664 } 1665 1666 private final void appendChars(CharSequence s, int off, int end) { 1667 if (isLatin1()) { 1668 byte[] val = this.value; 1669 for (int i = off, j = count; i < end; i++) { 1670 char c = s.charAt(i); 1671 if (StringLatin1.canEncode(c)) { 1672 val[j++] = (byte)c; 1673 } else { 1674 count = j; 1675 inflate(); 1676 StringUTF16.putCharsSB(this.value, j, s, i, end); 1677 count += end - i; 1678 return; 1679 } 1680 } 1681 } else { 1682 StringUTF16.putCharsSB(this.value, count, s, off, end); 1683 } 1684 count += end - off; 1685 } 1686 1687 /* IndexOutOfBoundsException, if out of bounds */ 1688 private static void checkRange(int start, int end, int len) { 1689 if (start < 0 || start > end || end > len) { 1690 throw new IndexOutOfBoundsException( 1691 "start " + start + ", end " + end + ", length " + len); 1692 } 1693 } 1694 1695 /* StringIndexOutOfBoundsException, if out of bounds */ 1696 private static void checkRangeSIOOBE(int start, int end, int len) { 1697 if (start < 0 || start > end || end > len) { 1698 throw new StringIndexOutOfBoundsException( 1699 "start " + start + ", end " + end + ", length " + len); 1700 } 1701 } 1702} 1703