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
26 package java.lang;
27
28 import jdk.internal.math.FloatingDecimal;
29 import java.util.Arrays;
30 import java.util.Spliterator;
31 import java.util.stream.IntStream;
32 import java.util.stream.StreamSupport;
33
34 import static java.lang.String.COMPACT_STRINGS;
35 import static java.lang.String.UTF16;
36 import static java.lang.String.LATIN1;
37 import static java.lang.String.checkIndex;
38 import 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 */
56 abstract 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 }