1 /* 2 * Copyright (c) 2003, 2020, 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 26 package java.lang; 27 28 import jdk.internal.math.FloatingDecimal; 29 30 import java.util.Arrays; 31 import java.util.Spliterator; 32 import java.util.stream.IntStream; 33 import java.util.stream.StreamSupport; 34 import jdk.internal.util.ArraysSupport; 35 36 import static java.lang.String.COMPACT_STRINGS; 37 import static java.lang.String.UTF16; 38 import static java.lang.String.LATIN1; 39 import static java.lang.String.checkIndex; 40 import static java.lang.String.checkOffset; 41 42 /** 43 * A mutable sequence of characters. 44 * <p> 45 * Implements a modifiable string. At any point in time it contains some 46 * particular sequence of characters, but the length and content of the 47 * sequence can be changed through certain method calls. 48 * 49 * <p>Unless otherwise noted, passing a {@code null} argument to a constructor 50 * or method in this class will cause a {@link NullPointerException} to be 51 * thrown. 52 * 53 * @author Michael McCloskey 54 * @author Martin Buchholz 55 * @author Ulf Zibis 56 * @since 1.5 57 */ 58 abstract class AbstractStringBuilder implements Appendable, CharSequence { 59 /** 60 * The value is used for character storage. 61 */ 62 byte[] value; 63 64 /** 65 * The id of the encoding used to encode the bytes in {@code value}. 66 */ 67 byte coder; 68 69 /** 70 * The count is the number of characters used. 71 */ 72 int count; 73 74 private static final byte[] EMPTYVALUE = new byte[0]; 75 76 /** 77 * This no-arg constructor is necessary for serialization of subclasses. 78 */ AbstractStringBuilder()79 AbstractStringBuilder() { 80 value = EMPTYVALUE; 81 } 82 83 /** 84 * Creates an AbstractStringBuilder of the specified capacity. 85 */ AbstractStringBuilder(int capacity)86 AbstractStringBuilder(int capacity) { 87 if (COMPACT_STRINGS) { 88 value = new byte[capacity]; 89 coder = LATIN1; 90 } else { 91 value = StringUTF16.newBytesFor(capacity); 92 coder = UTF16; 93 } 94 } 95 96 /** 97 * Constructs an AbstractStringBuilder that contains the same characters 98 * as the specified {@code String}. The initial capacity of 99 * the string builder is {@code 16} plus the length of the 100 * {@code String} argument. 101 * 102 * @param str the string to copy. 103 */ AbstractStringBuilder(String str)104 AbstractStringBuilder(String str) { 105 int length = str.length(); 106 int capacity = (length < Integer.MAX_VALUE - 16) 107 ? length + 16 : Integer.MAX_VALUE; 108 final byte initCoder = str.coder(); 109 coder = initCoder; 110 value = (initCoder == LATIN1) 111 ? new byte[capacity] : StringUTF16.newBytesFor(capacity); 112 append(str); 113 } 114 115 /** 116 * Constructs an AbstractStringBuilder that contains the same characters 117 * as the specified {@code CharSequence}. The initial capacity of 118 * the string builder is {@code 16} plus the length of the 119 * {@code CharSequence} argument. 120 * 121 * @param seq the sequence to copy. 122 */ AbstractStringBuilder(CharSequence seq)123 AbstractStringBuilder(CharSequence seq) { 124 int length = seq.length(); 125 if (length < 0) { 126 throw new NegativeArraySizeException("Negative length: " + length); 127 } 128 int capacity = (length < Integer.MAX_VALUE - 16) 129 ? length + 16 : Integer.MAX_VALUE; 130 131 final byte initCoder; 132 if (COMPACT_STRINGS) { 133 if (seq instanceof AbstractStringBuilder) { 134 initCoder = ((AbstractStringBuilder)seq).getCoder(); 135 } else if (seq instanceof String) { 136 initCoder = ((String)seq).coder(); 137 } else { 138 initCoder = LATIN1; 139 } 140 } else { 141 initCoder = UTF16; 142 } 143 144 coder = initCoder; 145 value = (initCoder == LATIN1) 146 ? new byte[capacity] : StringUTF16.newBytesFor(capacity); 147 append(seq); 148 } 149 150 /** 151 * Compares the objects of two AbstractStringBuilder implementations lexicographically. 152 * 153 * @since 11 154 */ compareTo(AbstractStringBuilder another)155 int compareTo(AbstractStringBuilder another) { 156 if (this == another) { 157 return 0; 158 } 159 160 byte[] val1 = value; 161 byte[] val2 = another.value; 162 int count1 = this.count; 163 int count2 = another.count; 164 165 if (coder == another.coder) { 166 return isLatin1() ? StringLatin1.compareTo(val1, val2, count1, count2) 167 : StringUTF16.compareTo(val1, val2, count1, count2); 168 } 169 return isLatin1() ? StringLatin1.compareToUTF16(val1, val2, count1, count2) 170 : StringUTF16.compareToLatin1(val1, val2, count1, count2); 171 } 172 173 /** 174 * Returns the length (character count). 175 * 176 * @return the length of the sequence of characters currently 177 * represented by this object 178 */ 179 @Override length()180 public int length() { 181 return count; 182 } 183 184 /** 185 * Returns the current capacity. The capacity is the number of characters 186 * that can be stored (including already written characters), beyond which 187 * an allocation will occur. 188 * 189 * @return the current capacity 190 */ capacity()191 public int capacity() { 192 return value.length >> coder; 193 } 194 195 /** 196 * Ensures that the capacity is at least equal to the specified minimum. 197 * If the current capacity is less than the argument, then a new internal 198 * array is allocated with greater capacity. The new capacity is the 199 * larger of: 200 * <ul> 201 * <li>The {@code minimumCapacity} argument. 202 * <li>Twice the old capacity, plus {@code 2}. 203 * </ul> 204 * If the {@code minimumCapacity} argument is nonpositive, this 205 * method takes no action and simply returns. 206 * Note that subsequent operations on this object can reduce the 207 * actual capacity below that requested here. 208 * 209 * @param minimumCapacity the minimum desired capacity. 210 */ ensureCapacity(int minimumCapacity)211 public void ensureCapacity(int minimumCapacity) { 212 if (minimumCapacity > 0) { 213 ensureCapacityInternal(minimumCapacity); 214 } 215 } 216 217 /** 218 * For positive values of {@code minimumCapacity}, this method 219 * behaves like {@code ensureCapacity}, however it is never 220 * synchronized. 221 * If {@code minimumCapacity} is non positive due to numeric 222 * overflow, this method throws {@code OutOfMemoryError}. 223 */ ensureCapacityInternal(int minimumCapacity)224 private void ensureCapacityInternal(int minimumCapacity) { 225 // overflow-conscious code 226 int oldCapacity = value.length >> coder; 227 if (minimumCapacity - oldCapacity > 0) { 228 value = Arrays.copyOf(value, 229 newCapacity(minimumCapacity) << coder); 230 } 231 } 232 233 /** 234 * The maximum size of array to allocate (unless necessary). 235 * Some VMs reserve some header words in an array. 236 * Attempts to allocate larger arrays may result in 237 * OutOfMemoryError: Requested array size exceeds VM limit 238 */ 239 private static final int MAX_ARRAY_SIZE = Integer.MAX_VALUE - 8; 240 241 /** 242 * Returns a capacity at least as large as the given minimum capacity. 243 * Returns the current capacity increased by the current length + 2 if 244 * that suffices. 245 * Will not return a capacity greater than 246 * {@code (MAX_ARRAY_SIZE >> coder)} unless the given minimum capacity 247 * is greater than that. 248 * 249 * @param minCapacity the desired minimum capacity 250 * @throws OutOfMemoryError if minCapacity is less than zero or 251 * greater than (Integer.MAX_VALUE >> coder) 252 */ newCapacity(int minCapacity)253 private int newCapacity(int minCapacity) { 254 int oldLength = value.length; 255 int newLength = minCapacity << coder; 256 int growth = newLength - oldLength; 257 int length = ArraysSupport.newLength(oldLength, growth, oldLength + (2 << coder)); 258 if (length == Integer.MAX_VALUE) { 259 throw new OutOfMemoryError("Required length exceeds implementation limit"); 260 } 261 return length >> coder; 262 } 263 264 /** 265 * If the coder is "isLatin1", this inflates the internal 8-bit storage 266 * to 16-bit <hi=0, low> pair storage. 267 */ inflate()268 private void inflate() { 269 if (!isLatin1()) { 270 return; 271 } 272 byte[] buf = StringUTF16.newBytesFor(value.length); 273 StringLatin1.inflate(value, 0, buf, 0, count); 274 this.value = buf; 275 this.coder = UTF16; 276 } 277 278 /** 279 * Attempts to reduce storage used for the character sequence. 280 * If the buffer is larger than necessary to hold its current sequence of 281 * characters, then it may be resized to become more space efficient. 282 * Calling this method may, but is not required to, affect the value 283 * returned by a subsequent call to the {@link #capacity()} method. 284 */ trimToSize()285 public void trimToSize() { 286 int length = count << coder; 287 if (length < value.length) { 288 value = Arrays.copyOf(value, length); 289 } 290 } 291 292 /** 293 * Sets the length of the character sequence. 294 * The sequence is changed to a new character sequence 295 * whose length is specified by the argument. For every nonnegative 296 * index <i>k</i> less than {@code newLength}, the character at 297 * index <i>k</i> in the new character sequence is the same as the 298 * character at index <i>k</i> in the old sequence if <i>k</i> is less 299 * than the length of the old character sequence; otherwise, it is the 300 * null character {@code '\u005Cu0000'}. 301 * 302 * In other words, if the {@code newLength} argument is less than 303 * the current length, the length is changed to the specified length. 304 * <p> 305 * If the {@code newLength} argument is greater than or equal 306 * to the current length, sufficient null characters 307 * ({@code '\u005Cu0000'}) are appended so that 308 * length becomes the {@code newLength} argument. 309 * <p> 310 * The {@code newLength} argument must be greater than or equal 311 * to {@code 0}. 312 * 313 * @param newLength the new length 314 * @throws IndexOutOfBoundsException if the 315 * {@code newLength} argument is negative. 316 */ setLength(int newLength)317 public void setLength(int newLength) { 318 if (newLength < 0) { 319 throw new StringIndexOutOfBoundsException(newLength); 320 } 321 ensureCapacityInternal(newLength); 322 if (count < newLength) { 323 if (isLatin1()) { 324 StringLatin1.fillNull(value, count, newLength); 325 } else { 326 StringUTF16.fillNull(value, count, newLength); 327 } 328 } 329 count = newLength; 330 } 331 332 /** 333 * Returns the {@code char} value in this sequence at the specified index. 334 * The first {@code char} value is at index {@code 0}, the next at index 335 * {@code 1}, and so on, as in array indexing. 336 * <p> 337 * The index argument must be greater than or equal to 338 * {@code 0}, and less than the length of this sequence. 339 * 340 * <p>If the {@code char} value specified by the index is a 341 * <a href="Character.html#unicode">surrogate</a>, the surrogate 342 * value is returned. 343 * 344 * @param index the index of the desired {@code char} value. 345 * @return the {@code char} value at the specified index. 346 * @throws IndexOutOfBoundsException if {@code index} is 347 * negative or greater than or equal to {@code length()}. 348 */ 349 @Override charAt(int index)350 public char charAt(int index) { 351 checkIndex(index, count); 352 if (isLatin1()) { 353 return (char)(value[index] & 0xff); 354 } 355 return StringUTF16.charAt(value, index); 356 } 357 358 /** 359 * Returns the character (Unicode code point) at the specified 360 * index. The index refers to {@code char} values 361 * (Unicode code units) and ranges from {@code 0} to 362 * {@link #length()}{@code - 1}. 363 * 364 * <p> If the {@code char} value specified at the given index 365 * is in the high-surrogate range, the following index is less 366 * than the length of this sequence, and the 367 * {@code char} value at the following index is in the 368 * low-surrogate range, then the supplementary code point 369 * corresponding to this surrogate pair is returned. Otherwise, 370 * the {@code char} value at the given index is returned. 371 * 372 * @param index the index to the {@code char} values 373 * @return the code point value of the character at the 374 * {@code index} 375 * @throws IndexOutOfBoundsException if the {@code index} 376 * argument is negative or not less than the length of this 377 * sequence. 378 */ codePointAt(int index)379 public int codePointAt(int index) { 380 int count = this.count; 381 byte[] value = this.value; 382 checkIndex(index, count); 383 if (isLatin1()) { 384 return value[index] & 0xff; 385 } 386 return StringUTF16.codePointAtSB(value, index, count); 387 } 388 389 /** 390 * Returns the character (Unicode code point) before the specified 391 * index. The index refers to {@code char} values 392 * (Unicode code units) and ranges from {@code 1} to {@link 393 * #length()}. 394 * 395 * <p> If the {@code char} value at {@code (index - 1)} 396 * is in the low-surrogate range, {@code (index - 2)} is not 397 * negative, and the {@code char} value at {@code (index - 398 * 2)} is in the high-surrogate range, then the 399 * supplementary code point value of the surrogate pair is 400 * returned. If the {@code char} value at {@code index - 401 * 1} is an unpaired low-surrogate or a high-surrogate, the 402 * surrogate value is returned. 403 * 404 * @param index the index following the code point that should be returned 405 * @return the Unicode code point value before the given index. 406 * @throws IndexOutOfBoundsException if the {@code index} 407 * argument is less than 1 or greater than the length 408 * of this sequence. 409 */ codePointBefore(int index)410 public int codePointBefore(int index) { 411 int i = index - 1; 412 if (i < 0 || i >= count) { 413 throw new StringIndexOutOfBoundsException(index); 414 } 415 if (isLatin1()) { 416 return value[i] & 0xff; 417 } 418 return StringUTF16.codePointBeforeSB(value, index); 419 } 420 421 /** 422 * Returns the number of Unicode code points in the specified text 423 * range of this sequence. The text range begins at the specified 424 * {@code beginIndex} and extends to the {@code char} at 425 * index {@code endIndex - 1}. Thus the length (in 426 * {@code char}s) of the text range is 427 * {@code endIndex-beginIndex}. Unpaired surrogates within 428 * this sequence count as one code point each. 429 * 430 * @param beginIndex the index to the first {@code char} of 431 * the text range. 432 * @param endIndex the index after the last {@code char} of 433 * the text range. 434 * @return the number of Unicode code points in the specified text 435 * range 436 * @throws IndexOutOfBoundsException if the 437 * {@code beginIndex} is negative, or {@code endIndex} 438 * is larger than the length of this sequence, or 439 * {@code beginIndex} is larger than {@code endIndex}. 440 */ codePointCount(int beginIndex, int endIndex)441 public int codePointCount(int beginIndex, int endIndex) { 442 if (beginIndex < 0 || endIndex > count || beginIndex > endIndex) { 443 throw new IndexOutOfBoundsException(); 444 } 445 if (isLatin1()) { 446 return endIndex - beginIndex; 447 } 448 return StringUTF16.codePointCountSB(value, beginIndex, endIndex); 449 } 450 451 /** 452 * Returns the index within this sequence that is offset from the 453 * given {@code index} by {@code codePointOffset} code 454 * points. Unpaired surrogates within the text range given by 455 * {@code index} and {@code codePointOffset} count as 456 * one code point each. 457 * 458 * @param index the index to be offset 459 * @param codePointOffset the offset in code points 460 * @return the index within this sequence 461 * @throws IndexOutOfBoundsException if {@code index} 462 * is negative or larger then the length of this sequence, 463 * or if {@code codePointOffset} is positive and the subsequence 464 * starting with {@code index} has fewer than 465 * {@code codePointOffset} code points, 466 * or if {@code codePointOffset} is negative and the subsequence 467 * before {@code index} has fewer than the absolute value of 468 * {@code codePointOffset} code points. 469 */ offsetByCodePoints(int index, int codePointOffset)470 public int offsetByCodePoints(int index, int codePointOffset) { 471 if (index < 0 || index > count) { 472 throw new IndexOutOfBoundsException(); 473 } 474 return Character.offsetByCodePoints(this, 475 index, codePointOffset); 476 } 477 478 /** 479 * Characters are copied from this sequence into the 480 * destination character array {@code dst}. The first character to 481 * be copied is at index {@code srcBegin}; the last character to 482 * be copied is at index {@code srcEnd-1}. The total number of 483 * characters to be copied is {@code srcEnd-srcBegin}. The 484 * characters are copied into the subarray of {@code dst} starting 485 * at index {@code dstBegin} and ending at index: 486 * <pre>{@code 487 * dstbegin + (srcEnd-srcBegin) - 1 488 * }</pre> 489 * 490 * @param srcBegin start copying at this offset. 491 * @param srcEnd stop copying at this offset. 492 * @param dst the array to copy the data into. 493 * @param dstBegin offset into {@code dst}. 494 * @throws IndexOutOfBoundsException if any of the following is true: 495 * <ul> 496 * <li>{@code srcBegin} is negative 497 * <li>{@code dstBegin} is negative 498 * <li>the {@code srcBegin} argument is greater than 499 * the {@code srcEnd} argument. 500 * <li>{@code srcEnd} is greater than 501 * {@code this.length()}. 502 * <li>{@code dstBegin+srcEnd-srcBegin} is greater than 503 * {@code dst.length} 504 * </ul> 505 */ getChars(int srcBegin, int srcEnd, char[] dst, int dstBegin)506 public void getChars(int srcBegin, int srcEnd, char[] dst, int dstBegin) 507 { 508 checkRangeSIOOBE(srcBegin, srcEnd, count); // compatible to old version 509 int n = srcEnd - srcBegin; 510 checkRange(dstBegin, dstBegin + n, dst.length); 511 if (isLatin1()) { 512 StringLatin1.getChars(value, srcBegin, srcEnd, dst, dstBegin); 513 } else { 514 StringUTF16.getChars(value, srcBegin, srcEnd, dst, dstBegin); 515 } 516 } 517 518 /** 519 * The character at the specified index is set to {@code ch}. This 520 * sequence is altered to represent a new character sequence that is 521 * identical to the old character sequence, except that it contains the 522 * character {@code ch} at position {@code index}. 523 * <p> 524 * The index argument must be greater than or equal to 525 * {@code 0}, and less than the length of this sequence. 526 * 527 * @param index the index of the character to modify. 528 * @param ch the new character. 529 * @throws IndexOutOfBoundsException if {@code index} is 530 * negative or greater than or equal to {@code length()}. 531 */ setCharAt(int index, char ch)532 public void setCharAt(int index, char ch) { 533 checkIndex(index, count); 534 if (isLatin1() && StringLatin1.canEncode(ch)) { 535 value[index] = (byte)ch; 536 } else { 537 if (isLatin1()) { 538 inflate(); 539 } 540 StringUTF16.putCharSB(value, index, ch); 541 } 542 } 543 544 /** 545 * Appends the string representation of the {@code Object} argument. 546 * <p> 547 * The overall effect is exactly as if the argument were converted 548 * to a string by the method {@link String#valueOf(Object)}, 549 * and the characters of that string were then 550 * {@link #append(String) appended} to this character sequence. 551 * 552 * @param obj an {@code Object}. 553 * @return a reference to this object. 554 */ append(Object obj)555 public AbstractStringBuilder append(Object obj) { 556 return append(String.valueOf(obj)); 557 } 558 559 /** 560 * Appends the specified string to this character sequence. 561 * <p> 562 * The characters of the {@code String} argument are appended, in 563 * order, increasing the length of this sequence by the length of the 564 * argument. If {@code str} is {@code null}, then the four 565 * characters {@code "null"} are appended. 566 * <p> 567 * Let <i>n</i> be the length of this character sequence just prior to 568 * execution of the {@code append} method. Then the character at 569 * index <i>k</i> in the new character sequence is equal to the character 570 * at index <i>k</i> in the old character sequence, if <i>k</i> is less 571 * than <i>n</i>; otherwise, it is equal to the character at index 572 * <i>k-n</i> in the argument {@code str}. 573 * 574 * @param str a string. 575 * @return a reference to this object. 576 */ append(String str)577 public AbstractStringBuilder append(String str) { 578 if (str == null) { 579 return appendNull(); 580 } 581 int len = str.length(); 582 ensureCapacityInternal(count + len); 583 putStringAt(count, str); 584 count += len; 585 return this; 586 } 587 588 /** 589 * Appends the specified {@code StringBuffer} to this sequence. 590 * 591 * @param sb the {@code StringBuffer} to append. 592 * @return a reference to this object. 593 */ append(StringBuffer sb)594 public AbstractStringBuilder append(StringBuffer sb) { 595 return this.append((AbstractStringBuilder)sb); 596 } 597 598 /** 599 * @since 1.8 600 */ append(AbstractStringBuilder asb)601 AbstractStringBuilder append(AbstractStringBuilder asb) { 602 if (asb == null) { 603 return appendNull(); 604 } 605 int len = asb.length(); 606 ensureCapacityInternal(count + len); 607 if (getCoder() != asb.getCoder()) { 608 inflate(); 609 } 610 asb.getBytes(value, count, coder); 611 count += len; 612 return this; 613 } 614 615 // Documentation in subclasses because of synchro difference 616 @Override append(CharSequence s)617 public AbstractStringBuilder append(CharSequence s) { 618 if (s == null) { 619 return appendNull(); 620 } 621 if (s instanceof String) { 622 return this.append((String)s); 623 } 624 if (s instanceof AbstractStringBuilder) { 625 return this.append((AbstractStringBuilder)s); 626 } 627 return this.append(s, 0, s.length()); 628 } 629 appendNull()630 private AbstractStringBuilder appendNull() { 631 ensureCapacityInternal(count + 4); 632 int count = this.count; 633 byte[] val = this.value; 634 if (isLatin1()) { 635 val[count++] = 'n'; 636 val[count++] = 'u'; 637 val[count++] = 'l'; 638 val[count++] = 'l'; 639 } else { 640 count = StringUTF16.putCharsAt(val, count, 'n', 'u', 'l', 'l'); 641 } 642 this.count = count; 643 return this; 644 } 645 646 /** 647 * Appends a subsequence of the specified {@code CharSequence} to this 648 * sequence. 649 * <p> 650 * Characters of the argument {@code s}, starting at 651 * index {@code start}, are appended, in order, to the contents of 652 * this sequence up to the (exclusive) index {@code end}. The length 653 * of this sequence is increased by the value of {@code end - start}. 654 * <p> 655 * Let <i>n</i> be the length of this character sequence just prior to 656 * execution of the {@code append} method. Then the character at 657 * index <i>k</i> in this character sequence becomes equal to the 658 * character at index <i>k</i> in this sequence, if <i>k</i> is less than 659 * <i>n</i>; otherwise, it is equal to the character at index 660 * <i>k+start-n</i> in the argument {@code s}. 661 * <p> 662 * If {@code s} is {@code null}, then this method appends 663 * characters as if the s parameter was a sequence containing the four 664 * characters {@code "null"}. 665 * 666 * @param s the sequence to append. 667 * @param start the starting index of the subsequence to be appended. 668 * @param end the end index of the subsequence to be appended. 669 * @return a reference to this object. 670 * @throws IndexOutOfBoundsException if 671 * {@code start} is negative, or 672 * {@code start} is greater than {@code end} or 673 * {@code end} is greater than {@code s.length()} 674 */ 675 @Override append(CharSequence s, int start, int end)676 public AbstractStringBuilder append(CharSequence s, int start, int end) { 677 if (s == null) { 678 s = "null"; 679 } 680 checkRange(start, end, s.length()); 681 int len = end - start; 682 ensureCapacityInternal(count + len); 683 if (s instanceof String) { 684 appendChars((String)s, start, end); 685 } else { 686 appendChars(s, start, end); 687 } 688 return this; 689 } 690 691 692 /** 693 * Appends the string representation of the {@code char} array 694 * argument to this sequence. 695 * <p> 696 * The characters of the array argument are appended, in order, to 697 * the contents of this sequence. The length of this sequence 698 * increases by the length of the argument. 699 * <p> 700 * The overall effect is exactly as if the argument were converted 701 * to a string by the method {@link String#valueOf(char[])}, 702 * and the characters of that string were then 703 * {@link #append(String) appended} to this character sequence. 704 * 705 * @param str the characters to be appended. 706 * @return a reference to this object. 707 */ append(char[] str)708 public AbstractStringBuilder append(char[] str) { 709 int len = str.length; 710 ensureCapacityInternal(count + len); 711 appendChars(str, 0, len); 712 return this; 713 } 714 715 /** 716 * Appends the string representation of a subarray of the 717 * {@code char} array argument to this sequence. 718 * <p> 719 * Characters of the {@code char} array {@code str}, starting at 720 * index {@code offset}, are appended, in order, to the contents 721 * of this sequence. The length of this sequence increases 722 * by the value of {@code len}. 723 * <p> 724 * The overall effect is exactly as if the arguments were converted 725 * to a string by the method {@link String#valueOf(char[],int,int)}, 726 * and the characters of that string were then 727 * {@link #append(String) appended} to this character sequence. 728 * 729 * @param str the characters to be appended. 730 * @param offset the index of the first {@code char} to append. 731 * @param len the number of {@code char}s to append. 732 * @return a reference to this object. 733 * @throws IndexOutOfBoundsException 734 * if {@code offset < 0} or {@code len < 0} 735 * or {@code offset+len > str.length} 736 */ append(char[] str, int offset, int len)737 public AbstractStringBuilder append(char[] str, int offset, int len) { 738 int end = offset + len; 739 checkRange(offset, end, str.length); 740 ensureCapacityInternal(count + len); 741 appendChars(str, offset, end); 742 return this; 743 } 744 745 /** 746 * Appends the string representation of the {@code boolean} 747 * argument to the sequence. 748 * <p> 749 * The overall effect is exactly as if the argument were converted 750 * to a string by the method {@link String#valueOf(boolean)}, 751 * and the characters of that string were then 752 * {@link #append(String) appended} to this character sequence. 753 * 754 * @param b a {@code boolean}. 755 * @return a reference to this object. 756 */ append(boolean b)757 public AbstractStringBuilder append(boolean b) { 758 ensureCapacityInternal(count + (b ? 4 : 5)); 759 int count = this.count; 760 byte[] val = this.value; 761 if (isLatin1()) { 762 if (b) { 763 val[count++] = 't'; 764 val[count++] = 'r'; 765 val[count++] = 'u'; 766 val[count++] = 'e'; 767 } else { 768 val[count++] = 'f'; 769 val[count++] = 'a'; 770 val[count++] = 'l'; 771 val[count++] = 's'; 772 val[count++] = 'e'; 773 } 774 } else { 775 if (b) { 776 count = StringUTF16.putCharsAt(val, count, 't', 'r', 'u', 'e'); 777 } else { 778 count = StringUTF16.putCharsAt(val, count, 'f', 'a', 'l', 's', 'e'); 779 } 780 } 781 this.count = count; 782 return this; 783 } 784 785 /** 786 * Appends the string representation of the {@code char} 787 * argument to this sequence. 788 * <p> 789 * The argument is appended to the contents of this sequence. 790 * The length of this sequence increases by {@code 1}. 791 * <p> 792 * The overall effect is exactly as if the argument were converted 793 * to a string by the method {@link String#valueOf(char)}, 794 * and the character in that string were then 795 * {@link #append(String) appended} to this character sequence. 796 * 797 * @param c a {@code char}. 798 * @return a reference to this object. 799 */ 800 @Override append(char c)801 public AbstractStringBuilder append(char c) { 802 ensureCapacityInternal(count + 1); 803 if (isLatin1() && StringLatin1.canEncode(c)) { 804 value[count++] = (byte)c; 805 } else { 806 if (isLatin1()) { 807 inflate(); 808 } 809 StringUTF16.putCharSB(value, count++, c); 810 } 811 return this; 812 } 813 814 /** 815 * Appends the string representation of the {@code int} 816 * argument to this sequence. 817 * <p> 818 * The overall effect is exactly as if the argument were converted 819 * to a string by the method {@link String#valueOf(int)}, 820 * and the characters of that string were then 821 * {@link #append(String) appended} to this character sequence. 822 * 823 * @param i an {@code int}. 824 * @return a reference to this object. 825 */ append(int i)826 public AbstractStringBuilder append(int i) { 827 int count = this.count; 828 int spaceNeeded = count + Integer.stringSize(i); 829 ensureCapacityInternal(spaceNeeded); 830 if (isLatin1()) { 831 Integer.getChars(i, spaceNeeded, value); 832 } else { 833 StringUTF16.getChars(i, count, spaceNeeded, value); 834 } 835 this.count = spaceNeeded; 836 return this; 837 } 838 839 /** 840 * Appends the string representation of the {@code long} 841 * argument to this sequence. 842 * <p> 843 * The overall effect is exactly as if the argument were converted 844 * to a string by the method {@link String#valueOf(long)}, 845 * and the characters of that string were then 846 * {@link #append(String) appended} to this character sequence. 847 * 848 * @param l a {@code long}. 849 * @return a reference to this object. 850 */ append(long l)851 public AbstractStringBuilder append(long l) { 852 int count = this.count; 853 int spaceNeeded = count + Long.stringSize(l); 854 ensureCapacityInternal(spaceNeeded); 855 if (isLatin1()) { 856 Long.getChars(l, spaceNeeded, value); 857 } else { 858 StringUTF16.getChars(l, count, spaceNeeded, value); 859 } 860 this.count = spaceNeeded; 861 return this; 862 } 863 864 /** 865 * Appends the string representation of the {@code float} 866 * argument to this sequence. 867 * <p> 868 * The overall effect is exactly as if the argument were converted 869 * to a string by the method {@link String#valueOf(float)}, 870 * and the characters of that string were then 871 * {@link #append(String) appended} to this character sequence. 872 * 873 * @param f a {@code float}. 874 * @return a reference to this object. 875 */ append(float f)876 public AbstractStringBuilder append(float f) { 877 FloatingDecimal.appendTo(f,this); 878 return this; 879 } 880 881 /** 882 * Appends the string representation of the {@code double} 883 * argument to this sequence. 884 * <p> 885 * The overall effect is exactly as if the argument were converted 886 * to a string by the method {@link String#valueOf(double)}, 887 * and the characters of that string were then 888 * {@link #append(String) appended} to this character sequence. 889 * 890 * @param d a {@code double}. 891 * @return a reference to this object. 892 */ append(double d)893 public AbstractStringBuilder append(double d) { 894 FloatingDecimal.appendTo(d,this); 895 return this; 896 } 897 898 /** 899 * Removes the characters in a substring of this sequence. 900 * The substring begins at the specified {@code start} and extends to 901 * the character at index {@code end - 1} or to the end of the 902 * sequence if no such character exists. If 903 * {@code start} is equal to {@code end}, no changes are made. 904 * 905 * @param start The beginning index, inclusive. 906 * @param end The ending index, exclusive. 907 * @return This object. 908 * @throws StringIndexOutOfBoundsException if {@code start} 909 * is negative, greater than {@code length()}, or 910 * greater than {@code end}. 911 */ delete(int start, int end)912 public AbstractStringBuilder delete(int start, int end) { 913 int count = this.count; 914 if (end > count) { 915 end = count; 916 } 917 checkRangeSIOOBE(start, end, count); 918 int len = end - start; 919 if (len > 0) { 920 shift(end, -len); 921 this.count = count - len; 922 } 923 return this; 924 } 925 926 /** 927 * Appends the string representation of the {@code codePoint} 928 * argument to this sequence. 929 * 930 * <p> The argument is appended to the contents of this sequence. 931 * The length of this sequence increases by 932 * {@link Character#charCount(int) Character.charCount(codePoint)}. 933 * 934 * <p> The overall effect is exactly as if the argument were 935 * converted to a {@code char} array by the method 936 * {@link Character#toChars(int)} and the character in that array 937 * were then {@link #append(char[]) appended} to this character 938 * sequence. 939 * 940 * @param codePoint a Unicode code point 941 * @return a reference to this object. 942 * @throws IllegalArgumentException if the specified 943 * {@code codePoint} isn't a valid Unicode code point 944 */ appendCodePoint(int codePoint)945 public AbstractStringBuilder appendCodePoint(int codePoint) { 946 if (Character.isBmpCodePoint(codePoint)) { 947 return append((char)codePoint); 948 } 949 return append(Character.toChars(codePoint)); 950 } 951 952 /** 953 * Removes the {@code char} at the specified position in this 954 * sequence. This sequence is shortened by one {@code char}. 955 * 956 * <p>Note: If the character at the given index is a supplementary 957 * character, this method does not remove the entire character. If 958 * correct handling of supplementary characters is required, 959 * determine the number of {@code char}s to remove by calling 960 * {@code Character.charCount(thisSequence.codePointAt(index))}, 961 * where {@code thisSequence} is this sequence. 962 * 963 * @param index Index of {@code char} to remove 964 * @return This object. 965 * @throws StringIndexOutOfBoundsException if the {@code index} 966 * is negative or greater than or equal to 967 * {@code length()}. 968 */ deleteCharAt(int index)969 public AbstractStringBuilder deleteCharAt(int index) { 970 checkIndex(index, count); 971 shift(index + 1, -1); 972 count--; 973 return this; 974 } 975 976 /** 977 * Replaces the characters in a substring of this sequence 978 * with characters in the specified {@code String}. The substring 979 * begins at the specified {@code start} and extends to the character 980 * at index {@code end - 1} or to the end of the 981 * sequence if no such character exists. First the 982 * characters in the substring are removed and then the specified 983 * {@code String} is inserted at {@code start}. (This 984 * sequence will be lengthened to accommodate the 985 * specified String if necessary.) 986 * 987 * @param start The beginning index, inclusive. 988 * @param end The ending index, exclusive. 989 * @param str String that will replace previous contents. 990 * @return This object. 991 * @throws StringIndexOutOfBoundsException if {@code start} 992 * is negative, greater than {@code length()}, or 993 * greater than {@code end}. 994 */ replace(int start, int end, String str)995 public AbstractStringBuilder replace(int start, int end, String str) { 996 int count = this.count; 997 if (end > count) { 998 end = count; 999 } 1000 checkRangeSIOOBE(start, end, count); 1001 int len = str.length(); 1002 int newCount = count + len - (end - start); 1003 ensureCapacityInternal(newCount); 1004 shift(end, newCount - count); 1005 this.count = newCount; 1006 putStringAt(start, str); 1007 return this; 1008 } 1009 1010 /** 1011 * Returns a new {@code String} that contains a subsequence of 1012 * characters currently contained in this character sequence. The 1013 * substring begins at the specified index and extends to the end of 1014 * this sequence. 1015 * 1016 * @param start The beginning index, inclusive. 1017 * @return The new string. 1018 * @throws StringIndexOutOfBoundsException if {@code start} is 1019 * less than zero, or greater than the length of this object. 1020 */ substring(int start)1021 public String substring(int start) { 1022 return substring(start, count); 1023 } 1024 1025 /** 1026 * Returns a new character sequence that is a subsequence of this sequence. 1027 * 1028 * <p> An invocation of this method of the form 1029 * 1030 * <pre>{@code 1031 * sb.subSequence(begin, end)}</pre> 1032 * 1033 * behaves in exactly the same way as the invocation 1034 * 1035 * <pre>{@code 1036 * sb.substring(begin, end)}</pre> 1037 * 1038 * This method is provided so that this class can 1039 * implement the {@link CharSequence} interface. 1040 * 1041 * @param start the start index, inclusive. 1042 * @param end the end index, exclusive. 1043 * @return the specified subsequence. 1044 * 1045 * @throws IndexOutOfBoundsException 1046 * if {@code start} or {@code end} are negative, 1047 * if {@code end} is greater than {@code length()}, 1048 * or if {@code start} is greater than {@code end} 1049 */ 1050 @Override subSequence(int start, int end)1051 public CharSequence subSequence(int start, int end) { 1052 return substring(start, end); 1053 } 1054 1055 /** 1056 * Returns a new {@code String} that contains a subsequence of 1057 * characters currently contained in this sequence. The 1058 * substring begins at the specified {@code start} and 1059 * extends to the character at index {@code end - 1}. 1060 * 1061 * @param start The beginning index, inclusive. 1062 * @param end The ending index, exclusive. 1063 * @return The new string. 1064 * @throws StringIndexOutOfBoundsException if {@code start} 1065 * or {@code end} are negative or greater than 1066 * {@code length()}, or {@code start} is 1067 * greater than {@code end}. 1068 */ substring(int start, int end)1069 public String substring(int start, int end) { 1070 checkRangeSIOOBE(start, end, count); 1071 if (isLatin1()) { 1072 return StringLatin1.newString(value, start, end - start); 1073 } 1074 return StringUTF16.newString(value, start, end - start); 1075 } 1076 shift(int offset, int n)1077 private void shift(int offset, int n) { 1078 System.arraycopy(value, offset << coder, 1079 value, (offset + n) << coder, (count - offset) << coder); 1080 } 1081 1082 /** 1083 * Inserts the string representation of a subarray of the {@code str} 1084 * array argument into this sequence. The subarray begins at the 1085 * specified {@code offset} and extends {@code len} {@code char}s. 1086 * The characters of the subarray are inserted into this sequence at 1087 * the position indicated by {@code index}. The length of this 1088 * sequence increases by {@code len} {@code char}s. 1089 * 1090 * @param index position at which to insert subarray. 1091 * @param str A {@code char} array. 1092 * @param offset the index of the first {@code char} in subarray to 1093 * be inserted. 1094 * @param len the number of {@code char}s in the subarray to 1095 * be inserted. 1096 * @return This object 1097 * @throws StringIndexOutOfBoundsException if {@code index} 1098 * is negative or greater than {@code length()}, or 1099 * {@code offset} or {@code len} are negative, or 1100 * {@code (offset+len)} is greater than 1101 * {@code str.length}. 1102 */ insert(int index, char[] str, int offset, int len)1103 public AbstractStringBuilder insert(int index, char[] str, int offset, 1104 int len) 1105 { 1106 checkOffset(index, count); 1107 checkRangeSIOOBE(offset, offset + len, str.length); 1108 ensureCapacityInternal(count + len); 1109 shift(index, len); 1110 count += len; 1111 putCharsAt(index, str, offset, offset + len); 1112 return this; 1113 } 1114 1115 /** 1116 * Inserts the string representation of the {@code Object} 1117 * argument into this character sequence. 1118 * <p> 1119 * The overall effect is exactly as if the second argument were 1120 * converted to a string by the method {@link String#valueOf(Object)}, 1121 * and the characters of that string were then 1122 * {@link #insert(int,String) inserted} into this character 1123 * sequence at the indicated offset. 1124 * <p> 1125 * The {@code offset} argument must be greater than or equal to 1126 * {@code 0}, and less than or equal to the {@linkplain #length() length} 1127 * of this sequence. 1128 * 1129 * @param offset the offset. 1130 * @param obj an {@code Object}. 1131 * @return a reference to this object. 1132 * @throws StringIndexOutOfBoundsException if the offset is invalid. 1133 */ insert(int offset, Object obj)1134 public AbstractStringBuilder insert(int offset, Object obj) { 1135 return insert(offset, String.valueOf(obj)); 1136 } 1137 1138 /** 1139 * Inserts the string into this character sequence. 1140 * <p> 1141 * The characters of the {@code String} argument are inserted, in 1142 * order, into this sequence at the indicated offset, moving up any 1143 * characters originally above that position and increasing the length 1144 * of this sequence by the length of the argument. If 1145 * {@code str} is {@code null}, then the four characters 1146 * {@code "null"} are inserted into this sequence. 1147 * <p> 1148 * The character at index <i>k</i> in the new character sequence is 1149 * equal to: 1150 * <ul> 1151 * <li>the character at index <i>k</i> in the old character sequence, if 1152 * <i>k</i> is less than {@code offset} 1153 * <li>the character at index <i>k</i>{@code -offset} in the 1154 * argument {@code str}, if <i>k</i> is not less than 1155 * {@code offset} but is less than {@code offset+str.length()} 1156 * <li>the character at index <i>k</i>{@code -str.length()} in the 1157 * old character sequence, if <i>k</i> is not less than 1158 * {@code offset+str.length()} 1159 * </ul><p> 1160 * The {@code offset} argument must be greater than or equal to 1161 * {@code 0}, and less than or equal to the {@linkplain #length() length} 1162 * of this sequence. 1163 * 1164 * @param offset the offset. 1165 * @param str a string. 1166 * @return a reference to this object. 1167 * @throws StringIndexOutOfBoundsException if the offset is invalid. 1168 */ insert(int offset, String str)1169 public AbstractStringBuilder insert(int offset, String str) { 1170 checkOffset(offset, count); 1171 if (str == null) { 1172 str = "null"; 1173 } 1174 int len = str.length(); 1175 ensureCapacityInternal(count + len); 1176 shift(offset, len); 1177 count += len; 1178 putStringAt(offset, str); 1179 return this; 1180 } 1181 1182 /** 1183 * Inserts the string representation of the {@code char} array 1184 * argument into this sequence. 1185 * <p> 1186 * The characters of the array argument are inserted into the 1187 * contents of this sequence at the position indicated by 1188 * {@code offset}. The length of this sequence increases by 1189 * the length of the argument. 1190 * <p> 1191 * The overall effect is exactly as if the second argument were 1192 * converted to a string by the method {@link String#valueOf(char[])}, 1193 * and the characters of that string were then 1194 * {@link #insert(int,String) inserted} into this character 1195 * sequence at the indicated offset. 1196 * <p> 1197 * The {@code offset} argument must be greater than or equal to 1198 * {@code 0}, and less than or equal to the {@linkplain #length() length} 1199 * of this sequence. 1200 * 1201 * @param offset the offset. 1202 * @param str a character array. 1203 * @return a reference to this object. 1204 * @throws StringIndexOutOfBoundsException if the offset is invalid. 1205 */ insert(int offset, char[] str)1206 public AbstractStringBuilder insert(int offset, char[] str) { 1207 checkOffset(offset, count); 1208 int len = str.length; 1209 ensureCapacityInternal(count + len); 1210 shift(offset, len); 1211 count += len; 1212 putCharsAt(offset, str, 0, len); 1213 return this; 1214 } 1215 1216 /** 1217 * Inserts the specified {@code CharSequence} into this sequence. 1218 * <p> 1219 * The characters of the {@code CharSequence} argument are inserted, 1220 * in order, into this sequence at the indicated offset, moving up 1221 * any characters originally above that position and increasing the length 1222 * of this sequence by the length of the argument s. 1223 * <p> 1224 * The result of this method is exactly the same as if it were an 1225 * invocation of this object's 1226 * {@link #insert(int,CharSequence,int,int) insert}(dstOffset, s, 0, s.length()) 1227 * method. 1228 * 1229 * <p>If {@code s} is {@code null}, then the four characters 1230 * {@code "null"} are inserted into this sequence. 1231 * 1232 * @param dstOffset the offset. 1233 * @param s the sequence to be inserted 1234 * @return a reference to this object. 1235 * @throws IndexOutOfBoundsException if the offset is invalid. 1236 */ insert(int dstOffset, CharSequence s)1237 public AbstractStringBuilder insert(int dstOffset, CharSequence s) { 1238 if (s == null) { 1239 s = "null"; 1240 } 1241 return this.insert(dstOffset, s, 0, s.length()); 1242 } 1243 1244 /** 1245 * Inserts a subsequence of the specified {@code CharSequence} into 1246 * this sequence. 1247 * <p> 1248 * The subsequence of the argument {@code s} specified by 1249 * {@code start} and {@code end} are inserted, 1250 * in order, into this sequence at the specified destination offset, moving 1251 * up any characters originally above that position. The length of this 1252 * sequence is increased by {@code end - start}. 1253 * <p> 1254 * The character at index <i>k</i> in this sequence becomes equal to: 1255 * <ul> 1256 * <li>the character at index <i>k</i> in this sequence, if 1257 * <i>k</i> is less than {@code dstOffset} 1258 * <li>the character at index <i>k</i>{@code +start-dstOffset} in 1259 * the argument {@code s}, if <i>k</i> is greater than or equal to 1260 * {@code dstOffset} but is less than {@code dstOffset+end-start} 1261 * <li>the character at index <i>k</i>{@code -(end-start)} in this 1262 * sequence, if <i>k</i> is greater than or equal to 1263 * {@code dstOffset+end-start} 1264 * </ul><p> 1265 * The {@code dstOffset} argument must be greater than or equal to 1266 * {@code 0}, and less than or equal to the {@linkplain #length() length} 1267 * of this sequence. 1268 * <p>The start argument must be nonnegative, and not greater than 1269 * {@code end}. 1270 * <p>The end argument must be greater than or equal to 1271 * {@code start}, and less than or equal to the length of s. 1272 * 1273 * <p>If {@code s} is {@code null}, then this method inserts 1274 * characters as if the s parameter was a sequence containing the four 1275 * characters {@code "null"}. 1276 * 1277 * @param dstOffset the offset in this sequence. 1278 * @param s the sequence to be inserted. 1279 * @param start the starting index of the subsequence to be inserted. 1280 * @param end the end index of the subsequence to be inserted. 1281 * @return a reference to this object. 1282 * @throws IndexOutOfBoundsException if {@code dstOffset} 1283 * is negative or greater than {@code this.length()}, or 1284 * {@code start} or {@code end} are negative, or 1285 * {@code start} is greater than {@code end} or 1286 * {@code end} is greater than {@code s.length()} 1287 */ insert(int dstOffset, CharSequence s, int start, int end)1288 public AbstractStringBuilder insert(int dstOffset, CharSequence s, 1289 int start, int end) 1290 { 1291 if (s == null) { 1292 s = "null"; 1293 } 1294 checkOffset(dstOffset, count); 1295 checkRange(start, end, s.length()); 1296 int len = end - start; 1297 ensureCapacityInternal(count + len); 1298 shift(dstOffset, len); 1299 count += len; 1300 if (s instanceof String) { 1301 putStringAt(dstOffset, (String) s, start, end); 1302 } else { 1303 putCharsAt(dstOffset, s, start, end); 1304 } 1305 return this; 1306 } 1307 1308 /** 1309 * Inserts the string representation of the {@code boolean} 1310 * argument into this sequence. 1311 * <p> 1312 * The overall effect is exactly as if the second argument were 1313 * converted to a string by the method {@link String#valueOf(boolean)}, 1314 * and the characters of that string were then 1315 * {@link #insert(int,String) inserted} into this character 1316 * sequence at the indicated offset. 1317 * <p> 1318 * The {@code offset} argument must be greater than or equal to 1319 * {@code 0}, and less than or equal to the {@linkplain #length() length} 1320 * of this sequence. 1321 * 1322 * @param offset the offset. 1323 * @param b a {@code boolean}. 1324 * @return a reference to this object. 1325 * @throws StringIndexOutOfBoundsException if the offset is invalid. 1326 */ insert(int offset, boolean b)1327 public AbstractStringBuilder insert(int offset, boolean b) { 1328 return insert(offset, String.valueOf(b)); 1329 } 1330 1331 /** 1332 * Inserts the string representation of the {@code char} 1333 * argument into this sequence. 1334 * <p> 1335 * The overall effect is exactly as if the second argument were 1336 * converted to a string by the method {@link String#valueOf(char)}, 1337 * and the character in that string were then 1338 * {@link #insert(int,String) inserted} into this character 1339 * sequence at the indicated offset. 1340 * <p> 1341 * The {@code offset} argument must be greater than or equal to 1342 * {@code 0}, and less than or equal to the {@linkplain #length() length} 1343 * of this sequence. 1344 * 1345 * @param offset the offset. 1346 * @param c a {@code char}. 1347 * @return a reference to this object. 1348 * @throws IndexOutOfBoundsException if the offset is invalid. 1349 */ insert(int offset, char c)1350 public AbstractStringBuilder insert(int offset, char c) { 1351 checkOffset(offset, count); 1352 ensureCapacityInternal(count + 1); 1353 shift(offset, 1); 1354 count += 1; 1355 if (isLatin1() && StringLatin1.canEncode(c)) { 1356 value[offset] = (byte)c; 1357 } else { 1358 if (isLatin1()) { 1359 inflate(); 1360 } 1361 StringUTF16.putCharSB(value, offset, c); 1362 } 1363 return this; 1364 } 1365 1366 /** 1367 * Inserts the string representation of the second {@code int} 1368 * argument into this sequence. 1369 * <p> 1370 * The overall effect is exactly as if the second argument were 1371 * converted to a string by the method {@link String#valueOf(int)}, 1372 * and the characters of that string were then 1373 * {@link #insert(int,String) inserted} into this character 1374 * sequence at the indicated offset. 1375 * <p> 1376 * The {@code offset} argument must be greater than or equal to 1377 * {@code 0}, and less than or equal to the {@linkplain #length() length} 1378 * of this sequence. 1379 * 1380 * @param offset the offset. 1381 * @param i an {@code int}. 1382 * @return a reference to this object. 1383 * @throws StringIndexOutOfBoundsException if the offset is invalid. 1384 */ insert(int offset, int i)1385 public AbstractStringBuilder insert(int offset, int i) { 1386 return insert(offset, String.valueOf(i)); 1387 } 1388 1389 /** 1390 * Inserts the string representation of the {@code long} 1391 * argument into this sequence. 1392 * <p> 1393 * The overall effect is exactly as if the second argument were 1394 * converted to a string by the method {@link String#valueOf(long)}, 1395 * and the characters of that string were then 1396 * {@link #insert(int,String) inserted} into this character 1397 * sequence at the indicated offset. 1398 * <p> 1399 * The {@code offset} argument must be greater than or equal to 1400 * {@code 0}, and less than or equal to the {@linkplain #length() length} 1401 * of this sequence. 1402 * 1403 * @param offset the offset. 1404 * @param l a {@code long}. 1405 * @return a reference to this object. 1406 * @throws StringIndexOutOfBoundsException if the offset is invalid. 1407 */ insert(int offset, long l)1408 public AbstractStringBuilder insert(int offset, long l) { 1409 return insert(offset, String.valueOf(l)); 1410 } 1411 1412 /** 1413 * Inserts the string representation of the {@code float} 1414 * argument into this sequence. 1415 * <p> 1416 * The overall effect is exactly as if the second argument were 1417 * converted to a string by the method {@link String#valueOf(float)}, 1418 * and the characters of that string were then 1419 * {@link #insert(int,String) inserted} into this character 1420 * sequence at the indicated offset. 1421 * <p> 1422 * The {@code offset} argument must be greater than or equal to 1423 * {@code 0}, and less than or equal to the {@linkplain #length() length} 1424 * of this sequence. 1425 * 1426 * @param offset the offset. 1427 * @param f a {@code float}. 1428 * @return a reference to this object. 1429 * @throws StringIndexOutOfBoundsException if the offset is invalid. 1430 */ insert(int offset, float f)1431 public AbstractStringBuilder insert(int offset, float f) { 1432 return insert(offset, String.valueOf(f)); 1433 } 1434 1435 /** 1436 * Inserts the string representation of the {@code double} 1437 * argument into this sequence. 1438 * <p> 1439 * The overall effect is exactly as if the second argument were 1440 * converted to a string by the method {@link String#valueOf(double)}, 1441 * and the characters of that string were then 1442 * {@link #insert(int,String) inserted} into this character 1443 * sequence at the indicated offset. 1444 * <p> 1445 * The {@code offset} argument must be greater than or equal to 1446 * {@code 0}, and less than or equal to the {@linkplain #length() length} 1447 * of this sequence. 1448 * 1449 * @param offset the offset. 1450 * @param d a {@code double}. 1451 * @return a reference to this object. 1452 * @throws StringIndexOutOfBoundsException if the offset is invalid. 1453 */ insert(int offset, double d)1454 public AbstractStringBuilder insert(int offset, double d) { 1455 return insert(offset, String.valueOf(d)); 1456 } 1457 1458 /** 1459 * Returns the index within this string of the first occurrence of the 1460 * specified substring. 1461 * 1462 * <p>The returned index is the smallest value {@code k} for which: 1463 * <pre>{@code 1464 * this.toString().startsWith(str, k) 1465 * }</pre> 1466 * If no such value of {@code k} exists, then {@code -1} is returned. 1467 * 1468 * @param str the substring to search for. 1469 * @return the index of the first occurrence of the specified substring, 1470 * or {@code -1} if there is no such occurrence. 1471 */ indexOf(String str)1472 public int indexOf(String str) { 1473 return indexOf(str, 0); 1474 } 1475 1476 /** 1477 * Returns the index within this string of the first occurrence of the 1478 * specified substring, starting at the specified index. 1479 * 1480 * <p>The returned index is the smallest value {@code k} for which: 1481 * <pre>{@code 1482 * k >= Math.min(fromIndex, this.length()) && 1483 * this.toString().startsWith(str, k) 1484 * }</pre> 1485 * If no such value of {@code k} exists, then {@code -1} is returned. 1486 * 1487 * @param str the substring to search for. 1488 * @param fromIndex the index from which to start the search. 1489 * @return the index of the first occurrence of the specified substring, 1490 * starting at the specified index, 1491 * or {@code -1} if there is no such occurrence. 1492 */ indexOf(String str, int fromIndex)1493 public int indexOf(String str, int fromIndex) { 1494 return String.indexOf(value, coder, count, str, fromIndex); 1495 } 1496 1497 /** 1498 * Returns the index within this string of the last occurrence of the 1499 * specified substring. The last occurrence of the empty string "" is 1500 * considered to occur at the index value {@code this.length()}. 1501 * 1502 * <p>The returned index is the largest value {@code k} for which: 1503 * <pre>{@code 1504 * this.toString().startsWith(str, k) 1505 * }</pre> 1506 * If no such value of {@code k} exists, then {@code -1} is returned. 1507 * 1508 * @param str the substring to search for. 1509 * @return the index of the last occurrence of the specified substring, 1510 * or {@code -1} if there is no such occurrence. 1511 */ lastIndexOf(String str)1512 public int lastIndexOf(String str) { 1513 return lastIndexOf(str, count); 1514 } 1515 1516 /** 1517 * Returns the index within this string of the last occurrence of the 1518 * specified substring, searching backward starting at the specified index. 1519 * 1520 * <p>The returned index is the largest value {@code k} for which: 1521 * <pre>{@code 1522 * k <= Math.min(fromIndex, this.length()) && 1523 * this.toString().startsWith(str, k) 1524 * }</pre> 1525 * If no such value of {@code k} exists, then {@code -1} is returned. 1526 * 1527 * @param str the substring to search for. 1528 * @param fromIndex the index to start the search from. 1529 * @return the index of the last occurrence of the specified substring, 1530 * searching backward from the specified index, 1531 * or {@code -1} if there is no such occurrence. 1532 */ lastIndexOf(String str, int fromIndex)1533 public int lastIndexOf(String str, int fromIndex) { 1534 return String.lastIndexOf(value, coder, count, str, fromIndex); 1535 } 1536 1537 /** 1538 * Causes this character sequence to be replaced by the reverse of 1539 * the sequence. If there are any surrogate pairs included in the 1540 * sequence, these are treated as single characters for the 1541 * reverse operation. Thus, the order of the high-low surrogates 1542 * is never reversed. 1543 * 1544 * Let <i>n</i> be the character length of this character sequence 1545 * (not the length in {@code char} values) just prior to 1546 * execution of the {@code reverse} method. Then the 1547 * character at index <i>k</i> in the new character sequence is 1548 * equal to the character at index <i>n-k-1</i> in the old 1549 * character sequence. 1550 * 1551 * <p>Note that the reverse operation may result in producing 1552 * surrogate pairs that were unpaired low-surrogates and 1553 * high-surrogates before the operation. For example, reversing 1554 * "\u005CuDC00\u005CuD800" produces "\u005CuD800\u005CuDC00" which is 1555 * a valid surrogate pair. 1556 * 1557 * @return a reference to this object. 1558 */ reverse()1559 public AbstractStringBuilder reverse() { 1560 byte[] val = this.value; 1561 int count = this.count; 1562 int n = count - 1; 1563 if (isLatin1()) { 1564 for (int j = (n-1) >> 1; j >= 0; j--) { 1565 int k = n - j; 1566 byte cj = val[j]; 1567 val[j] = val[k]; 1568 val[k] = cj; 1569 } 1570 } else { 1571 StringUTF16.reverse(val, count); 1572 } 1573 return this; 1574 } 1575 1576 /** 1577 * Returns a string representing the data in this sequence. 1578 * A new {@code String} object is allocated and initialized to 1579 * contain the character sequence currently represented by this 1580 * object. This {@code String} is then returned. Subsequent 1581 * changes to this sequence do not affect the contents of the 1582 * {@code String}. 1583 * 1584 * @return a string representation of this sequence of characters. 1585 */ 1586 @Override toString()1587 public abstract String toString(); 1588 1589 /** 1590 * {@inheritDoc} 1591 * @since 9 1592 */ 1593 @Override chars()1594 public IntStream chars() { 1595 // Reuse String-based spliterator. This requires a supplier to 1596 // capture the value and count when the terminal operation is executed 1597 return StreamSupport.intStream( 1598 () -> { 1599 // The combined set of field reads are not atomic and thread 1600 // safe but bounds checks will ensure no unsafe reads from 1601 // the byte array 1602 byte[] val = this.value; 1603 int count = this.count; 1604 byte coder = this.coder; 1605 return coder == LATIN1 1606 ? new StringLatin1.CharsSpliterator(val, 0, count, 0) 1607 : new StringUTF16.CharsSpliterator(val, 0, count, 0); 1608 }, 1609 Spliterator.ORDERED | Spliterator.SIZED | Spliterator.SUBSIZED, 1610 false); 1611 } 1612 1613 /** 1614 * {@inheritDoc} 1615 * @since 9 1616 */ 1617 @Override codePoints()1618 public IntStream codePoints() { 1619 // Reuse String-based spliterator. This requires a supplier to 1620 // capture the value and count when the terminal operation is executed 1621 return StreamSupport.intStream( 1622 () -> { 1623 // The combined set of field reads are not atomic and thread 1624 // safe but bounds checks will ensure no unsafe reads from 1625 // the byte array 1626 byte[] val = this.value; 1627 int count = this.count; 1628 byte coder = this.coder; 1629 return coder == LATIN1 1630 ? new StringLatin1.CharsSpliterator(val, 0, count, 0) 1631 : new StringUTF16.CodePointsSpliterator(val, 0, count, 0); 1632 }, 1633 Spliterator.ORDERED, 1634 false); 1635 } 1636 1637 /** 1638 * Needed by {@code String} for the contentEquals method. 1639 */ 1640 final byte[] getValue() { 1641 return value; 1642 } 1643 1644 /* 1645 * Invoker guarantees it is in UTF16 (inflate itself for asb), if two 1646 * coders are different and the dstBegin has enough space 1647 * 1648 * @param dstBegin the char index, not offset of byte[] 1649 * @param coder the coder of dst[] 1650 */ 1651 void getBytes(byte[] dst, int dstBegin, byte coder) { 1652 if (this.coder == coder) { 1653 System.arraycopy(value, 0, dst, dstBegin << coder, count << coder); 1654 } else { // this.coder == LATIN && coder == UTF16 1655 StringLatin1.inflate(value, 0, dst, dstBegin, count); 1656 } 1657 } 1658 1659 /* for readObject() */ 1660 void initBytes(char[] value, int off, int len) { 1661 if (String.COMPACT_STRINGS) { 1662 this.value = StringUTF16.compress(value, off, len); 1663 if (this.value != null) { 1664 this.coder = LATIN1; 1665 return; 1666 } 1667 } 1668 this.coder = UTF16; 1669 this.value = StringUTF16.toBytes(value, off, len); 1670 } 1671 1672 final byte getCoder() { 1673 return COMPACT_STRINGS ? coder : UTF16; 1674 } 1675 1676 final boolean isLatin1() { 1677 return COMPACT_STRINGS && coder == LATIN1; 1678 } 1679 1680 private final void putCharsAt(int index, char[] s, int off, int end) { 1681 if (isLatin1()) { 1682 byte[] val = this.value; 1683 for (int i = off, j = index; i < end; i++) { 1684 char c = s[i]; 1685 if (StringLatin1.canEncode(c)) { 1686 val[j++] = (byte)c; 1687 } else { 1688 inflate(); 1689 StringUTF16.putCharsSB(this.value, j, s, i, end); 1690 return; 1691 } 1692 } 1693 } else { 1694 StringUTF16.putCharsSB(this.value, index, s, off, end); 1695 } 1696 } 1697 1698 private final void putCharsAt(int index, CharSequence s, int off, int end) { 1699 if (isLatin1()) { 1700 byte[] val = this.value; 1701 for (int i = off, j = index; i < end; i++) { 1702 char c = s.charAt(i); 1703 if (StringLatin1.canEncode(c)) { 1704 val[j++] = (byte)c; 1705 } else { 1706 inflate(); 1707 StringUTF16.putCharsSB(this.value, j, s, i, end); 1708 return; 1709 } 1710 } 1711 } else { 1712 StringUTF16.putCharsSB(this.value, index, s, off, end); 1713 } 1714 } 1715 1716 private void putStringAt(int index, String str, int off, int end) { 1717 if (getCoder() != str.coder()) { 1718 inflate(); 1719 } 1720 str.getBytes(value, off, index, coder, end - off); 1721 } 1722 1723 private void putStringAt(int index, String str) { 1724 putStringAt(index, str, 0, str.length()); 1725 } 1726 1727 private final void appendChars(char[] s, int off, int end) { 1728 int count = this.count; 1729 if (isLatin1()) { 1730 byte[] val = this.value; 1731 for (int i = off, j = count; i < end; i++) { 1732 char c = s[i]; 1733 if (StringLatin1.canEncode(c)) { 1734 val[j++] = (byte)c; 1735 } else { 1736 this.count = count = j; 1737 inflate(); 1738 StringUTF16.putCharsSB(this.value, j, s, i, end); 1739 this.count = count + end - i; 1740 return; 1741 } 1742 } 1743 } else { 1744 StringUTF16.putCharsSB(this.value, count, s, off, end); 1745 } 1746 this.count = count + end - off; 1747 } 1748 1749 private final void appendChars(String s, int off, int end) { 1750 if (isLatin1()) { 1751 if (s.isLatin1()) { 1752 System.arraycopy(s.value(), off, this.value, this.count, end - off); 1753 } else { 1754 // We might need to inflate, but do it as late as possible since 1755 // the range of characters we're copying might all be latin1 1756 byte[] val = this.value; 1757 for (int i = off, j = count; i < end; i++) { 1758 char c = s.charAt(i); 1759 if (StringLatin1.canEncode(c)) { 1760 val[j++] = (byte) c; 1761 } else { 1762 count = j; 1763 inflate(); 1764 System.arraycopy(s.value(), i << UTF16, this.value, j << UTF16, (end - i) << UTF16); 1765 count += end - i; 1766 return; 1767 } 1768 } 1769 } 1770 } else if (s.isLatin1()) { 1771 StringUTF16.putCharsSB(this.value, this.count, s, off, end); 1772 } else { // both UTF16 1773 System.arraycopy(s.value(), off << UTF16, this.value, this.count << UTF16, (end - off) << UTF16); 1774 } 1775 count += end - off; 1776 } 1777 1778 private final void appendChars(CharSequence s, int off, int end) { 1779 if (isLatin1()) { 1780 byte[] val = this.value; 1781 for (int i = off, j = count; i < end; i++) { 1782 char c = s.charAt(i); 1783 if (StringLatin1.canEncode(c)) { 1784 val[j++] = (byte)c; 1785 } else { 1786 count = j; 1787 inflate(); 1788 StringUTF16.putCharsSB(this.value, j, s, i, end); 1789 count += end - i; 1790 return; 1791 } 1792 } 1793 } else { 1794 StringUTF16.putCharsSB(this.value, count, s, off, end); 1795 } 1796 count += end - off; 1797 } 1798 1799 /* IndexOutOfBoundsException, if out of bounds */ 1800 private static void checkRange(int start, int end, int len) { 1801 if (start < 0 || start > end || end > len) { 1802 throw new IndexOutOfBoundsException( 1803 "start " + start + ", end " + end + ", length " + len); 1804 } 1805 } 1806 1807 /* StringIndexOutOfBoundsException, if out of bounds */ 1808 private static void checkRangeSIOOBE(int start, int end, int len) { 1809 if (start < 0 || start > end || end > len) { 1810 throw new StringIndexOutOfBoundsException( 1811 "start " + start + ", end " + end + ", length " + len); 1812 } 1813 } 1814 } 1815