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 if (s instanceof CharRepetitions) {
551 CharRepetitions cr = (CharRepetitions) s;
552 return this.appendN(cr.getChar(), cr.length());
553 }
554 return this.append(s, 0, s.length());
555 }
556
557 private AbstractStringBuilder appendNull() {
558 ensureCapacityInternal(count + 4);
559 int count = this.count;
560 byte[] val = this.value;
561 if (isLatin1()) {
562 val[count++] = 'n';
563 val[count++] = 'u';
564 val[count++] = 'l';
565 val[count++] = 'l';
566 } else {
567 checkOffset(count + 4, val.length >> 1);
568 StringUTF16.putChar(val, count++, 'n');
569 StringUTF16.putChar(val, count++, 'u');
570 StringUTF16.putChar(val, count++, 'l');
571 StringUTF16.putChar(val, count++, 'l');
572 }
573 this.count = count;
574 return this;
575 }
576
577 /**
578 * Appends a subsequence of the specified {@code CharSequence} to this
579 * sequence.
580 * <p>
581 * Characters of the argument {@code s}, starting at
582 * index {@code start}, are appended, in order, to the contents of
583 * this sequence up to the (exclusive) index {@code end}. The length
584 * of this sequence is increased by the value of {@code end - start}.
585 * <p>
586 * Let <i>n</i> be the length of this character sequence just prior to
587 * execution of the {@code append} method. Then the character at
588 * index <i>k</i> in this character sequence becomes equal to the
589 * character at index <i>k</i> in this sequence, if <i>k</i> is less than
590 * <i>n</i>; otherwise, it is equal to the character at index
591 * <i>k+start-n</i> in the argument {@code s}.
592 * <p>
593 * If {@code s} is {@code null}, then this method appends
594 * characters as if the s parameter was a sequence containing the four
595 * characters {@code "null"}.
596 *
597 * @param s the sequence to append.
598 * @param start the starting index of the subsequence to be appended.
599 * @param end the end index of the subsequence to be appended.
600 * @return a reference to this object.
601 * @throws IndexOutOfBoundsException if
602 * {@code start} is negative, or
603 * {@code start} is greater than {@code end} or
604 * {@code end} is greater than {@code s.length()}
605 */
606 @Override
607 public AbstractStringBuilder append(CharSequence s, int start, int end) {
608 if (s == null) {
609 s = "null";
610 }
611 checkRange(start, end, s.length());
612 int len = end - start;
613 ensureCapacityInternal(count + len);
614 appendChars(s, start, end);
615 return this;
616 }
617
618 /**
619 * Appends the string representation of the {@code char} array
620 * argument to this sequence.
621 * <p>
622 * The characters of the array argument are appended, in order, to
623 * the contents of this sequence. The length of this sequence
624 * increases by the length of the argument.
625 * <p>
626 * The overall effect is exactly as if the argument were converted
627 * to a string by the method {@link String#valueOf(char[])},
628 * and the characters of that string were then
629 * {@link #append(String) appended} to this character sequence.
630 *
631 * @param str the characters to be appended.
632 * @return a reference to this object.
633 */
634 public AbstractStringBuilder append(char[] str) {
635 int len = str.length;
636 ensureCapacityInternal(count + len);
637 appendChars(str, 0, len);
638 return this;
639 }
640
641 /**
642 * Appends the string representation of a subarray of the
643 * {@code char} array argument to this sequence.
644 * <p>
645 * Characters of the {@code char} array {@code str}, starting at
646 * index {@code offset}, are appended, in order, to the contents
647 * of this sequence. The length of this sequence increases
648 * by the value of {@code len}.
649 * <p>
650 * The overall effect is exactly as if the arguments were converted
651 * to a string by the method {@link String#valueOf(char[],int,int)},
652 * and the characters of that string were then
653 * {@link #append(String) appended} to this character sequence.
654 *
655 * @param str the characters to be appended.
656 * @param offset the index of the first {@code char} to append.
657 * @param len the number of {@code char}s to append.
658 * @return a reference to this object.
659 * @throws IndexOutOfBoundsException
660 * if {@code offset < 0} or {@code len < 0}
661 * or {@code offset+len > str.length}
662 */
663 public AbstractStringBuilder append(char str[], int offset, int len) {
664 int end = offset + len;
665 checkRange(offset, end, str.length);
666 ensureCapacityInternal(count + len);
667 appendChars(str, offset, end);
668 return this;
669 }
670
671 /**
672 * Appends the string representation of the {@code boolean}
673 * argument to the sequence.
674 * <p>
675 * The overall effect is exactly as if the argument were converted
676 * to a string by the method {@link String#valueOf(boolean)},
677 * and the characters of that string were then
678 * {@link #append(String) appended} to this character sequence.
679 *
680 * @param b a {@code boolean}.
681 * @return a reference to this object.
682 */
683 public AbstractStringBuilder append(boolean b) {
684 ensureCapacityInternal(count + (b ? 4 : 5));
685 int count = this.count;
686 byte[] val = this.value;
687 if (isLatin1()) {
688 if (b) {
689 val[count++] = 't';
690 val[count++] = 'r';
691 val[count++] = 'u';
692 val[count++] = 'e';
693 } else {
694 val[count++] = 'f';
695 val[count++] = 'a';
696 val[count++] = 'l';
697 val[count++] = 's';
698 val[count++] = 'e';
699 }
700 } else {
701 if (b) {
702 checkOffset(count + 4, val.length >> 1);
703 StringUTF16.putChar(val, count++, 't');
704 StringUTF16.putChar(val, count++, 'r');
705 StringUTF16.putChar(val, count++, 'u');
706 StringUTF16.putChar(val, count++, 'e');
707 } else {
708 checkOffset(count + 5, val.length >> 1);
709 StringUTF16.putChar(val, count++, 'f');
710 StringUTF16.putChar(val, count++, 'a');
711 StringUTF16.putChar(val, count++, 'l');
712 StringUTF16.putChar(val, count++, 's');
713 StringUTF16.putChar(val, count++, 'e');
714 }
715 }
716 this.count = count;
717 return this;
718 }
719
720 /**
721 * Appends the string representation of the {@code char}
722 * argument to this sequence.
723 * <p>
724 * The argument is appended to the contents of this sequence.
725 * The length of this sequence increases by {@code 1}.
726 * <p>
727 * The overall effect is exactly as if the argument were converted
728 * to a string by the method {@link String#valueOf(char)},
729 * and the character in that string were then
730 * {@link #append(String) appended} to this character sequence.
731 *
732 * @param c a {@code char}.
733 * @return a reference to this object.
734 */
735 @Override
736 public AbstractStringBuilder append(char c) {
737 ensureCapacityInternal(count + 1);
738 if (isLatin1() && StringLatin1.canEncode(c)) {
739 value[count++] = (byte)c;
740 } else {
741 if (isLatin1()) {
742 inflate();
743 }
744 StringUTF16.putCharSB(value, count++, c);
745 }
746 return this;
747 }
748
749 /**
750 * Appends {@code n} copies of the string representation of
751 * the {@code char} argument to this sequence.
752 * <p>
753 * The first argument is appended to the contents of this
754 * sequence specified amount of times.
755 * The length of this sequence increases by {@code n}.
756 * <p>
757 * The overall effect is exactly as if the first argument
758 * were converted to a string by the method
759 * {@link String#valueOf(char)}, and the character in that
760 * string were then {@link #append(String) appended} to this
761 * character sequence {@code n} times.
762 *
763 * @param c a {@code char}.
764 * @param n a number of copies to append.
765 * @return a reference to this object.
766 * @throws IllegalArgumentException if {@code n < 0}.
767 */
768 @Override
769 public AbstractStringBuilder appendN(char c, int n) {
770 if (n <= 0) {
771 if (n < 0) {
772 throw new IllegalArgumentException(
773 "Negative number of copies: " + n);
774 }
775 } else {
776 int count = this.count;
777 ensureCapacityInternal(count + n);
778 if (isLatin1() && StringLatin1.canEncode(c)) {
779 byte b = (byte)c;
780 do {
781 value[count++] = b;
782 } while (--n > 0);
783 } else {
784 if (isLatin1()) {
785 inflate();
786 }
787 do {
788 StringUTF16.putCharSB(value, count++, c);
789 } while (--n > 0);
790 }
791 this.count = count;
792 }
793 return this;
794 }
795
796 /**
797 * Appends the string representation of the {@code int}
798 * argument to this sequence.
799 * <p>
800 * The overall effect is exactly as if the argument were converted
801 * to a string by the method {@link String#valueOf(int)},
802 * and the characters of that string were then
803 * {@link #append(String) appended} to this character sequence.
804 *
805 * @param i an {@code int}.
806 * @return a reference to this object.
807 */
808 public AbstractStringBuilder append(int i) {
809 int spaceNeeded = count + Integer.stringSize(i);
810 ensureCapacityInternal(spaceNeeded);
811 if (isLatin1()) {
812 Integer.getChars(i, spaceNeeded, value);
813 } else {
814 byte[] val = this.value;
815 checkOffset(spaceNeeded, val.length >> 1);
816 Integer.getCharsUTF16(i, spaceNeeded, val);
817 }
818 count = spaceNeeded;
819 return this;
820 }
821
822 /**
823 * Appends the string representation of the {@code long}
824 * argument to this sequence.
825 * <p>
826 * The overall effect is exactly as if the argument were converted
827 * to a string by the method {@link String#valueOf(long)},
828 * and the characters of that string were then
829 * {@link #append(String) appended} to this character sequence.
830 *
831 * @param l a {@code long}.
832 * @return a reference to this object.
833 */
834 public AbstractStringBuilder append(long l) {
835 int spaceNeeded = count + Long.stringSize(l);
836 ensureCapacityInternal(spaceNeeded);
837 if (isLatin1()) {
838 Long.getChars(l, spaceNeeded, value);
839 } else {
840 byte[] val = this.value;
841 checkOffset(spaceNeeded, val.length >> 1);
842 Long.getCharsUTF16(l, spaceNeeded, val);
843 }
844 count = spaceNeeded;
845 return this;
846 }
847
848 /**
849 * Appends the string representation of the {@code float}
850 * argument to this sequence.
851 * <p>
852 * The overall effect is exactly as if the argument were converted
853 * to a string by the method {@link String#valueOf(float)},
854 * and the characters of that string were then
855 * {@link #append(String) appended} to this character sequence.
856 *
857 * @param f a {@code float}.
858 * @return a reference to this object.
859 */
860 public AbstractStringBuilder append(float f) {
861 FloatingDecimal.appendTo(f,this);
862 return this;
863 }
864
865 /**
866 * Appends the string representation of the {@code double}
867 * argument to this sequence.
868 * <p>
869 * The overall effect is exactly as if the argument were converted
870 * to a string by the method {@link String#valueOf(double)},
871 * and the characters of that string were then
872 * {@link #append(String) appended} to this character sequence.
873 *
874 * @param d a {@code double}.
875 * @return a reference to this object.
876 */
877 public AbstractStringBuilder append(double d) {
878 FloatingDecimal.appendTo(d,this);
879 return this;
880 }
881
882 /**
883 * Removes the characters in a substring of this sequence.
884 * The substring begins at the specified {@code start} and extends to
885 * the character at index {@code end - 1} or to the end of the
886 * sequence if no such character exists. If
887 * {@code start} is equal to {@code end}, no changes are made.
888 *
889 * @param start The beginning index, inclusive.
890 * @param end The ending index, exclusive.
891 * @return This object.
892 * @throws StringIndexOutOfBoundsException if {@code start}
893 * is negative, greater than {@code length()}, or
894 * greater than {@code end}.
895 */
896 public AbstractStringBuilder delete(int start, int end) {
897 if (end > count) {
898 end = count;
899 }
900 checkRangeSIOOBE(start, end, count);
901 int len = end - start;
902 if (len > 0) {
903 shift(end, -len);
904 count -= len;
905 }
906 return this;
907 }
908
909 /**
910 * Appends the string representation of the {@code codePoint}
911 * argument to this sequence.
912 *
913 * <p> The argument is appended to the contents of this sequence.
914 * The length of this sequence increases by
915 * {@link Character#charCount(int) Character.charCount(codePoint)}.
916 *
917 * <p> The overall effect is exactly as if the argument were
918 * converted to a {@code char} array by the method
919 * {@link Character#toChars(int)} and the character in that array
920 * were then {@link #append(char[]) appended} to this character
921 * sequence.
922 *
923 * @param codePoint a Unicode code point
924 * @return a reference to this object.
925 * @exception IllegalArgumentException if the specified
926 * {@code codePoint} isn't a valid Unicode code point
927 */
928 public AbstractStringBuilder appendCodePoint(int codePoint) {
929 if (Character.isBmpCodePoint(codePoint)) {
930 return append((char)codePoint);
931 }
932 return append(Character.toChars(codePoint));
933 }
934
935 /**
936 * Removes the {@code char} at the specified position in this
937 * sequence. This sequence is shortened by one {@code char}.
938 *
939 * <p>Note: If the character at the given index is a supplementary
940 * character, this method does not remove the entire character. If
941 * correct handling of supplementary characters is required,
942 * determine the number of {@code char}s to remove by calling
943 * {@code Character.charCount(thisSequence.codePointAt(index))},
944 * where {@code thisSequence} is this sequence.
945 *
946 * @param index Index of {@code char} to remove
947 * @return This object.
948 * @throws StringIndexOutOfBoundsException if the {@code index}
949 * is negative or greater than or equal to
950 * {@code length()}.
951 */
952 public AbstractStringBuilder deleteCharAt(int index) {
953 checkIndex(index, count);
954 shift(index + 1, -1);
955 count--;
956 return this;
957 }
958
959 /**
960 * Replaces the characters in a substring of this sequence
961 * with characters in the specified {@code String}. The substring
962 * begins at the specified {@code start} and extends to the character
963 * at index {@code end - 1} or to the end of the
964 * sequence if no such character exists. First the
965 * characters in the substring are removed and then the specified
966 * {@code String} is inserted at {@code start}. (This
967 * sequence will be lengthened to accommodate the
968 * specified String if necessary.)
969 *
970 * @param start The beginning index, inclusive.
971 * @param end The ending index, exclusive.
972 * @param str String that will replace previous contents.
973 * @return This object.
974 * @throws StringIndexOutOfBoundsException if {@code start}
975 * is negative, greater than {@code length()}, or
976 * greater than {@code end}.
977 */
978 public AbstractStringBuilder replace(int start, int end, String str) {
979 if (end > count) {
980 end = count;
981 }
982 checkRangeSIOOBE(start, end, count);
983 int len = str.length();
984 int newCount = count + len - (end - start);
985 ensureCapacityInternal(newCount);
986 shift(end, newCount - count);
987 count = newCount;
988 putStringAt(start, str);
989 return this;
990 }
991
992 /**
993 * Returns a new {@code String} that contains a subsequence of
994 * characters currently contained in this character sequence. The
995 * substring begins at the specified index and extends to the end of
996 * this sequence.
997 *
998 * @param start The beginning index, inclusive.
999 * @return The new string.
1000 * @throws StringIndexOutOfBoundsException if {@code start} is
1001 * less than zero, or greater than the length of this object.
1002 */
1003 public String substring(int start) {
1004 return substring(start, count);
1005 }
1006
1007 /**
1008 * Returns a new character sequence that is a subsequence of this sequence.
1009 *
1010 * <p> An invocation of this method of the form
1011 *
1012 * <pre>{@code
1013 * sb.subSequence(begin, end)}</pre>
1014 *
1015 * behaves in exactly the same way as the invocation
1016 *
1017 * <pre>{@code
1018 * sb.substring(begin, end)}</pre>
1019 *
1020 * This method is provided so that this class can
1021 * implement the {@link CharSequence} interface.
1022 *
1023 * @param start the start index, inclusive.
1024 * @param end the end index, exclusive.
1025 * @return the specified subsequence.
1026 *
1027 * @throws IndexOutOfBoundsException
1028 * if {@code start} or {@code end} are negative,
1029 * if {@code end} is greater than {@code length()},
1030 * or if {@code start} is greater than {@code end}
1031 * @spec JSR-51
1032 */
1033 @Override
1034 public CharSequence subSequence(int start, int end) {
1035 return substring(start, end);
1036 }
1037
1038 /**
1039 * Returns a new {@code String} that contains a subsequence of
1040 * characters currently contained in this sequence. The
1041 * substring begins at the specified {@code start} and
1042 * extends to the character at index {@code end - 1}.
1043 *
1044 * @param start The beginning index, inclusive.
1045 * @param end The ending index, exclusive.
1046 * @return The new string.
1047 * @throws StringIndexOutOfBoundsException if {@code start}
1048 * or {@code end} are negative or greater than
1049 * {@code length()}, or {@code start} is
1050 * greater than {@code end}.
1051 */
1052 public String substring(int start, int end) {
1053 checkRangeSIOOBE(start, end, count);
1054 if (isLatin1()) {
1055 return StringLatin1.newString(value, start, end - start);
1056 }
1057 return StringUTF16.newString(value, start, end - start);
1058 }
1059
1060 private void shift(int offset, int n) {
1061 System.arraycopy(value, offset << coder,
1062 value, (offset + n) << coder, (count - offset) << coder);
1063 }
1064
1065 /**
1066 * Inserts the string representation of a subarray of the {@code str}
1067 * array argument into this sequence. The subarray begins at the
1068 * specified {@code offset} and extends {@code len} {@code char}s.
1069 * The characters of the subarray are inserted into this sequence at
1070 * the position indicated by {@code index}. The length of this
1071 * sequence increases by {@code len} {@code char}s.
1072 *
1073 * @param index position at which to insert subarray.
1074 * @param str A {@code char} array.
1075 * @param offset the index of the first {@code char} in subarray to
1076 * be inserted.
1077 * @param len the number of {@code char}s in the subarray to
1078 * be inserted.
1079 * @return This object
1080 * @throws StringIndexOutOfBoundsException if {@code index}
1081 * is negative or greater than {@code length()}, or
1082 * {@code offset} or {@code len} are negative, or
1083 * {@code (offset+len)} is greater than
1084 * {@code str.length}.
1085 */
1086 public AbstractStringBuilder insert(int index, char[] str, int offset,
1087 int len)
1088 {
1089 checkOffset(index, count);
1090 checkRangeSIOOBE(offset, offset + len, str.length);
1091 ensureCapacityInternal(count + len);
1092 shift(index, len);
1093 count += len;
1094 putCharsAt(index, str, offset, offset + len);
1095 return this;
1096 }
1097
1098 /**
1099 * Inserts the string representation of the {@code Object}
1100 * argument into this character sequence.
1101 * <p>
1102 * The overall effect is exactly as if the second argument were
1103 * converted to a string by the method {@link String#valueOf(Object)},
1104 * and the characters of that string were then
1105 * {@link #insert(int,String) inserted} into this character
1106 * sequence at the indicated offset.
1107 * <p>
1108 * The {@code offset} argument must be greater than or equal to
1109 * {@code 0}, and less than or equal to the {@linkplain #length() length}
1110 * of this sequence.
1111 *
1112 * @param offset the offset.
1113 * @param obj an {@code Object}.
1114 * @return a reference to this object.
1115 * @throws StringIndexOutOfBoundsException if the offset is invalid.
1116 */
1117 public AbstractStringBuilder insert(int offset, Object obj) {
1118 return insert(offset, String.valueOf(obj));
1119 }
1120
1121 /**
1122 * Inserts the string into this character sequence.
1123 * <p>
1124 * The characters of the {@code String} argument are inserted, in
1125 * order, into this sequence at the indicated offset, moving up any
1126 * characters originally above that position and increasing the length
1127 * of this sequence by the length of the argument. If
1128 * {@code str} is {@code null}, then the four characters
1129 * {@code "null"} are inserted into this sequence.
1130 * <p>
1131 * The character at index <i>k</i> in the new character sequence is
1132 * equal to:
1133 * <ul>
1134 * <li>the character at index <i>k</i> in the old character sequence, if
1135 * <i>k</i> is less than {@code offset}
1136 * <li>the character at index <i>k</i>{@code -offset} in the
1137 * argument {@code str}, if <i>k</i> is not less than
1138 * {@code offset} but is less than {@code offset+str.length()}
1139 * <li>the character at index <i>k</i>{@code -str.length()} in the
1140 * old character sequence, if <i>k</i> is not less than
1141 * {@code offset+str.length()}
1142 * </ul><p>
1143 * The {@code offset} argument must be greater than or equal to
1144 * {@code 0}, and less than or equal to the {@linkplain #length() length}
1145 * of this sequence.
1146 *
1147 * @param offset the offset.
1148 * @param str a string.
1149 * @return a reference to this object.
1150 * @throws StringIndexOutOfBoundsException if the offset is invalid.
1151 */
1152 public AbstractStringBuilder insert(int offset, String str) {
1153 checkOffset(offset, count);
1154 if (str == null) {
1155 str = "null";
1156 }
1157 int len = str.length();
1158 ensureCapacityInternal(count + len);
1159 shift(offset, len);
1160 count += len;
1161 putStringAt(offset, str);
1162 return this;
1163 }
1164
1165 /**
1166 * Inserts the string representation of the {@code char} array
1167 * argument into this sequence.
1168 * <p>
1169 * The characters of the array argument are inserted into the
1170 * contents of this sequence at the position indicated by
1171 * {@code offset}. The length of this sequence increases by
1172 * the length of the argument.
1173 * <p>
1174 * The overall effect is exactly as if the second argument were
1175 * converted to a string by the method {@link String#valueOf(char[])},
1176 * and the characters of that string were then
1177 * {@link #insert(int,String) inserted} into this character
1178 * sequence at the indicated offset.
1179 * <p>
1180 * The {@code offset} argument must be greater than or equal to
1181 * {@code 0}, and less than or equal to the {@linkplain #length() length}
1182 * of this sequence.
1183 *
1184 * @param offset the offset.
1185 * @param str a character array.
1186 * @return a reference to this object.
1187 * @throws StringIndexOutOfBoundsException if the offset is invalid.
1188 */
1189 public AbstractStringBuilder insert(int offset, char[] str) {
1190 checkOffset(offset, count);
1191 int len = str.length;
1192 ensureCapacityInternal(count + len);
1193 shift(offset, len);
1194 count += len;
1195 putCharsAt(offset, str, 0, len);
1196 return this;
1197 }
1198
1199 /**
1200 * Inserts the specified {@code CharSequence} into this sequence.
1201 * <p>
1202 * The characters of the {@code CharSequence} argument are inserted,
1203 * in order, into this sequence at the indicated offset, moving up
1204 * any characters originally above that position and increasing the length
1205 * of this sequence by the length of the argument s.
1206 * <p>
1207 * The result of this method is exactly the same as if it were an
1208 * invocation of this object's
1209 * {@link #insert(int,CharSequence,int,int) insert}(dstOffset, s, 0, s.length())
1210 * method.
1211 *
1212 * <p>If {@code s} is {@code null}, then the four characters
1213 * {@code "null"} are inserted into this sequence.
1214 *
1215 * @param dstOffset the offset.
1216 * @param s the sequence to be inserted
1217 * @return a reference to this object.
1218 * @throws IndexOutOfBoundsException if the offset is invalid.
1219 */
1220 public AbstractStringBuilder insert(int dstOffset, CharSequence s) {
1221 if (s == null) {
1222 s = "null";
1223 }
1224 if (s instanceof String) {
1225 return this.insert(dstOffset, (String)s);
1226 }
1227 return this.insert(dstOffset, s, 0, s.length());
1228 }
1229
1230 /**
1231 * Inserts a subsequence of the specified {@code CharSequence} into
1232 * this sequence.
1233 * <p>
1234 * The subsequence of the argument {@code s} specified by
1235 * {@code start} and {@code end} are inserted,
1236 * in order, into this sequence at the specified destination offset, moving
1237 * up any characters originally above that position. The length of this
1238 * sequence is increased by {@code end - start}.
1239 * <p>
1240 * The character at index <i>k</i> in this sequence becomes equal to:
1241 * <ul>
1242 * <li>the character at index <i>k</i> in this sequence, if
1243 * <i>k</i> is less than {@code dstOffset}
1244 * <li>the character at index <i>k</i>{@code +start-dstOffset} in
1245 * the argument {@code s}, if <i>k</i> is greater than or equal to
1246 * {@code dstOffset} but is less than {@code dstOffset+end-start}
1247 * <li>the character at index <i>k</i>{@code -(end-start)} in this
1248 * sequence, if <i>k</i> is greater than or equal to
1249 * {@code dstOffset+end-start}
1250 * </ul><p>
1251 * The {@code dstOffset} argument must be greater than or equal to
1252 * {@code 0}, and less than or equal to the {@linkplain #length() length}
1253 * of this sequence.
1254 * <p>The start argument must be nonnegative, and not greater than
1255 * {@code end}.
1256 * <p>The end argument must be greater than or equal to
1257 * {@code start}, and less than or equal to the length of s.
1258 *
1259 * <p>If {@code s} is {@code null}, then this method inserts
1260 * characters as if the s parameter was a sequence containing the four
1261 * characters {@code "null"}.
1262 *
1263 * @param dstOffset the offset in this sequence.
1264 * @param s the sequence to be inserted.
1265 * @param start the starting index of the subsequence to be inserted.
1266 * @param end the end index of the subsequence to be inserted.
1267 * @return a reference to this object.
1268 * @throws IndexOutOfBoundsException if {@code dstOffset}
1269 * is negative or greater than {@code this.length()}, or
1270 * {@code start} or {@code end} are negative, or
1271 * {@code start} is greater than {@code end} or
1272 * {@code end} is greater than {@code s.length()}
1273 */
1274 public AbstractStringBuilder insert(int dstOffset, CharSequence s,
1275 int start, int end)
1276 {
1277 if (s == null) {
1278 s = "null";
1279 }
1280 checkOffset(dstOffset, count);
1281 checkRange(start, end, s.length());
1282 int len = end - start;
1283 ensureCapacityInternal(count + len);
1284 shift(dstOffset, len);
1285 count += len;
1286 putCharsAt(dstOffset, s, start, end);
1287 return this;
1288 }
1289
1290 /**
1291 * Inserts the string representation of the {@code boolean}
1292 * argument into this sequence.
1293 * <p>
1294 * The overall effect is exactly as if the second argument were
1295 * converted to a string by the method {@link String#valueOf(boolean)},
1296 * and the characters of that string were then
1297 * {@link #insert(int,String) inserted} into this character
1298 * sequence at the indicated offset.
1299 * <p>
1300 * The {@code offset} argument must be greater than or equal to
1301 * {@code 0}, and less than or equal to the {@linkplain #length() length}
1302 * of this sequence.
1303 *
1304 * @param offset the offset.
1305 * @param b a {@code boolean}.
1306 * @return a reference to this object.
1307 * @throws StringIndexOutOfBoundsException if the offset is invalid.
1308 */
1309 public AbstractStringBuilder insert(int offset, boolean b) {
1310 return insert(offset, String.valueOf(b));
1311 }
1312
1313 /**
1314 * Inserts the string representation of the {@code char}
1315 * argument into this sequence.
1316 * <p>
1317 * The overall effect is exactly as if the second argument were
1318 * converted to a string by the method {@link String#valueOf(char)},
1319 * and the character in that string were then
1320 * {@link #insert(int,String) inserted} into this character
1321 * sequence at the indicated offset.
1322 * <p>
1323 * The {@code offset} argument must be greater than or equal to
1324 * {@code 0}, and less than or equal to the {@linkplain #length() length}
1325 * of this sequence.
1326 *
1327 * @param offset the offset.
1328 * @param c a {@code char}.
1329 * @return a reference to this object.
1330 * @throws IndexOutOfBoundsException if the offset is invalid.
1331 */
1332 public AbstractStringBuilder insert(int offset, char c) {
1333 checkOffset(offset, count);
1334 ensureCapacityInternal(count + 1);
1335 shift(offset, 1);
1336 count += 1;
1337 if (isLatin1() && StringLatin1.canEncode(c)) {
1338 value[offset] = (byte)c;
1339 } else {
1340 if (isLatin1()) {
1341 inflate();
1342 }
1343 StringUTF16.putCharSB(value, offset, c);
1344 }
1345 return this;
1346 }
1347
1348 /**
1349 * Inserts the string representation of the second {@code int}
1350 * argument into this sequence.
1351 * <p>
1352 * The overall effect is exactly as if the second argument were
1353 * converted to a string by the method {@link String#valueOf(int)},
1354 * and the characters of that string were then
1355 * {@link #insert(int,String) inserted} into this character
1356 * sequence at the indicated offset.
1357 * <p>
1358 * The {@code offset} argument must be greater than or equal to
1359 * {@code 0}, and less than or equal to the {@linkplain #length() length}
1360 * of this sequence.
1361 *
1362 * @param offset the offset.
1363 * @param i an {@code int}.
1364 * @return a reference to this object.
1365 * @throws StringIndexOutOfBoundsException if the offset is invalid.
1366 */
1367 public AbstractStringBuilder insert(int offset, int i) {
1368 return insert(offset, String.valueOf(i));
1369 }
1370
1371 /**
1372 * Inserts the string representation of the {@code long}
1373 * argument into this sequence.
1374 * <p>
1375 * The overall effect is exactly as if the second argument were
1376 * converted to a string by the method {@link String#valueOf(long)},
1377 * and the characters of that string were then
1378 * {@link #insert(int,String) inserted} into this character
1379 * sequence at the indicated offset.
1380 * <p>
1381 * The {@code offset} argument must be greater than or equal to
1382 * {@code 0}, and less than or equal to the {@linkplain #length() length}
1383 * of this sequence.
1384 *
1385 * @param offset the offset.
1386 * @param l a {@code long}.
1387 * @return a reference to this object.
1388 * @throws StringIndexOutOfBoundsException if the offset is invalid.
1389 */
1390 public AbstractStringBuilder insert(int offset, long l) {
1391 return insert(offset, String.valueOf(l));
1392 }
1393
1394 /**
1395 * Inserts the string representation of the {@code float}
1396 * argument into this sequence.
1397 * <p>
1398 * The overall effect is exactly as if the second argument were
1399 * converted to a string by the method {@link String#valueOf(float)},
1400 * and the characters of that string were then
1401 * {@link #insert(int,String) inserted} into this character
1402 * sequence at the indicated offset.
1403 * <p>
1404 * The {@code offset} argument must be greater than or equal to
1405 * {@code 0}, and less than or equal to the {@linkplain #length() length}
1406 * of this sequence.
1407 *
1408 * @param offset the offset.
1409 * @param f a {@code float}.
1410 * @return a reference to this object.
1411 * @throws StringIndexOutOfBoundsException if the offset is invalid.
1412 */
1413 public AbstractStringBuilder insert(int offset, float f) {
1414 return insert(offset, String.valueOf(f));
1415 }
1416
1417 /**
1418 * Inserts the string representation of the {@code double}
1419 * argument into this sequence.
1420 * <p>
1421 * The overall effect is exactly as if the second argument were
1422 * converted to a string by the method {@link String#valueOf(double)},
1423 * and the characters of that string were then
1424 * {@link #insert(int,String) inserted} into this character
1425 * sequence at the indicated offset.
1426 * <p>
1427 * The {@code offset} argument must be greater than or equal to
1428 * {@code 0}, and less than or equal to the {@linkplain #length() length}
1429 * of this sequence.
1430 *
1431 * @param offset the offset.
1432 * @param d a {@code double}.
1433 * @return a reference to this object.
1434 * @throws StringIndexOutOfBoundsException if the offset is invalid.
1435 */
1436 public AbstractStringBuilder insert(int offset, double d) {
1437 return insert(offset, String.valueOf(d));
1438 }
1439
1440 /**
1441 * Returns the index within this string of the first occurrence of the
1442 * specified substring.
1443 *
1444 * <p>The returned index is the smallest value {@code k} for which:
1445 * <pre>{@code
1446 * this.toString().startsWith(str, k)
1447 * }</pre>
1448 * If no such value of {@code k} exists, then {@code -1} is returned.
1449 *
1450 * @param str the substring to search for.
1451 * @return the index of the first occurrence of the specified substring,
1452 * or {@code -1} if there is no such occurrence.
1453 */
1454 public int indexOf(String str) {
1455 return indexOf(str, 0);
1456 }
1457
1458 /**
1459 * Returns the index within this string of the first occurrence of the
1460 * specified substring, starting at the specified index.
1461 *
1462 * <p>The returned index is the smallest value {@code k} for which:
1463 * <pre>{@code
1464 * k >= Math.min(fromIndex, this.length()) &&
1465 * this.toString().startsWith(str, k)
1466 * }</pre>
1467 * If no such value of {@code k} exists, then {@code -1} is returned.
1468 *
1469 * @param str the substring to search for.
1470 * @param fromIndex the index from which to start the search.
1471 * @return the index of the first occurrence of the specified substring,
1472 * starting at the specified index,
1473 * or {@code -1} if there is no such occurrence.
1474 */
1475 public int indexOf(String str, int fromIndex) {
1476 return String.indexOf(value, coder, count, str, fromIndex);
1477 }
1478
1479 /**
1480 * Returns the index within this string of the last occurrence of the
1481 * specified substring. The last occurrence of the empty string "" is
1482 * considered to occur at the index value {@code this.length()}.
1483 *
1484 * <p>The returned index is the largest value {@code k} for which:
1485 * <pre>{@code
1486 * this.toString().startsWith(str, k)
1487 * }</pre>
1488 * If no such value of {@code k} exists, then {@code -1} is returned.
1489 *
1490 * @param str the substring to search for.
1491 * @return the index of the last occurrence of the specified substring,
1492 * or {@code -1} if there is no such occurrence.
1493 */
1494 public int lastIndexOf(String str) {
1495 return lastIndexOf(str, count);
1496 }
1497
1498 /**
1499 * Returns the index within this string of the last occurrence of the
1500 * specified substring, searching backward starting at the specified index.
1501 *
1502 * <p>The returned index is the largest value {@code k} for which:
1503 * <pre>{@code
1504 * k <= Math.min(fromIndex, this.length()) &&
1505 * this.toString().startsWith(str, k)
1506 * }</pre>
1507 * If no such value of {@code k} exists, then {@code -1} is returned.
1508 *
1509 * @param str the substring to search for.
1510 * @param fromIndex the index to start the search from.
1511 * @return the index of the last occurrence of the specified substring,
1512 * searching backward from the specified index,
1513 * or {@code -1} if there is no such occurrence.
1514 */
1515 public int lastIndexOf(String str, int fromIndex) {
1516 return String.lastIndexOf(value, coder, count, str, fromIndex);
1517 }
1518
1519 /**
1520 * Causes this character sequence to be replaced by the reverse of
1521 * the sequence. If there are any surrogate pairs included in the
1522 * sequence, these are treated as single characters for the
1523 * reverse operation. Thus, the order of the high-low surrogates
1524 * is never reversed.
1525 *
1526 * Let <i>n</i> be the character length of this character sequence
1527 * (not the length in {@code char} values) just prior to
1528 * execution of the {@code reverse} method. Then the
1529 * character at index <i>k</i> in the new character sequence is
1530 * equal to the character at index <i>n-k-1</i> in the old
1531 * character sequence.
1532 *
1533 * <p>Note that the reverse operation may result in producing
1534 * surrogate pairs that were unpaired low-surrogates and
1535 * high-surrogates before the operation. For example, reversing
1536 * "\u005CuDC00\u005CuD800" produces "\u005CuD800\u005CuDC00" which is
1537 * a valid surrogate pair.
1538 *
1539 * @return a reference to this object.
1540 */
1541 public AbstractStringBuilder reverse() {
1542 byte[] val = this.value;
1543 int count = this.count;
1544 int coder = this.coder;
1545 int n = count - 1;
1546 if (COMPACT_STRINGS && coder == LATIN1) {
1547 for (int j = (n-1) >> 1; j >= 0; j--) {
1548 int k = n - j;
1549 byte cj = val[j];
1550 val[j] = val[k];
1551 val[k] = cj;
1552 }
1553 } else {
1554 checkOffset(count, val.length >> 1);
1555 boolean hasSurrogates = false;
1556 for (int j = (n-1) >> 1; j >= 0; j--) {
1557 int k = n - j;
1558 char cj = StringUTF16.getChar(val, j);
1559 char ck = StringUTF16.getChar(val, k);
1560 StringUTF16.putChar(val, j, ck);
1561 StringUTF16.putChar(val, k, cj);
1562 if (Character.isSurrogate(cj) ||
1563 Character.isSurrogate(ck)) {
1564 hasSurrogates = true;
1565 }
1566 }
1567 if (hasSurrogates) {
1568 reverseAllValidSurrogatePairs(val, count);
1569 }
1570 }
1571 return this;
1572 }
1573
1574 /** Outlined helper method for reverse() */
1575 private void reverseAllValidSurrogatePairs(byte[] val, int count) {
1576 for (int i = 0; i < count - 1; i++) {
1577 char c2 = StringUTF16.getChar(val, i);
1578 if (Character.isLowSurrogate(c2)) {
1579 char c1 = StringUTF16.getChar(val, i + 1);
1580 if (Character.isHighSurrogate(c1)) {
1581 StringUTF16.putChar(val, i++, c1);
1582 StringUTF16.putChar(val, i, c2);
1583 }
1584 }
1585 }
1586 }
1587
1588 /**
1589 * Returns a string representing the data in this sequence.
1590 * A new {@code String} object is allocated and initialized to
1591 * contain the character sequence currently represented by this
1592 * object. This {@code String} is then returned. Subsequent
1593 * changes to this sequence do not affect the contents of the
1594 * {@code String}.
1595 *
1596 * @return a string representation of this sequence of characters.
1597 */
1598 @Override
1599 public abstract String toString();
1600
1601 /**
1602 * {@inheritDoc}
1603 * @since 9
1604 */
1605 @Override
1606 public IntStream chars() {
1607 // Reuse String-based spliterator. This requires a supplier to
1608 // capture the value and count when the terminal operation is executed
1609 return StreamSupport.intStream(
1610 () -> {
1611 // The combined set of field reads are not atomic and thread
1612 // safe but bounds checks will ensure no unsafe reads from
1613 // the byte array
1614 byte[] val = this.value;
1615 int count = this.count;
1616 byte coder = this.coder;
1617 return coder == LATIN1
1618 ? new StringLatin1.CharsSpliterator(val, 0, count, 0)
1619 : new StringUTF16.CharsSpliterator(val, 0, count, 0);
1620 },
1621 Spliterator.ORDERED | Spliterator.SIZED | Spliterator.SUBSIZED,
1622 false);
1623 }
1624
1625 /**
1626 * {@inheritDoc}
1627 * @since 9
1628 */
1629 @Override
1630 public IntStream codePoints() {
1631 // Reuse String-based spliterator. This requires a supplier to
1632 // capture the value and count when the terminal operation is executed
1633 return StreamSupport.intStream(
1634 () -> {
1635 // The combined set of field reads are not atomic and thread
1636 // safe but bounds checks will ensure no unsafe reads from
1637 // the byte array
1638 byte[] val = this.value;
1639 int count = this.count;
1640 byte coder = this.coder;
1641 return coder == LATIN1
1642 ? new StringLatin1.CharsSpliterator(val, 0, count, 0)
1643 : new StringUTF16.CodePointsSpliterator(val, 0, count, 0);
1644 },
1645 Spliterator.ORDERED,
1646 false);
1647 }
1648
1649 /**
1650 * Needed by {@code String} for the contentEquals method.
1651 */
1652 final byte[] getValue() {
1653 return value;
1654 }
1655
1656 /*
1657 * Invoker guarantees it is in UTF16 (inflate itself for asb), if two
1658 * coders are different and the dstBegin has enough space
1659 *
1660 * @param dstBegin the char index, not offset of byte[]
1661 * @param coder the coder of dst[]
1662 */
1663 void getBytes(byte dst[], int dstBegin, byte coder) {
1664 if (this.coder == coder) {
1665 System.arraycopy(value, 0, dst, dstBegin << coder, count << coder);
1666 } else { // this.coder == LATIN && coder == UTF16
1667 StringLatin1.inflate(value, 0, dst, dstBegin, count);
1668 }
1669 }
1670
1671 /* for readObject() */
1672 void initBytes(char[] value, int off, int len) {
1673 if (String.COMPACT_STRINGS) {
1674 this.value = StringUTF16.compress(value, off, len);
1675 if (this.value != null) {
1676 this.coder = LATIN1;
1677 return;
1678 }
1679 }
1680 this.coder = UTF16;
1681 this.value = StringUTF16.toBytes(value, off, len);
1682 }
1683
1684 final byte getCoder() {
1685 return COMPACT_STRINGS ? coder : UTF16;
1686 }
1687
1688 final boolean isLatin1() {
1689 return COMPACT_STRINGS && coder == LATIN1;
1690 }
1691
1692 private final void putCharsAt(int index, char[] s, int off, int end) {
1693 if (isLatin1()) {
1694 byte[] val = this.value;
1695 for (int i = off, j = index; i < end; i++) {
1696 char c = s[i];
1697 if (StringLatin1.canEncode(c)) {
1698 val[j++] = (byte)c;
1699 } else {
1700 inflate();
1701 StringUTF16.putCharsSB(this.value, j, s, i, end);
1702 return;
1703 }
1704 }
1705 } else {
1706 StringUTF16.putCharsSB(this.value, index, s, off, end);
1707 }
1708 }
1709
1710 private final void putCharsAt(int index, CharSequence s, int off, int end) {
1711 if (isLatin1()) {
1712 byte[] val = this.value;
1713 for (int i = off, j = index; i < end; i++) {
1714 char c = s.charAt(i);
1715 if (StringLatin1.canEncode(c)) {
1716 val[j++] = (byte)c;
1717 } else {
1718 inflate();
1719 StringUTF16.putCharsSB(this.value, j, s, i, end);
1720 return;
1721 }
1722 }
1723 } else {
1724 StringUTF16.putCharsSB(this.value, index, s, off, end);
1725 }
1726 }
1727
1728 private final void putStringAt(int index, String str) {
1729 if (getCoder() != str.coder()) {
1730 inflate();
1731 }
1732 str.getBytes(value, index, coder);
1733 }
1734
1735 private final void appendChars(char[] s, int off, int end) {
1736 if (isLatin1()) {
1737 byte[] val = this.value;
1738 for (int i = off, j = count; i < end; i++) {
1739 char c = s[i];
1740 if (StringLatin1.canEncode(c)) {
1741 val[j++] = (byte)c;
1742 } else {
1743 count = j;
1744 inflate();
1745 StringUTF16.putCharsSB(this.value, j, s, i, end);
1746 count += end - i;
1747 return;
1748 }
1749 }
1750 } else {
1751 StringUTF16.putCharsSB(this.value, count, s, off, end);
1752 }
1753 count += end - off;
1754 }
1755
1756 private final void appendChars(CharSequence s, int off, int end) {
1757 if (isLatin1()) {
1758 byte[] val = this.value;
1759 for (int i = off, j = count; i < end; i++) {
1760 char c = s.charAt(i);
1761 if (StringLatin1.canEncode(c)) {
1762 val[j++] = (byte)c;
1763 } else {
1764 count = j;
1765 inflate();
1766 StringUTF16.putCharsSB(this.value, j, s, i, end);
1767 count += end - i;
1768 return;
1769 }
1770 }
1771 } else {
1772 StringUTF16.putCharsSB(this.value, count, s, off, end);
1773 }
1774 count += end - off;
1775 }
1776
1777 /* IndexOutOfBoundsException, if out of bounds */
1778 private static void checkRange(int start, int end, int len) {
1779 if (start < 0 || start > end || end > len) {
1780 throw new IndexOutOfBoundsException(
1781 "start " + start + ", end " + end + ", length " + len);
1782 }
1783 }
1784
1785 /* StringIndexOutOfBoundsException, if out of bounds */
1786 private static void checkRangeSIOOBE(int start, int end, int len) {
1787 if (start < 0 || start > end || end > len) {
1788 throw new StringIndexOutOfBoundsException(
1789 "start " + start + ", end " + end + ", length " + len);
1790 }
1791 }
1792 }