1 /*
2 * Copyright (c) 2003, 2016, 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 checkIndex(index, count);
311 if (isLatin1()) {
312 return value[index] & 0xff;
313 }
314 return StringUTF16.codePointAtSB(value, index, count);
315 }
316
317 /**
318 * Returns the character (Unicode code point) before the specified
319 * index. The index refers to {@code char} values
320 * (Unicode code units) and ranges from {@code 1} to {@link
321 * #length()}.
322 *
323 * <p> If the {@code char} value at {@code (index - 1)}
324 * is in the low-surrogate range, {@code (index - 2)} is not
325 * negative, and the {@code char} value at {@code (index -
326 * 2)} is in the high-surrogate range, then the
327 * supplementary code point value of the surrogate pair is
328 * returned. If the {@code char} value at {@code index -
329 * 1} is an unpaired low-surrogate or a high-surrogate, the
330 * surrogate value is returned.
331 *
332 * @param index the index following the code point that should be returned
333 * @return the Unicode code point value before the given index.
334 * @exception IndexOutOfBoundsException if the {@code index}
335 * argument is less than 1 or greater than the length
336 * of this sequence.
337 */
338 public int codePointBefore(int index) {
339 int i = index - 1;
340 if (i < 0 || i >= count) {
341 throw new StringIndexOutOfBoundsException(index);
342 }
343 if (isLatin1()) {
344 return value[i] & 0xff;
345 }
346 return StringUTF16.codePointBeforeSB(value, index);
347 }
348
349 /**
350 * Returns the number of Unicode code points in the specified text
351 * range of this sequence. The text range begins at the specified
352 * {@code beginIndex} and extends to the {@code char} at
353 * index {@code endIndex - 1}. Thus the length (in
354 * {@code char}s) of the text range is
355 * {@code endIndex-beginIndex}. Unpaired surrogates within
356 * this sequence count as one code point each.
357 *
358 * @param beginIndex the index to the first {@code char} of
359 * the text range.
360 * @param endIndex the index after the last {@code char} of
361 * the text range.
362 * @return the number of Unicode code points in the specified text
363 * range
364 * @exception IndexOutOfBoundsException if the
365 * {@code beginIndex} is negative, or {@code endIndex}
366 * is larger than the length of this sequence, or
367 * {@code beginIndex} is larger than {@code endIndex}.
368 */
369 public int codePointCount(int beginIndex, int endIndex) {
370 if (beginIndex < 0 || endIndex > count || beginIndex > endIndex) {
371 throw new IndexOutOfBoundsException();
372 }
373 if (isLatin1()) {
374 return endIndex - beginIndex;
375 }
376 return StringUTF16.codePointCountSB(value, beginIndex, endIndex);
377 }
378
379 /**
380 * Returns the index within this sequence that is offset from the
381 * given {@code index} by {@code codePointOffset} code
382 * points. Unpaired surrogates within the text range given by
383 * {@code index} and {@code codePointOffset} count as
384 * one code point each.
385 *
386 * @param index the index to be offset
387 * @param codePointOffset the offset in code points
388 * @return the index within this sequence
389 * @exception IndexOutOfBoundsException if {@code index}
390 * is negative or larger then the length of this sequence,
391 * or if {@code codePointOffset} is positive and the subsequence
392 * starting with {@code index} has fewer than
393 * {@code codePointOffset} code points,
394 * or if {@code codePointOffset} is negative and the subsequence
395 * before {@code index} has fewer than the absolute value of
396 * {@code codePointOffset} code points.
397 */
398 public int offsetByCodePoints(int index, int codePointOffset) {
399 if (index < 0 || index > count) {
400 throw new IndexOutOfBoundsException();
401 }
402 return Character.offsetByCodePoints(this,
403 index, codePointOffset);
404 }
405
406 /**
407 * Characters are copied from this sequence into the
408 * destination character array {@code dst}. The first character to
409 * be copied is at index {@code srcBegin}; the last character to
410 * be copied is at index {@code srcEnd-1}. The total number of
411 * characters to be copied is {@code srcEnd-srcBegin}. The
412 * characters are copied into the subarray of {@code dst} starting
413 * at index {@code dstBegin} and ending at index:
414 * <pre>{@code
415 * dstbegin + (srcEnd-srcBegin) - 1
416 * }</pre>
417 *
418 * @param srcBegin start copying at this offset.
419 * @param srcEnd stop copying at this offset.
420 * @param dst the array to copy the data into.
421 * @param dstBegin offset into {@code dst}.
422 * @throws IndexOutOfBoundsException if any of the following is true:
423 * <ul>
424 * <li>{@code srcBegin} is negative
425 * <li>{@code dstBegin} is negative
426 * <li>the {@code srcBegin} argument is greater than
427 * the {@code srcEnd} argument.
428 * <li>{@code srcEnd} is greater than
429 * {@code this.length()}.
430 * <li>{@code dstBegin+srcEnd-srcBegin} is greater than
431 * {@code dst.length}
432 * </ul>
433 */
434 public void getChars(int srcBegin, int srcEnd, char[] dst, int dstBegin)
435 {
436 checkRangeSIOOBE(srcBegin, srcEnd, count); // compatible to old version
437 int n = srcEnd - srcBegin;
438 checkRange(dstBegin, dstBegin + n, dst.length);
439 if (isLatin1()) {
440 StringLatin1.getChars(value, srcBegin, srcEnd, dst, dstBegin);
441 } else {
442 StringUTF16.getChars(value, srcBegin, srcEnd, dst, dstBegin);
443 }
444 }
445
446 /**
447 * The character at the specified index is set to {@code ch}. This
448 * sequence is altered to represent a new character sequence that is
449 * identical to the old character sequence, except that it contains the
450 * character {@code ch} at position {@code index}.
451 * <p>
452 * The index argument must be greater than or equal to
453 * {@code 0}, and less than the length of this sequence.
454 *
455 * @param index the index of the character to modify.
456 * @param ch the new character.
457 * @throws IndexOutOfBoundsException if {@code index} is
458 * negative or greater than or equal to {@code length()}.
459 */
460 public void setCharAt(int index, char ch) {
461 checkIndex(index, count);
462 if (isLatin1() && StringLatin1.canEncode(ch)) {
463 value[index] = (byte)ch;
464 } else {
465 if (isLatin1()) {
466 inflate();
467 }
468 StringUTF16.putCharSB(value, index, ch);
469 }
470 }
471
472 /**
473 * Appends the string representation of the {@code Object} argument.
474 * <p>
475 * The overall effect is exactly as if the argument were converted
476 * to a string by the method {@link String#valueOf(Object)},
477 * and the characters of that string were then
478 * {@link #append(String) appended} to this character sequence.
479 *
480 * @param obj an {@code Object}.
481 * @return a reference to this object.
482 */
483 public AbstractStringBuilder append(Object obj) {
484 return append(String.valueOf(obj));
485 }
486
487 /**
488 * Appends the specified string to this character sequence.
489 * <p>
490 * The characters of the {@code String} argument are appended, in
491 * order, increasing the length of this sequence by the length of the
492 * argument. If {@code str} is {@code null}, then the four
493 * characters {@code "null"} are appended.
494 * <p>
495 * Let <i>n</i> be the length of this character sequence just prior to
496 * execution of the {@code append} method. Then the character at
497 * index <i>k</i> in the new character sequence is equal to the character
498 * at index <i>k</i> in the old character sequence, if <i>k</i> is less
499 * than <i>n</i>; otherwise, it is equal to the character at index
500 * <i>k-n</i> in the argument {@code str}.
501 *
502 * @param str a string.
503 * @return a reference to this object.
504 */
505 public AbstractStringBuilder append(String str) {
506 if (str == null) {
507 return appendNull();
508 }
509 int len = str.length();
510 ensureCapacityInternal(count + len);
511 putStringAt(count, str);
512 count += len;
513 return this;
514 }
515
516 // Documentation in subclasses because of synchro difference
517 public AbstractStringBuilder append(StringBuffer sb) {
518 return this.append((AbstractStringBuilder)sb);
519 }
520
521 /**
522 * @since 1.8
523 */
524 AbstractStringBuilder append(AbstractStringBuilder asb) {
525 if (asb == null) {
526 return appendNull();
527 }
528 int len = asb.length();
529 ensureCapacityInternal(count + len);
530 if (getCoder() != asb.getCoder()) {
531 inflate();
532 }
533 asb.getBytes(value, count, coder);
534 count += len;
535 return this;
536 }
537
538 // Documentation in subclasses because of synchro difference
539 @Override
540 public AbstractStringBuilder append(CharSequence s) {
541 if (s == null) {
542 return appendNull();
543 }
544 if (s instanceof String) {
545 return this.append((String)s);
546 }
547 if (s instanceof AbstractStringBuilder) {
548 return this.append((AbstractStringBuilder)s);
549 }
550 return this.append(s, 0, s.length());
551 }
552
553 private AbstractStringBuilder appendNull() {
554 ensureCapacityInternal(count + 4);
555 int count = this.count;
556 byte[] val = this.value;
557 if (isLatin1()) {
558 val[count++] = 'n';
559 val[count++] = 'u';
560 val[count++] = 'l';
561 val[count++] = 'l';
562 } else {
563 checkOffset(count + 4, val.length >> 1);
564 StringUTF16.putChar(val, count++, 'n');
565 StringUTF16.putChar(val, count++, 'u');
566 StringUTF16.putChar(val, count++, 'l');
567 StringUTF16.putChar(val, count++, 'l');
568 }
569 this.count = count;
570 return this;
571 }
572
573 /**
574 * Appends a subsequence of the specified {@code CharSequence} to this
575 * sequence.
576 * <p>
577 * Characters of the argument {@code s}, starting at
578 * index {@code start}, are appended, in order, to the contents of
579 * this sequence up to the (exclusive) index {@code end}. The length
580 * of this sequence is increased by the value of {@code end - start}.
581 * <p>
582 * Let <i>n</i> be the length of this character sequence just prior to
583 * execution of the {@code append} method. Then the character at
584 * index <i>k</i> in this character sequence becomes equal to the
585 * character at index <i>k</i> in this sequence, if <i>k</i> is less than
586 * <i>n</i>; otherwise, it is equal to the character at index
587 * <i>k+start-n</i> in the argument {@code s}.
588 * <p>
589 * If {@code s} is {@code null}, then this method appends
590 * characters as if the s parameter was a sequence containing the four
591 * characters {@code "null"}.
592 *
593 * @param s the sequence to append.
594 * @param start the starting index of the subsequence to be appended.
595 * @param end the end index of the subsequence to be appended.
596 * @return a reference to this object.
597 * @throws IndexOutOfBoundsException if
598 * {@code start} is negative, or
599 * {@code start} is greater than {@code end} or
600 * {@code end} is greater than {@code s.length()}
601 */
602 @Override
603 public AbstractStringBuilder append(CharSequence s, int start, int end) {
604 if (s == null) {
605 s = "null";
606 }
607 checkRange(start, end, s.length());
608 int len = end - start;
609 ensureCapacityInternal(count + len);
610 appendChars(s, start, end);
611 return this;
612 }
613
614 /**
615 * Appends the string representation of the {@code char} array
616 * argument to this sequence.
617 * <p>
618 * The characters of the array argument are appended, in order, to
619 * the contents of this sequence. The length of this sequence
620 * increases by the length of the argument.
621 * <p>
622 * The overall effect is exactly as if the argument were converted
623 * to a string by the method {@link String#valueOf(char[])},
624 * and the characters of that string were then
625 * {@link #append(String) appended} to this character sequence.
626 *
627 * @param str the characters to be appended.
628 * @return a reference to this object.
629 */
630 public AbstractStringBuilder append(char[] str) {
631 int len = str.length;
632 ensureCapacityInternal(count + len);
633 appendChars(str, 0, len);
634 return this;
635 }
636
637 /**
638 * Appends the string representation of a subarray of the
639 * {@code char} array argument to this sequence.
640 * <p>
641 * Characters of the {@code char} array {@code str}, starting at
642 * index {@code offset}, are appended, in order, to the contents
643 * of this sequence. The length of this sequence increases
644 * by the value of {@code len}.
645 * <p>
646 * The overall effect is exactly as if the arguments were converted
647 * to a string by the method {@link String#valueOf(char[],int,int)},
648 * and the characters of that string were then
649 * {@link #append(String) appended} to this character sequence.
650 *
651 * @param str the characters to be appended.
652 * @param offset the index of the first {@code char} to append.
653 * @param len the number of {@code char}s to append.
654 * @return a reference to this object.
655 * @throws IndexOutOfBoundsException
656 * if {@code offset < 0} or {@code len < 0}
657 * or {@code offset+len > str.length}
658 */
659 public AbstractStringBuilder append(char str[], int offset, int len) {
660 int end = offset + len;
661 checkRange(offset, end, str.length);
662 ensureCapacityInternal(count + len);
663 appendChars(str, offset, end);
664 return this;
665 }
666
667 /**
668 * Appends the string representation of the {@code boolean}
669 * argument to the sequence.
670 * <p>
671 * The overall effect is exactly as if the argument were converted
672 * to a string by the method {@link String#valueOf(boolean)},
673 * and the characters of that string were then
674 * {@link #append(String) appended} to this character sequence.
675 *
676 * @param b a {@code boolean}.
677 * @return a reference to this object.
678 */
679 public AbstractStringBuilder append(boolean b) {
680 ensureCapacityInternal(count + (b ? 4 : 5));
681 int count = this.count;
682 byte[] val = this.value;
683 if (isLatin1()) {
684 if (b) {
685 val[count++] = 't';
686 val[count++] = 'r';
687 val[count++] = 'u';
688 val[count++] = 'e';
689 } else {
690 val[count++] = 'f';
691 val[count++] = 'a';
692 val[count++] = 'l';
693 val[count++] = 's';
694 val[count++] = 'e';
695 }
696 } else {
697 if (b) {
698 checkOffset(count + 4, val.length >> 1);
699 StringUTF16.putChar(val, count++, 't');
700 StringUTF16.putChar(val, count++, 'r');
701 StringUTF16.putChar(val, count++, 'u');
702 StringUTF16.putChar(val, count++, 'e');
703 } else {
704 checkOffset(count + 5, val.length >> 1);
705 StringUTF16.putChar(val, count++, 'f');
706 StringUTF16.putChar(val, count++, 'a');
707 StringUTF16.putChar(val, count++, 'l');
708 StringUTF16.putChar(val, count++, 's');
709 StringUTF16.putChar(val, count++, 'e');
710 }
711 }
712 this.count = count;
713 return this;
714 }
715
716 /**
717 * Appends the string representation of the {@code char}
718 * argument to this sequence.
719 * <p>
720 * The argument is appended to the contents of this sequence.
721 * The length of this sequence increases by {@code 1}.
722 * <p>
723 * The overall effect is exactly as if the argument were converted
724 * to a string by the method {@link String#valueOf(char)},
725 * and the character in that string were then
726 * {@link #append(String) appended} to this character sequence.
727 *
728 * @param c a {@code char}.
729 * @return a reference to this object.
730 */
731 @Override
732 public AbstractStringBuilder append(char c) {
733 ensureCapacityInternal(count + 1);
734 if (isLatin1() && StringLatin1.canEncode(c)) {
735 value[count++] = (byte)c;
736 } else {
737 if (isLatin1()) {
738 inflate();
739 }
740 StringUTF16.putCharSB(value, count++, c);
741 }
742 return this;
743 }
744
745 /**
746 * Appends the string representation of the {@code int}
747 * argument to this 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(int)},
751 * and the characters of that string were then
752 * {@link #append(String) appended} to this character sequence.
753 *
754 * @param i an {@code int}.
755 * @return a reference to this object.
756 */
757 public AbstractStringBuilder append(int i) {
758 int spaceNeeded = count + Integer.stringSize(i);
759 ensureCapacityInternal(spaceNeeded);
760 if (isLatin1()) {
761 Integer.getChars(i, spaceNeeded, value);
762 } else {
763 byte[] val = this.value;
764 checkOffset(spaceNeeded, val.length >> 1);
765 Integer.getCharsUTF16(i, spaceNeeded, val);
766 }
767 count = spaceNeeded;
768 return this;
769 }
770
771 /**
772 * Appends the string representation of the {@code long}
773 * argument to this sequence.
774 * <p>
775 * The overall effect is exactly as if the argument were converted
776 * to a string by the method {@link String#valueOf(long)},
777 * and the characters of that string were then
778 * {@link #append(String) appended} to this character sequence.
779 *
780 * @param l a {@code long}.
781 * @return a reference to this object.
782 */
783 public AbstractStringBuilder append(long l) {
784 int spaceNeeded = count + Long.stringSize(l);
785 ensureCapacityInternal(spaceNeeded);
786 if (isLatin1()) {
787 Long.getChars(l, spaceNeeded, value);
788 } else {
789 byte[] val = this.value;
790 checkOffset(spaceNeeded, val.length >> 1);
791 Long.getCharsUTF16(l, spaceNeeded, val);
792 }
793 count = spaceNeeded;
794 return this;
795 }
796
797 /**
798 * Appends the string representation of the {@code float}
799 * argument to this sequence.
800 * <p>
801 * The overall effect is exactly as if the argument were converted
802 * to a string by the method {@link String#valueOf(float)},
803 * and the characters of that string were then
804 * {@link #append(String) appended} to this character sequence.
805 *
806 * @param f a {@code float}.
807 * @return a reference to this object.
808 */
809 public AbstractStringBuilder append(float f) {
810 FloatingDecimal.appendTo(f,this);
811 return this;
812 }
813
814 /**
815 * Appends the string representation of the {@code double}
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(double)},
820 * and the characters of that string were then
821 * {@link #append(String) appended} to this character sequence.
822 *
823 * @param d a {@code double}.
824 * @return a reference to this object.
825 */
826 public AbstractStringBuilder append(double d) {
827 FloatingDecimal.appendTo(d,this);
828 return this;
829 }
830
831 /**
832 * Removes the characters in a substring of this sequence.
833 * The substring begins at the specified {@code start} and extends to
834 * the character at index {@code end - 1} or to the end of the
835 * sequence if no such character exists. If
836 * {@code start} is equal to {@code end}, no changes are made.
837 *
838 * @param start The beginning index, inclusive.
839 * @param end The ending index, exclusive.
840 * @return This object.
841 * @throws StringIndexOutOfBoundsException if {@code start}
842 * is negative, greater than {@code length()}, or
843 * greater than {@code end}.
844 */
845 public AbstractStringBuilder delete(int start, int end) {
846 if (end > count) {
847 end = count;
848 }
849 checkRangeSIOOBE(start, end, count);
850 int len = end - start;
851 if (len > 0) {
852 shift(end, -len);
853 count -= len;
854 }
855 return this;
856 }
857
858 /**
859 * Appends the string representation of the {@code codePoint}
860 * argument to this sequence.
861 *
862 * <p> The argument is appended to the contents of this sequence.
863 * The length of this sequence increases by
864 * {@link Character#charCount(int) Character.charCount(codePoint)}.
865 *
866 * <p> The overall effect is exactly as if the argument were
867 * converted to a {@code char} array by the method
868 * {@link Character#toChars(int)} and the character in that array
869 * were then {@link #append(char[]) appended} to this character
870 * sequence.
871 *
872 * @param codePoint a Unicode code point
873 * @return a reference to this object.
874 * @exception IllegalArgumentException if the specified
875 * {@code codePoint} isn't a valid Unicode code point
876 */
877 public AbstractStringBuilder appendCodePoint(int codePoint) {
878 if (Character.isBmpCodePoint(codePoint)) {
879 return append((char)codePoint);
880 }
881 return append(Character.toChars(codePoint));
882 }
883
884 /**
885 * Removes the {@code char} at the specified position in this
886 * sequence. This sequence is shortened by one {@code char}.
887 *
888 * <p>Note: If the character at the given index is a supplementary
889 * character, this method does not remove the entire character. If
890 * correct handling of supplementary characters is required,
891 * determine the number of {@code char}s to remove by calling
892 * {@code Character.charCount(thisSequence.codePointAt(index))},
893 * where {@code thisSequence} is this sequence.
894 *
895 * @param index Index of {@code char} to remove
896 * @return This object.
897 * @throws StringIndexOutOfBoundsException if the {@code index}
898 * is negative or greater than or equal to
899 * {@code length()}.
900 */
901 public AbstractStringBuilder deleteCharAt(int index) {
902 checkIndex(index, count);
903 shift(index + 1, -1);
904 count--;
905 return this;
906 }
907
908 /**
909 * Replaces the characters in a substring of this sequence
910 * with characters in the specified {@code String}. The substring
911 * begins at the specified {@code start} and extends to the character
912 * at index {@code end - 1} or to the end of the
913 * sequence if no such character exists. First the
914 * characters in the substring are removed and then the specified
915 * {@code String} is inserted at {@code start}. (This
916 * sequence will be lengthened to accommodate the
917 * specified String if necessary.)
918 *
919 * @param start The beginning index, inclusive.
920 * @param end The ending index, exclusive.
921 * @param str String that will replace previous contents.
922 * @return This object.
923 * @throws StringIndexOutOfBoundsException if {@code start}
924 * is negative, greater than {@code length()}, or
925 * greater than {@code end}.
926 */
927 public AbstractStringBuilder replace(int start, int end, String str) {
928 if (end > count) {
929 end = count;
930 }
931 checkRangeSIOOBE(start, end, count);
932 int len = str.length();
933 int newCount = count + len - (end - start);
934 ensureCapacityInternal(newCount);
935 shift(end, newCount - count);
936 count = newCount;
937 putStringAt(start, str);
938 return this;
939 }
940
941 /**
942 * Returns a new {@code String} that contains a subsequence of
943 * characters currently contained in this character sequence. The
944 * substring begins at the specified index and extends to the end of
945 * this sequence.
946 *
947 * @param start The beginning index, inclusive.
948 * @return The new string.
949 * @throws StringIndexOutOfBoundsException if {@code start} is
950 * less than zero, or greater than the length of this object.
951 */
952 public String substring(int start) {
953 return substring(start, count);
954 }
955
956 /**
957 * Returns a new character sequence that is a subsequence of this sequence.
958 *
959 * <p> An invocation of this method of the form
960 *
961 * <pre>{@code
962 * sb.subSequence(begin, end)}</pre>
963 *
964 * behaves in exactly the same way as the invocation
965 *
966 * <pre>{@code
967 * sb.substring(begin, end)}</pre>
968 *
969 * This method is provided so that this class can
970 * implement the {@link CharSequence} interface.
971 *
972 * @param start the start index, inclusive.
973 * @param end the end index, exclusive.
974 * @return the specified subsequence.
975 *
976 * @throws IndexOutOfBoundsException
977 * if {@code start} or {@code end} are negative,
978 * if {@code end} is greater than {@code length()},
979 * or if {@code start} is greater than {@code end}
980 * @spec JSR-51
981 */
982 @Override
983 public CharSequence subSequence(int start, int end) {
984 return substring(start, end);
985 }
986
987 /**
988 * Returns a new {@code String} that contains a subsequence of
989 * characters currently contained in this sequence. The
990 * substring begins at the specified {@code start} and
991 * extends to the character at index {@code end - 1}.
992 *
993 * @param start The beginning index, inclusive.
994 * @param end The ending index, exclusive.
995 * @return The new string.
996 * @throws StringIndexOutOfBoundsException if {@code start}
997 * or {@code end} are negative or greater than
998 * {@code length()}, or {@code start} is
999 * greater than {@code end}.
1000 */
1001 public String substring(int start, int end) {
1002 checkRangeSIOOBE(start, end, count);
1003 if (isLatin1()) {
1004 return StringLatin1.newString(value, start, end - start);
1005 }
1006 return StringUTF16.newString(value, start, end - start);
1007 }
1008
1009 private void shift(int offset, int n) {
1010 System.arraycopy(value, offset << coder,
1011 value, (offset + n) << coder, (count - offset) << coder);
1012 }
1013
1014 /**
1015 * Inserts the string representation of a subarray of the {@code str}
1016 * array argument into this sequence. The subarray begins at the
1017 * specified {@code offset} and extends {@code len} {@code char}s.
1018 * The characters of the subarray are inserted into this sequence at
1019 * the position indicated by {@code index}. The length of this
1020 * sequence increases by {@code len} {@code char}s.
1021 *
1022 * @param index position at which to insert subarray.
1023 * @param str A {@code char} array.
1024 * @param offset the index of the first {@code char} in subarray to
1025 * be inserted.
1026 * @param len the number of {@code char}s in the subarray to
1027 * be inserted.
1028 * @return This object
1029 * @throws StringIndexOutOfBoundsException if {@code index}
1030 * is negative or greater than {@code length()}, or
1031 * {@code offset} or {@code len} are negative, or
1032 * {@code (offset+len)} is greater than
1033 * {@code str.length}.
1034 */
1035 public AbstractStringBuilder insert(int index, char[] str, int offset,
1036 int len)
1037 {
1038 checkOffset(index, count);
1039 checkRangeSIOOBE(offset, offset + len, str.length);
1040 ensureCapacityInternal(count + len);
1041 shift(index, len);
1042 count += len;
1043 putCharsAt(index, str, offset, offset + len);
1044 return this;
1045 }
1046
1047 /**
1048 * Inserts the string representation of the {@code Object}
1049 * argument into this character sequence.
1050 * <p>
1051 * The overall effect is exactly as if the second argument were
1052 * converted to a string by the method {@link String#valueOf(Object)},
1053 * and the characters of that string were then
1054 * {@link #insert(int,String) inserted} into this character
1055 * sequence at the indicated offset.
1056 * <p>
1057 * The {@code offset} argument must be greater than or equal to
1058 * {@code 0}, and less than or equal to the {@linkplain #length() length}
1059 * of this sequence.
1060 *
1061 * @param offset the offset.
1062 * @param obj an {@code Object}.
1063 * @return a reference to this object.
1064 * @throws StringIndexOutOfBoundsException if the offset is invalid.
1065 */
1066 public AbstractStringBuilder insert(int offset, Object obj) {
1067 return insert(offset, String.valueOf(obj));
1068 }
1069
1070 /**
1071 * Inserts the string into this character sequence.
1072 * <p>
1073 * The characters of the {@code String} argument are inserted, in
1074 * order, into this sequence at the indicated offset, moving up any
1075 * characters originally above that position and increasing the length
1076 * of this sequence by the length of the argument. If
1077 * {@code str} is {@code null}, then the four characters
1078 * {@code "null"} are inserted into this sequence.
1079 * <p>
1080 * The character at index <i>k</i> in the new character sequence is
1081 * equal to:
1082 * <ul>
1083 * <li>the character at index <i>k</i> in the old character sequence, if
1084 * <i>k</i> is less than {@code offset}
1085 * <li>the character at index <i>k</i>{@code -offset} in the
1086 * argument {@code str}, if <i>k</i> is not less than
1087 * {@code offset} but is less than {@code offset+str.length()}
1088 * <li>the character at index <i>k</i>{@code -str.length()} in the
1089 * old character sequence, if <i>k</i> is not less than
1090 * {@code offset+str.length()}
1091 * </ul><p>
1092 * The {@code offset} argument must be greater than or equal to
1093 * {@code 0}, and less than or equal to the {@linkplain #length() length}
1094 * of this sequence.
1095 *
1096 * @param offset the offset.
1097 * @param str a string.
1098 * @return a reference to this object.
1099 * @throws StringIndexOutOfBoundsException if the offset is invalid.
1100 */
1101 public AbstractStringBuilder insert(int offset, String str) {
1102 checkOffset(offset, count);
1103 if (str == null) {
1104 str = "null";
1105 }
1106 int len = str.length();
1107 ensureCapacityInternal(count + len);
1108 shift(offset, len);
1109 count += len;
1110 putStringAt(offset, str);
1111 return this;
1112 }
1113
1114 /**
1115 * Inserts the string representation of the {@code char} array
1116 * argument into this sequence.
1117 * <p>
1118 * The characters of the array argument are inserted into the
1119 * contents of this sequence at the position indicated by
1120 * {@code offset}. The length of this sequence increases by
1121 * the length of the argument.
1122 * <p>
1123 * The overall effect is exactly as if the second argument were
1124 * converted to a string by the method {@link String#valueOf(char[])},
1125 * and the characters of that string were then
1126 * {@link #insert(int,String) inserted} into this character
1127 * sequence at the indicated offset.
1128 * <p>
1129 * The {@code offset} argument must be greater than or equal to
1130 * {@code 0}, and less than or equal to the {@linkplain #length() length}
1131 * of this sequence.
1132 *
1133 * @param offset the offset.
1134 * @param str a character array.
1135 * @return a reference to this object.
1136 * @throws StringIndexOutOfBoundsException if the offset is invalid.
1137 */
1138 public AbstractStringBuilder insert(int offset, char[] str) {
1139 checkOffset(offset, count);
1140 int len = str.length;
1141 ensureCapacityInternal(count + len);
1142 shift(offset, len);
1143 count += len;
1144 putCharsAt(offset, str, 0, len);
1145 return this;
1146 }
1147
1148 /**
1149 * Inserts the specified {@code CharSequence} into this sequence.
1150 * <p>
1151 * The characters of the {@code CharSequence} argument are inserted,
1152 * in order, into this sequence at the indicated offset, moving up
1153 * any characters originally above that position and increasing the length
1154 * of this sequence by the length of the argument s.
1155 * <p>
1156 * The result of this method is exactly the same as if it were an
1157 * invocation of this object's
1158 * {@link #insert(int,CharSequence,int,int) insert}(dstOffset, s, 0, s.length())
1159 * method.
1160 *
1161 * <p>If {@code s} is {@code null}, then the four characters
1162 * {@code "null"} are inserted into this sequence.
1163 *
1164 * @param dstOffset the offset.
1165 * @param s the sequence to be inserted
1166 * @return a reference to this object.
1167 * @throws IndexOutOfBoundsException if the offset is invalid.
1168 */
1169 public AbstractStringBuilder insert(int dstOffset, CharSequence s) {
1170 if (s == null) {
1171 s = "null";
1172 }
1173 if (s instanceof String) {
1174 return this.insert(dstOffset, (String)s);
1175 }
1176 return this.insert(dstOffset, s, 0, s.length());
1177 }
1178
1179 /**
1180 * Inserts a subsequence of the specified {@code CharSequence} into
1181 * this sequence.
1182 * <p>
1183 * The subsequence of the argument {@code s} specified by
1184 * {@code start} and {@code end} are inserted,
1185 * in order, into this sequence at the specified destination offset, moving
1186 * up any characters originally above that position. The length of this
1187 * sequence is increased by {@code end - start}.
1188 * <p>
1189 * The character at index <i>k</i> in this sequence becomes equal to:
1190 * <ul>
1191 * <li>the character at index <i>k</i> in this sequence, if
1192 * <i>k</i> is less than {@code dstOffset}
1193 * <li>the character at index <i>k</i>{@code +start-dstOffset} in
1194 * the argument {@code s}, if <i>k</i> is greater than or equal to
1195 * {@code dstOffset} but is less than {@code dstOffset+end-start}
1196 * <li>the character at index <i>k</i>{@code -(end-start)} in this
1197 * sequence, if <i>k</i> is greater than or equal to
1198 * {@code dstOffset+end-start}
1199 * </ul><p>
1200 * The {@code dstOffset} argument must be greater than or equal to
1201 * {@code 0}, and less than or equal to the {@linkplain #length() length}
1202 * of this sequence.
1203 * <p>The start argument must be nonnegative, and not greater than
1204 * {@code end}.
1205 * <p>The end argument must be greater than or equal to
1206 * {@code start}, and less than or equal to the length of s.
1207 *
1208 * <p>If {@code s} is {@code null}, then this method inserts
1209 * characters as if the s parameter was a sequence containing the four
1210 * characters {@code "null"}.
1211 *
1212 * @param dstOffset the offset in this sequence.
1213 * @param s the sequence to be inserted.
1214 * @param start the starting index of the subsequence to be inserted.
1215 * @param end the end index of the subsequence to be inserted.
1216 * @return a reference to this object.
1217 * @throws IndexOutOfBoundsException if {@code dstOffset}
1218 * is negative or greater than {@code this.length()}, or
1219 * {@code start} or {@code end} are negative, or
1220 * {@code start} is greater than {@code end} or
1221 * {@code end} is greater than {@code s.length()}
1222 */
1223 public AbstractStringBuilder insert(int dstOffset, CharSequence s,
1224 int start, int end)
1225 {
1226 if (s == null) {
1227 s = "null";
1228 }
1229 checkOffset(dstOffset, count);
1230 checkRange(start, end, s.length());
1231 int len = end - start;
1232 ensureCapacityInternal(count + len);
1233 shift(dstOffset, len);
1234 count += len;
1235 putCharsAt(dstOffset, s, start, end);
1236 return this;
1237 }
1238
1239 /**
1240 * Inserts the string representation of the {@code boolean}
1241 * argument into this sequence.
1242 * <p>
1243 * The overall effect is exactly as if the second argument were
1244 * converted to a string by the method {@link String#valueOf(boolean)},
1245 * and the characters of that string were then
1246 * {@link #insert(int,String) inserted} into this character
1247 * sequence at the indicated offset.
1248 * <p>
1249 * The {@code offset} argument must be greater than or equal to
1250 * {@code 0}, and less than or equal to the {@linkplain #length() length}
1251 * of this sequence.
1252 *
1253 * @param offset the offset.
1254 * @param b a {@code boolean}.
1255 * @return a reference to this object.
1256 * @throws StringIndexOutOfBoundsException if the offset is invalid.
1257 */
1258 public AbstractStringBuilder insert(int offset, boolean b) {
1259 return insert(offset, String.valueOf(b));
1260 }
1261
1262 /**
1263 * Inserts the string representation of the {@code char}
1264 * argument into this sequence.
1265 * <p>
1266 * The overall effect is exactly as if the second argument were
1267 * converted to a string by the method {@link String#valueOf(char)},
1268 * and the character in that string were then
1269 * {@link #insert(int,String) inserted} into this character
1270 * sequence at the indicated offset.
1271 * <p>
1272 * The {@code offset} argument must be greater than or equal to
1273 * {@code 0}, and less than or equal to the {@linkplain #length() length}
1274 * of this sequence.
1275 *
1276 * @param offset the offset.
1277 * @param c a {@code char}.
1278 * @return a reference to this object.
1279 * @throws IndexOutOfBoundsException if the offset is invalid.
1280 */
1281 public AbstractStringBuilder insert(int offset, char c) {
1282 checkOffset(offset, count);
1283 ensureCapacityInternal(count + 1);
1284 shift(offset, 1);
1285 count += 1;
1286 if (isLatin1() && StringLatin1.canEncode(c)) {
1287 value[offset] = (byte)c;
1288 } else {
1289 if (isLatin1()) {
1290 inflate();
1291 }
1292 StringUTF16.putCharSB(value, offset, c);
1293 }
1294 return this;
1295 }
1296
1297 /**
1298 * Inserts the string representation of the second {@code int}
1299 * argument into this sequence.
1300 * <p>
1301 * The overall effect is exactly as if the second argument were
1302 * converted to a string by the method {@link String#valueOf(int)},
1303 * and the characters of that string were then
1304 * {@link #insert(int,String) inserted} into this character
1305 * sequence at the indicated offset.
1306 * <p>
1307 * The {@code offset} argument must be greater than or equal to
1308 * {@code 0}, and less than or equal to the {@linkplain #length() length}
1309 * of this sequence.
1310 *
1311 * @param offset the offset.
1312 * @param i an {@code int}.
1313 * @return a reference to this object.
1314 * @throws StringIndexOutOfBoundsException if the offset is invalid.
1315 */
1316 public AbstractStringBuilder insert(int offset, int i) {
1317 return insert(offset, String.valueOf(i));
1318 }
1319
1320 /**
1321 * Inserts the string representation of the {@code long}
1322 * argument into this sequence.
1323 * <p>
1324 * The overall effect is exactly as if the second argument were
1325 * converted to a string by the method {@link String#valueOf(long)},
1326 * and the characters of that string were then
1327 * {@link #insert(int,String) inserted} into this character
1328 * sequence at the indicated offset.
1329 * <p>
1330 * The {@code offset} argument must be greater than or equal to
1331 * {@code 0}, and less than or equal to the {@linkplain #length() length}
1332 * of this sequence.
1333 *
1334 * @param offset the offset.
1335 * @param l a {@code long}.
1336 * @return a reference to this object.
1337 * @throws StringIndexOutOfBoundsException if the offset is invalid.
1338 */
1339 public AbstractStringBuilder insert(int offset, long l) {
1340 return insert(offset, String.valueOf(l));
1341 }
1342
1343 /**
1344 * Inserts the string representation of the {@code float}
1345 * argument into this sequence.
1346 * <p>
1347 * The overall effect is exactly as if the second argument were
1348 * converted to a string by the method {@link String#valueOf(float)},
1349 * and the characters of that string were then
1350 * {@link #insert(int,String) inserted} into this character
1351 * sequence at the indicated offset.
1352 * <p>
1353 * The {@code offset} argument must be greater than or equal to
1354 * {@code 0}, and less than or equal to the {@linkplain #length() length}
1355 * of this sequence.
1356 *
1357 * @param offset the offset.
1358 * @param f a {@code float}.
1359 * @return a reference to this object.
1360 * @throws StringIndexOutOfBoundsException if the offset is invalid.
1361 */
1362 public AbstractStringBuilder insert(int offset, float f) {
1363 return insert(offset, String.valueOf(f));
1364 }
1365
1366 /**
1367 * Inserts the string representation of the {@code double}
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(double)},
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 d a {@code double}.
1382 * @return a reference to this object.
1383 * @throws StringIndexOutOfBoundsException if the offset is invalid.
1384 */
1385 public AbstractStringBuilder insert(int offset, double d) {
1386 return insert(offset, String.valueOf(d));
1387 }
1388
1389 /**
1390 * Returns the index within this string of the first occurrence of the
1391 * specified substring.
1392 *
1393 * <p>The returned index is the smallest value {@code k} for which:
1394 * <pre>{@code
1395 * this.toString().startsWith(str, k)
1396 * }</pre>
1397 * If no such value of {@code k} exists, then {@code -1} is returned.
1398 *
1399 * @param str the substring to search for.
1400 * @return the index of the first occurrence of the specified substring,
1401 * or {@code -1} if there is no such occurrence.
1402 */
1403 public int indexOf(String str) {
1404 return indexOf(str, 0);
1405 }
1406
1407 /**
1408 * Returns the index within this string of the first occurrence of the
1409 * specified substring, starting at the specified index.
1410 *
1411 * <p>The returned index is the smallest value {@code k} for which:
1412 * <pre>{@code
1413 * k >= Math.min(fromIndex, this.length()) &&
1414 * this.toString().startsWith(str, k)
1415 * }</pre>
1416 * If no such value of {@code k} exists, then {@code -1} is returned.
1417 *
1418 * @param str the substring to search for.
1419 * @param fromIndex the index from which to start the search.
1420 * @return the index of the first occurrence of the specified substring,
1421 * starting at the specified index,
1422 * or {@code -1} if there is no such occurrence.
1423 */
1424 public int indexOf(String str, int fromIndex) {
1425 return String.indexOf(value, coder, count, str, fromIndex);
1426 }
1427
1428 /**
1429 * Returns the index within this string of the last occurrence of the
1430 * specified substring. The last occurrence of the empty string "" is
1431 * considered to occur at the index value {@code this.length()}.
1432 *
1433 * <p>The returned index is the largest value {@code k} for which:
1434 * <pre>{@code
1435 * this.toString().startsWith(str, k)
1436 * }</pre>
1437 * If no such value of {@code k} exists, then {@code -1} is returned.
1438 *
1439 * @param str the substring to search for.
1440 * @return the index of the last occurrence of the specified substring,
1441 * or {@code -1} if there is no such occurrence.
1442 */
1443 public int lastIndexOf(String str) {
1444 return lastIndexOf(str, count);
1445 }
1446
1447 /**
1448 * Returns the index within this string of the last occurrence of the
1449 * specified substring, searching backward starting at the specified index.
1450 *
1451 * <p>The returned index is the largest value {@code k} for which:
1452 * <pre>{@code
1453 * k <= Math.min(fromIndex, this.length()) &&
1454 * this.toString().startsWith(str, k)
1455 * }</pre>
1456 * If no such value of {@code k} exists, then {@code -1} is returned.
1457 *
1458 * @param str the substring to search for.
1459 * @param fromIndex the index to start the search from.
1460 * @return the index of the last occurrence of the specified substring,
1461 * searching backward from the specified index,
1462 * or {@code -1} if there is no such occurrence.
1463 */
1464 public int lastIndexOf(String str, int fromIndex) {
1465 return String.lastIndexOf(value, coder, count, str, fromIndex);
1466 }
1467
1468 /**
1469 * Causes this character sequence to be replaced by the reverse of
1470 * the sequence. If there are any surrogate pairs included in the
1471 * sequence, these are treated as single characters for the
1472 * reverse operation. Thus, the order of the high-low surrogates
1473 * is never reversed.
1474 *
1475 * Let <i>n</i> be the character length of this character sequence
1476 * (not the length in {@code char} values) just prior to
1477 * execution of the {@code reverse} method. Then the
1478 * character at index <i>k</i> in the new character sequence is
1479 * equal to the character at index <i>n-k-1</i> in the old
1480 * character sequence.
1481 *
1482 * <p>Note that the reverse operation may result in producing
1483 * surrogate pairs that were unpaired low-surrogates and
1484 * high-surrogates before the operation. For example, reversing
1485 * "\u005CuDC00\u005CuD800" produces "\u005CuD800\u005CuDC00" which is
1486 * a valid surrogate pair.
1487 *
1488 * @return a reference to this object.
1489 */
1490 public AbstractStringBuilder reverse() {
1491 byte[] val = this.value;
1492 int count = this.count;
1493 int coder = this.coder;
1494 int n = count - 1;
1495 if (COMPACT_STRINGS && coder == LATIN1) {
1496 for (int j = (n-1) >> 1; j >= 0; j--) {
1497 int k = n - j;
1498 byte cj = val[j];
1499 val[j] = val[k];
1500 val[k] = cj;
1501 }
1502 } else {
1503 checkOffset(count, val.length >> 1);
1504 boolean hasSurrogates = false;
1505 for (int j = (n-1) >> 1; j >= 0; j--) {
1506 int k = n - j;
1507 char cj = StringUTF16.getChar(val, j);
1508 char ck = StringUTF16.getChar(val, k);
1509 StringUTF16.putChar(val, j, ck);
1510 StringUTF16.putChar(val, k, cj);
1511 if (Character.isSurrogate(cj) ||
1512 Character.isSurrogate(ck)) {
1513 hasSurrogates = true;
1514 }
1515 }
1516 if (hasSurrogates) {
1517 reverseAllValidSurrogatePairs(val, count);
1518 }
1519 }
1520 return this;
1521 }
1522
1523 /** Outlined helper method for reverse() */
1524 private void reverseAllValidSurrogatePairs(byte[] val, int count) {
1525 for (int i = 0; i < count - 1; i++) {
1526 char c2 = StringUTF16.getChar(val, i);
1527 if (Character.isLowSurrogate(c2)) {
1528 char c1 = StringUTF16.getChar(val, i + 1);
1529 if (Character.isHighSurrogate(c1)) {
1530 StringUTF16.putChar(val, i++, c1);
1531 StringUTF16.putChar(val, i, c2);
1532 }
1533 }
1534 }
1535 }
1536
1537 /**
1538 * Returns a string representing the data in this sequence.
1539 * A new {@code String} object is allocated and initialized to
1540 * contain the character sequence currently represented by this
1541 * object. This {@code String} is then returned. Subsequent
1542 * changes to this sequence do not affect the contents of the
1543 * {@code String}.
1544 *
1545 * @return a string representation of this sequence of characters.
1546 */
1547 @Override
1548 public abstract String toString();
1549
1550 /**
1551 * {@inheritDoc}
1552 * @since 9
1553 */
1554 @Override
1555 public IntStream chars() {
1556 // Reuse String-based spliterator. This requires a supplier to
1557 // capture the value and count when the terminal operation is executed
1558 return StreamSupport.intStream(
1559 () -> {
1560 // The combined set of field reads are not atomic and thread
1561 // safe but bounds checks will ensure no unsafe reads from
1562 // the byte array
1563 byte[] val = this.value;
1564 int count = this.count;
1565 byte coder = this.coder;
1566 return coder == LATIN1
1567 ? new StringLatin1.CharsSpliterator(val, 0, count, 0)
1568 : new StringUTF16.CharsSpliterator(val, 0, count, 0);
1569 },
1570 Spliterator.ORDERED | Spliterator.SIZED | Spliterator.SUBSIZED,
1571 false);
1572 }
1573
1574 /**
1575 * {@inheritDoc}
1576 * @since 9
1577 */
1578 @Override
1579 public IntStream codePoints() {
1580 // Reuse String-based spliterator. This requires a supplier to
1581 // capture the value and count when the terminal operation is executed
1582 return StreamSupport.intStream(
1583 () -> {
1584 // The combined set of field reads are not atomic and thread
1585 // safe but bounds checks will ensure no unsafe reads from
1586 // the byte array
1587 byte[] val = this.value;
1588 int count = this.count;
1589 byte coder = this.coder;
1590 return coder == LATIN1
1591 ? new StringLatin1.CharsSpliterator(val, 0, count, 0)
1592 : new StringUTF16.CodePointsSpliterator(val, 0, count, 0);
1593 },
1594 Spliterator.ORDERED,
1595 false);
1596 }
1597
1598 /**
1599 * Needed by {@code String} for the contentEquals method.
1600 */
1601 final byte[] getValue() {
1602 return value;
1603 }
1604
1605 /*
1606 * Invoker guarantees it is in UTF16 (inflate itself for asb), if two
1607 * coders are different and the dstBegin has enough space
1608 *
1609 * @param dstBegin the char index, not offset of byte[]
1610 * @param coder the coder of dst[]
1611 */
1612 void getBytes(byte dst[], int dstBegin, byte coder) {
1613 if (this.coder == coder) {
1614 System.arraycopy(value, 0, dst, dstBegin << coder, count << coder);
1615 } else { // this.coder == LATIN && coder == UTF16
1616 StringLatin1.inflate(value, 0, dst, dstBegin, count);
1617 }
1618 }
1619
1620 /* for readObject() */
1621 void initBytes(char[] value, int off, int len) {
1622 if (String.COMPACT_STRINGS) {
1623 this.value = StringUTF16.compress(value, off, len);
1624 if (this.value != null) {
1625 this.coder = LATIN1;
1626 return;
1627 }
1628 }
1629 this.coder = UTF16;
1630 this.value = StringUTF16.toBytes(value, off, len);
1631 }
1632
1633 final byte getCoder() {
1634 return COMPACT_STRINGS ? coder : UTF16;
1635 }
1636
1637 final boolean isLatin1() {
1638 return COMPACT_STRINGS && coder == LATIN1;
1639 }
1640
1641 private final void putCharsAt(int index, char[] s, int off, int end) {
1642 if (isLatin1()) {
1643 byte[] val = this.value;
1644 for (int i = off, j = index; i < end; i++) {
1645 char c = s[i];
1646 if (StringLatin1.canEncode(c)) {
1647 val[j++] = (byte)c;
1648 } else {
1649 inflate();
1650 StringUTF16.putCharsSB(this.value, j, s, i, end);
1651 return;
1652 }
1653 }
1654 } else {
1655 StringUTF16.putCharsSB(this.value, index, s, off, end);
1656 }
1657 }
1658
1659 private final void putCharsAt(int index, CharSequence s, int off, int end) {
1660 if (isLatin1()) {
1661 byte[] val = this.value;
1662 for (int i = off, j = index; i < end; i++) {
1663 char c = s.charAt(i);
1664 if (StringLatin1.canEncode(c)) {
1665 val[j++] = (byte)c;
1666 } else {
1667 inflate();
1668 StringUTF16.putCharsSB(this.value, j, s, i, end);
1669 return;
1670 }
1671 }
1672 } else {
1673 StringUTF16.putCharsSB(this.value, index, s, off, end);
1674 }
1675 }
1676
1677 private final void putStringAt(int index, String str) {
1678 if (getCoder() != str.coder()) {
1679 inflate();
1680 }
1681 str.getBytes(value, index, coder);
1682 }
1683
1684 private final void appendChars(char[] s, int off, int end) {
1685 if (isLatin1()) {
1686 byte[] val = this.value;
1687 for (int i = off, j = count; i < end; i++) {
1688 char c = s[i];
1689 if (StringLatin1.canEncode(c)) {
1690 val[j++] = (byte)c;
1691 } else {
1692 count = j;
1693 inflate();
1694 StringUTF16.putCharsSB(this.value, j, s, i, end);
1695 count += end - i;
1696 return;
1697 }
1698 }
1699 } else {
1700 StringUTF16.putCharsSB(this.value, count, s, off, end);
1701 }
1702 count += end - off;
1703 }
1704
1705 private final void appendChars(CharSequence s, int off, int end) {
1706 if (isLatin1()) {
1707 byte[] val = this.value;
1708 for (int i = off, j = count; i < end; i++) {
1709 char c = s.charAt(i);
1710 if (StringLatin1.canEncode(c)) {
1711 val[j++] = (byte)c;
1712 } else {
1713 count = j;
1714 inflate();
1715 StringUTF16.putCharsSB(this.value, j, s, i, end);
1716 count += end - i;
1717 return;
1718 }
1719 }
1720 } else {
1721 StringUTF16.putCharsSB(this.value, count, s, off, end);
1722 }
1723 count += end - off;
1724 }
1725
1726 /* IndexOutOfBoundsException, if out of bounds */
1727 private static void checkRange(int start, int end, int len) {
1728 if (start < 0 || start > end || end > len) {
1729 throw new IndexOutOfBoundsException(
1730 "start " + start + ", end " + end + ", length " + len);
1731 }
1732 }
1733
1734 /* StringIndexOutOfBoundsException, if out of bounds */
1735 private static void checkRangeSIOOBE(int start, int end, int len) {
1736 if (start < 0 || start > end || end > len) {
1737 throw new StringIndexOutOfBoundsException(
1738 "start " + start + ", end " + end + ", length " + len);
1739 }
1740 }
1741 }