1 /*
2 * Copyright (c) 1994, 2012, 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 java.io.ObjectStreamField;
29 import java.io.UnsupportedEncodingException;
30 import java.nio.charset.Charset;
31 import java.util.ArrayList;
32 import java.util.Arrays;
33 import java.util.Comparator;
34 import java.util.Formatter;
35 import java.util.Locale;
36 import java.util.Objects;
37 import java.util.regex.Matcher;
38 import java.util.regex.Pattern;
39 import java.util.regex.PatternSyntaxException;
40
41 /**
42 * The {@code String} class represents character strings. All
43 * string literals in Java programs, such as {@code "abc"}, are
44 * implemented as instances of this class.
45 * <p>
46 * Strings are constant; their values cannot be changed after they
47 * are created. String buffers support mutable strings.
48 * Because String objects are immutable they can be shared. For example:
49 * <p><blockquote><pre>
50 * String str = "abc";
51 * </pre></blockquote><p>
52 * is equivalent to:
53 * <p><blockquote><pre>
54 * char data[] = {'a', 'b', 'c'};
55 * String str = new String(data);
56 * </pre></blockquote><p>
57 * Here are some more examples of how strings can be used:
58 * <p><blockquote><pre>
59 * System.out.println("abc");
60 * String cde = "cde";
61 * System.out.println("abc" + cde);
62 * String c = "abc".substring(2,3);
63 * String d = cde.substring(1, 2);
64 * </pre></blockquote>
65 * <p>
66 * The class {@code String} includes methods for examining
67 * individual characters of the sequence, for comparing strings, for
68 * searching strings, for extracting substrings, and for creating a
69 * copy of a string with all characters translated to uppercase or to
70 * lowercase. Case mapping is based on the Unicode Standard version
71 * specified by the {@link java.lang.Character Character} class.
72 * <p>
73 * The Java language provides special support for the string
74 * concatenation operator ( + ), and for conversion of
75 * other objects to strings. String concatenation is implemented
76 * through the {@code StringBuilder}(or {@code StringBuffer})
77 * class and its {@code append} method.
78 * String conversions are implemented through the method
79 * {@code toString}, defined by {@code Object} and
80 * inherited by all classes in Java. For additional information on
81 * string concatenation and conversion, see Gosling, Joy, and Steele,
82 * <i>The Java Language Specification</i>.
83 *
84 * <p> Unless otherwise noted, passing a <tt>null</tt> argument to a constructor
85 * or method in this class will cause a {@link NullPointerException} to be
86 * thrown.
87 *
88 * <p>A {@code String} represents a string in the UTF-16 format
89 * in which <em>supplementary characters</em> are represented by <em>surrogate
90 * pairs</em> (see the section <a href="Character.html#unicode">Unicode
91 * Character Representations</a> in the {@code Character} class for
92 * more information).
93 * Index values refer to {@code char} code units, so a supplementary
94 * character uses two positions in a {@code String}.
95 * <p>The {@code String} class provides methods for dealing with
96 * Unicode code points (i.e., characters), in addition to those for
97 * dealing with Unicode code units (i.e., {@code char} values).
98 *
99 * @author Lee Boynton
100 * @author Arthur van Hoff
101 * @author Martin Buchholz
102 * @author Ulf Zibis
103 * @see java.lang.Object#toString()
104 * @see java.lang.StringBuffer
105 * @see java.lang.StringBuilder
106 * @see java.nio.charset.Charset
107 * @since JDK1.0
108 */
109
110 public final class String
111 implements java.io.Serializable, Comparable<String>, CharSequence {
112 /** The value is used for character storage. */
113 private final char value[];
114
115 /** Cache the hash code for the string */
116 private int hash; // Default to 0
117
118 /** use serialVersionUID from JDK 1.0.2 for interoperability */
119 private static final long serialVersionUID = -6849794470754667710L;
120
121 /**
122 * Class String is special cased within the Serialization Stream Protocol.
123 *
124 * A String instance is written initially into an ObjectOutputStream in the
125 * following format:
126 * <pre>
127 * {@code TC_STRING} (utf String)
128 * </pre>
129 * The String is written by method {@code DataOutput.writeUTF}.
130 * A new handle is generated to refer to all future references to the
131 * string instance within the stream.
132 */
133 private static final ObjectStreamField[] serialPersistentFields =
134 new ObjectStreamField[0];
135
136 /**
137 * Initializes a newly created {@code String} object so that it represents
138 * an empty character sequence. Note that use of this constructor is
139 * unnecessary since Strings are immutable.
140 */
141 public String() {
142 this.value = new char[0];
143 }
144
145 /**
146 * Initializes a newly created {@code String} object so that it represents
147 * the same sequence of characters as the argument; in other words, the
148 * newly created string is a copy of the argument string. Unless an
149 * explicit copy of {@code original} is needed, use of this constructor is
150 * unnecessary since Strings are immutable.
151 *
152 * @param original
153 * A {@code String}
154 */
155 public String(String original) {
156 this.value = original.value;
157 this.hash = original.hash;
158 }
159
160 /**
161 * Allocates a new {@code String} so that it represents the sequence of
162 * characters currently contained in the character array argument. The
163 * contents of the character array are copied; subsequent modification of
164 * the character array does not affect the newly created string.
165 *
166 * @param value
167 * The initial value of the string
168 */
169 public String(char value[]) {
170 this.value = Arrays.copyOf(value, value.length);
171 }
172
173 /**
174 * Allocates a new {@code String} that contains characters from a subarray
175 * of the character array argument. The {@code offset} argument is the
176 * index of the first character of the subarray and the {@code count}
177 * argument specifies the length of the subarray. The contents of the
178 * subarray are copied; subsequent modification of the character array does
179 * not affect the newly created string.
180 *
181 * @param value
182 * Array that is the source of characters
183 *
184 * @param offset
185 * The initial offset
186 *
187 * @param count
188 * The length
189 *
190 * @throws IndexOutOfBoundsException
191 * If the {@code offset} and {@code count} arguments index
192 * characters outside the bounds of the {@code value} array
193 */
194 public String(char value[], int offset, int count) {
195 if (offset < 0) {
196 throw new StringIndexOutOfBoundsException(offset);
197 }
198 if (count < 0) {
199 throw new StringIndexOutOfBoundsException(count);
200 }
201 // Note: offset or count might be near -1>>>1.
202 if (offset > value.length - count) {
203 throw new StringIndexOutOfBoundsException(offset + count);
204 }
205 this.value = Arrays.copyOfRange(value, offset, offset+count);
206 }
207
208 /**
209 * Allocates a new {@code String} that contains characters from a subarray
210 * of the <a href="Character.html#unicode">Unicode code point</a> array
211 * argument. The {@code offset} argument is the index of the first code
212 * point of the subarray and the {@code count} argument specifies the
213 * length of the subarray. The contents of the subarray are converted to
214 * {@code char}s; subsequent modification of the {@code int} array does not
215 * affect the newly created string.
216 *
217 * @param codePoints
218 * Array that is the source of Unicode code points
219 *
220 * @param offset
221 * The initial offset
222 *
223 * @param count
224 * The length
225 *
226 * @throws IllegalArgumentException
227 * If any invalid Unicode code point is found in {@code
228 * codePoints}
229 *
230 * @throws IndexOutOfBoundsException
231 * If the {@code offset} and {@code count} arguments index
232 * characters outside the bounds of the {@code codePoints} array
233 *
234 * @since 1.5
235 */
236 public String(int[] codePoints, int offset, int count) {
237 if (offset < 0) {
238 throw new StringIndexOutOfBoundsException(offset);
239 }
240 if (count < 0) {
241 throw new StringIndexOutOfBoundsException(count);
242 }
243 // Note: offset or count might be near -1>>>1.
244 if (offset > codePoints.length - count) {
245 throw new StringIndexOutOfBoundsException(offset + count);
246 }
247
248 final int end = offset + count;
249
250 // Pass 1: Compute precise size of char[]
251 int n = count;
252 for (int i = offset; i < end; i++) {
253 int c = codePoints[i];
254 if (Character.isBmpCodePoint(c))
255 continue;
256 else if (Character.isValidCodePoint(c))
257 n++;
258 else throw new IllegalArgumentException(Integer.toString(c));
259 }
260
261 // Pass 2: Allocate and fill in char[]
262 final char[] v = new char[n];
263
264 for (int i = offset, j = 0; i < end; i++, j++) {
265 int c = codePoints[i];
266 if (Character.isBmpCodePoint(c))
267 v[j] = (char)c;
268 else
269 Character.toSurrogates(c, v, j++);
270 }
271
272 this.value = v;
273 }
274
275 /**
276 * Allocates a new {@code String} constructed from a subarray of an array
277 * of 8-bit integer values.
278 *
279 * <p> The {@code offset} argument is the index of the first byte of the
280 * subarray, and the {@code count} argument specifies the length of the
281 * subarray.
282 *
283 * <p> Each {@code byte} in the subarray is converted to a {@code char} as
284 * specified in the method above.
285 *
286 * @deprecated This method does not properly convert bytes into characters.
287 * As of JDK 1.1, the preferred way to do this is via the
288 * {@code String} constructors that take a {@link
289 * java.nio.charset.Charset}, charset name, or that use the platform's
290 * default charset.
291 *
292 * @param ascii
293 * The bytes to be converted to characters
294 *
295 * @param hibyte
296 * The top 8 bits of each 16-bit Unicode code unit
297 *
298 * @param offset
299 * The initial offset
300 * @param count
301 * The length
302 *
303 * @throws IndexOutOfBoundsException
304 * If the {@code offset} or {@code count} argument is invalid
305 *
306 * @see #String(byte[], int)
307 * @see #String(byte[], int, int, java.lang.String)
308 * @see #String(byte[], int, int, java.nio.charset.Charset)
309 * @see #String(byte[], int, int)
310 * @see #String(byte[], java.lang.String)
311 * @see #String(byte[], java.nio.charset.Charset)
312 * @see #String(byte[])
313 */
314 @Deprecated
315 public String(byte ascii[], int hibyte, int offset, int count) {
316 checkBounds(ascii, offset, count);
317 char value[] = new char[count];
318
319 if (hibyte == 0) {
320 for (int i = count; i-- > 0;) {
321 value[i] = (char)(ascii[i + offset] & 0xff);
322 }
323 } else {
324 hibyte <<= 8;
325 for (int i = count; i-- > 0;) {
326 value[i] = (char)(hibyte | (ascii[i + offset] & 0xff));
327 }
328 }
329 this.value = value;
330 }
331
332 /**
333 * Allocates a new {@code String} containing characters constructed from
334 * an array of 8-bit integer values. Each character <i>c</i>in the
335 * resulting string is constructed from the corresponding component
336 * <i>b</i> in the byte array such that:
337 *
338 * <blockquote><pre>
339 * <b><i>c</i></b> == (char)(((hibyte & 0xff) << 8)
340 * | (<b><i>b</i></b> & 0xff))
341 * </pre></blockquote>
342 *
343 * @deprecated This method does not properly convert bytes into
344 * characters. As of JDK 1.1, the preferred way to do this is via the
345 * {@code String} constructors that take a {@link
346 * java.nio.charset.Charset}, charset name, or that use the platform's
347 * default charset.
348 *
349 * @param ascii
350 * The bytes to be converted to characters
351 *
352 * @param hibyte
353 * The top 8 bits of each 16-bit Unicode code unit
354 *
355 * @see #String(byte[], int, int, java.lang.String)
356 * @see #String(byte[], int, int, java.nio.charset.Charset)
357 * @see #String(byte[], int, int)
358 * @see #String(byte[], java.lang.String)
359 * @see #String(byte[], java.nio.charset.Charset)
360 * @see #String(byte[])
361 */
362 @Deprecated
363 public String(byte ascii[], int hibyte) {
364 this(ascii, hibyte, 0, ascii.length);
365 }
366
367 /* Common private utility method used to bounds check the byte array
368 * and requested offset & length values used by the String(byte[],..)
369 * constructors.
370 */
371 private static void checkBounds(byte[] bytes, int offset, int length) {
372 if (length < 0)
373 throw new StringIndexOutOfBoundsException(length);
374 if (offset < 0)
375 throw new StringIndexOutOfBoundsException(offset);
376 if (offset > bytes.length - length)
377 throw new StringIndexOutOfBoundsException(offset + length);
378 }
379
380 /**
381 * Constructs a new {@code String} by decoding the specified subarray of
382 * bytes using the specified charset. The length of the new {@code String}
383 * is a function of the charset, and hence may not be equal to the length
384 * of the subarray.
385 *
386 * <p> The behavior of this constructor when the given bytes are not valid
387 * in the given charset is unspecified. The {@link
388 * java.nio.charset.CharsetDecoder} class should be used when more control
389 * over the decoding process is required.
390 *
391 * @param bytes
392 * The bytes to be decoded into characters
393 *
394 * @param offset
395 * The index of the first byte to decode
396 *
397 * @param length
398 * The number of bytes to decode
399
400 * @param charsetName
401 * The name of a supported {@linkplain java.nio.charset.Charset
402 * charset}
403 *
404 * @throws UnsupportedEncodingException
405 * If the named charset is not supported
406 *
407 * @throws IndexOutOfBoundsException
408 * If the {@code offset} and {@code length} arguments index
409 * characters outside the bounds of the {@code bytes} array
410 *
411 * @since JDK1.1
412 */
413 public String(byte bytes[], int offset, int length, String charsetName)
414 throws UnsupportedEncodingException {
415 if (charsetName == null)
416 throw new NullPointerException("charsetName");
417 checkBounds(bytes, offset, length);
418 this.value = StringCoding.decode(charsetName, bytes, offset, length);
419 }
420
421 /**
422 * Constructs a new {@code String} by decoding the specified subarray of
423 * bytes using the specified {@linkplain java.nio.charset.Charset charset}.
424 * The length of the new {@code String} is a function of the charset, and
425 * hence may not be equal to the length of the subarray.
426 *
427 * <p> This method always replaces malformed-input and unmappable-character
428 * sequences with this charset's default replacement string. The {@link
429 * java.nio.charset.CharsetDecoder} class should be used when more control
430 * over the decoding process is required.
431 *
432 * @param bytes
433 * The bytes to be decoded into characters
434 *
435 * @param offset
436 * The index of the first byte to decode
437 *
438 * @param length
439 * The number of bytes to decode
440 *
441 * @param charset
442 * The {@linkplain java.nio.charset.Charset charset} to be used to
443 * decode the {@code bytes}
444 *
445 * @throws IndexOutOfBoundsException
446 * If the {@code offset} and {@code length} arguments index
447 * characters outside the bounds of the {@code bytes} array
448 *
449 * @since 1.6
450 */
451 public String(byte bytes[], int offset, int length, Charset charset) {
452 if (charset == null)
453 throw new NullPointerException("charset");
454 checkBounds(bytes, offset, length);
455 this.value = StringCoding.decode(charset, bytes, offset, length);
456 }
457
458 /**
459 * Constructs a new {@code String} by decoding the specified array of bytes
460 * using the specified {@linkplain java.nio.charset.Charset charset}. The
461 * length of the new {@code String} is a function of the charset, and hence
462 * may not be equal to the length of the byte array.
463 *
464 * <p> The behavior of this constructor when the given bytes are not valid
465 * in the given charset is unspecified. The {@link
466 * java.nio.charset.CharsetDecoder} class should be used when more control
467 * over the decoding process is required.
468 *
469 * @param bytes
470 * The bytes to be decoded into characters
471 *
472 * @param charsetName
473 * The name of a supported {@linkplain java.nio.charset.Charset
474 * charset}
475 *
476 * @throws UnsupportedEncodingException
477 * If the named charset is not supported
478 *
479 * @since JDK1.1
480 */
481 public String(byte bytes[], String charsetName)
482 throws UnsupportedEncodingException {
483 this(bytes, 0, bytes.length, charsetName);
484 }
485
486 /**
487 * Constructs a new {@code String} by decoding the specified array of
488 * bytes using the specified {@linkplain java.nio.charset.Charset charset}.
489 * The length of the new {@code String} is a function of the charset, and
490 * hence may not be equal to the length of the byte array.
491 *
492 * <p> This method always replaces malformed-input and unmappable-character
493 * sequences with this charset's default replacement string. The {@link
494 * java.nio.charset.CharsetDecoder} class should be used when more control
495 * over the decoding process is required.
496 *
497 * @param bytes
498 * The bytes to be decoded into characters
499 *
500 * @param charset
501 * The {@linkplain java.nio.charset.Charset charset} to be used to
502 * decode the {@code bytes}
503 *
504 * @since 1.6
505 */
506 public String(byte bytes[], Charset charset) {
507 this(bytes, 0, bytes.length, charset);
508 }
509
510 /**
511 * Constructs a new {@code String} by decoding the specified subarray of
512 * bytes using the platform's default charset. The length of the new
513 * {@code String} is a function of the charset, and hence may not be equal
514 * to the length of the subarray.
515 *
516 * <p> The behavior of this constructor when the given bytes are not valid
517 * in the default charset is unspecified. The {@link
518 * java.nio.charset.CharsetDecoder} class should be used when more control
519 * over the decoding process is required.
520 *
521 * @param bytes
522 * The bytes to be decoded into characters
523 *
524 * @param offset
525 * The index of the first byte to decode
526 *
527 * @param length
528 * The number of bytes to decode
529 *
530 * @throws IndexOutOfBoundsException
531 * If the {@code offset} and the {@code length} arguments index
532 * characters outside the bounds of the {@code bytes} array
533 *
534 * @since JDK1.1
535 */
536 public String(byte bytes[], int offset, int length) {
537 checkBounds(bytes, offset, length);
538 this.value = StringCoding.decode(bytes, offset, length);
539 }
540
541 /**
542 * Constructs a new {@code String} by decoding the specified array of bytes
543 * using the platform's default charset. The length of the new {@code
544 * String} is a function of the charset, and hence may not be equal to the
545 * length of the byte array.
546 *
547 * <p> The behavior of this constructor when the given bytes are not valid
548 * in the default charset is unspecified. The {@link
549 * java.nio.charset.CharsetDecoder} class should be used when more control
550 * over the decoding process is required.
551 *
552 * @param bytes
553 * The bytes to be decoded into characters
554 *
555 * @since JDK1.1
556 */
557 public String(byte bytes[]) {
558 this(bytes, 0, bytes.length);
559 }
560
561 /**
562 * Allocates a new string that contains the sequence of characters
563 * currently contained in the string buffer argument. The contents of the
564 * string buffer are copied; subsequent modification of the string buffer
565 * does not affect the newly created string.
566 *
567 * @param buffer
568 * A {@code StringBuffer}
569 */
570 public String(StringBuffer buffer) {
571 synchronized(buffer) {
572 this.value = Arrays.copyOf(buffer.getValue(), buffer.length());
573 }
574 }
575
576 /**
577 * Allocates a new string that contains the sequence of characters
578 * currently contained in the string builder argument. The contents of the
579 * string builder are copied; subsequent modification of the string builder
580 * does not affect the newly created string.
581 *
582 * <p> This constructor is provided to ease migration to {@code
583 * StringBuilder}. Obtaining a string from a string builder via the {@code
584 * toString} method is likely to run faster and is generally preferred.
585 *
586 * @param builder
587 * A {@code StringBuilder}
588 *
589 * @since 1.5
590 */
591 public String(StringBuilder builder) {
592 this.value = Arrays.copyOf(builder.getValue(), builder.length());
593 }
594
595 /*
596 * Package private constructor which shares value array for speed.
597 * this constructor is always expected to be called with share==true.
598 * a separate constructor is needed because we already have a public
599 * String(char[]) constructor that makes a copy of the given char[].
600 */
601 String(char[] value, boolean share) {
602 // assert share : "unshared not supported";
603 this.value = value;
604 }
605
606 /**
607 * Returns the length of this string.
608 * The length is equal to the number of <a href="Character.html#unicode">Unicode
609 * code units</a> in the string.
610 *
611 * @return the length of the sequence of characters represented by this
612 * object.
613 */
614 public int length() {
615 return value.length;
616 }
617
618 /**
619 * Returns {@code true} if, and only if, {@link #length()} is {@code 0}.
620 *
621 * @return {@code true} if {@link #length()} is {@code 0}, otherwise
622 * {@code false}
623 *
624 * @since 1.6
625 */
626 public boolean isEmpty() {
627 return value.length == 0;
628 }
629
630 /**
631 * Returns the {@code char} value at the
632 * specified index. An index ranges from {@code 0} to
633 * {@code length() - 1}. The first {@code char} value of the sequence
634 * is at index {@code 0}, the next at index {@code 1},
635 * and so on, as for array indexing.
636 *
637 * <p>If the {@code char} value specified by the index is a
638 * <a href="Character.html#unicode">surrogate</a>, the surrogate
639 * value is returned.
640 *
641 * @param index the index of the {@code char} value.
642 * @return the {@code char} value at the specified index of this string.
643 * The first {@code char} value is at index {@code 0}.
644 * @exception IndexOutOfBoundsException if the {@code index}
645 * argument is negative or not less than the length of this
646 * string.
647 */
648 public char charAt(int index) {
649 if ((index < 0) || (index >= value.length)) {
650 throw new StringIndexOutOfBoundsException(index);
651 }
652 return value[index];
653 }
654
655 /**
656 * Returns the character (Unicode code point) at the specified
657 * index. The index refers to {@code char} values
658 * (Unicode code units) and ranges from {@code 0} to
659 * {@link #length()}{@code - 1}.
660 *
661 * <p> If the {@code char} value specified at the given index
662 * is in the high-surrogate range, the following index is less
663 * than the length of this {@code String}, and the
664 * {@code char} value at the following index is in the
665 * low-surrogate range, then the supplementary code point
666 * corresponding to this surrogate pair is returned. Otherwise,
667 * the {@code char} value at the given index is returned.
668 *
669 * @param index the index to the {@code char} values
670 * @return the code point value of the character at the
671 * {@code index}
672 * @exception IndexOutOfBoundsException if the {@code index}
673 * argument is negative or not less than the length of this
674 * string.
675 * @since 1.5
676 */
677 public int codePointAt(int index) {
678 if ((index < 0) || (index >= value.length)) {
679 throw new StringIndexOutOfBoundsException(index);
680 }
681 return Character.codePointAtImpl(value, index, value.length);
682 }
683
684 /**
685 * Returns the character (Unicode code point) before the specified
686 * index. The index refers to {@code char} values
687 * (Unicode code units) and ranges from {@code 1} to {@link
688 * CharSequence#length() length}.
689 *
690 * <p> If the {@code char} value at {@code (index - 1)}
691 * is in the low-surrogate range, {@code (index - 2)} is not
692 * negative, and the {@code char} value at {@code (index -
693 * 2)} is in the high-surrogate range, then the
694 * supplementary code point value of the surrogate pair is
695 * returned. If the {@code char} value at {@code index -
696 * 1} is an unpaired low-surrogate or a high-surrogate, the
697 * surrogate value is returned.
698 *
699 * @param index the index following the code point that should be returned
700 * @return the Unicode code point value before the given index.
701 * @exception IndexOutOfBoundsException if the {@code index}
702 * argument is less than 1 or greater than the length
703 * of this string.
704 * @since 1.5
705 */
706 public int codePointBefore(int index) {
707 int i = index - 1;
708 if ((i < 0) || (i >= value.length)) {
709 throw new StringIndexOutOfBoundsException(index);
710 }
711 return Character.codePointBeforeImpl(value, index, 0);
712 }
713
714 /**
715 * Returns the number of Unicode code points in the specified text
716 * range of this {@code String}. The text range begins at the
717 * specified {@code beginIndex} and extends to the
718 * {@code char} at index {@code endIndex - 1}. Thus the
719 * length (in {@code char}s) of the text range is
720 * {@code endIndex-beginIndex}. Unpaired surrogates within
721 * the text range count as one code point each.
722 *
723 * @param beginIndex the index to the first {@code char} of
724 * the text range.
725 * @param endIndex the index after the last {@code char} of
726 * the text range.
727 * @return the number of Unicode code points in the specified text
728 * range
729 * @exception IndexOutOfBoundsException if the
730 * {@code beginIndex} is negative, or {@code endIndex}
731 * is larger than the length of this {@code String}, or
732 * {@code beginIndex} is larger than {@code endIndex}.
733 * @since 1.5
734 */
735 public int codePointCount(int beginIndex, int endIndex) {
736 if (beginIndex < 0 || endIndex > value.length || beginIndex > endIndex) {
737 throw new IndexOutOfBoundsException();
738 }
739 return Character.codePointCountImpl(value, beginIndex, endIndex - beginIndex);
740 }
741
742 /**
743 * Returns the index within this {@code String} that is
744 * offset from the given {@code index} by
745 * {@code codePointOffset} code points. Unpaired surrogates
746 * within the text range given by {@code index} and
747 * {@code codePointOffset} count as one code point each.
748 *
749 * @param index the index to be offset
750 * @param codePointOffset the offset in code points
751 * @return the index within this {@code String}
752 * @exception IndexOutOfBoundsException if {@code index}
753 * is negative or larger then the length of this
754 * {@code String}, or if {@code codePointOffset} is positive
755 * and the substring starting with {@code index} has fewer
756 * than {@code codePointOffset} code points,
757 * or if {@code codePointOffset} is negative and the substring
758 * before {@code index} has fewer than the absolute value
759 * of {@code codePointOffset} code points.
760 * @since 1.5
761 */
762 public int offsetByCodePoints(int index, int codePointOffset) {
763 if (index < 0 || index > value.length) {
764 throw new IndexOutOfBoundsException();
765 }
766 return Character.offsetByCodePointsImpl(value, 0, value.length,
767 index, codePointOffset);
768 }
769
770 /**
771 * Copy characters from this string into dst starting at dstBegin.
772 * This method doesn't perform any range checking.
773 */
774 void getChars(char dst[], int dstBegin) {
775 System.arraycopy(value, 0, dst, dstBegin, value.length);
776 }
777
778 /**
779 * Copies characters from this string into the destination character
780 * array.
781 * <p>
782 * The first character to be copied is at index {@code srcBegin};
783 * the last character to be copied is at index {@code srcEnd-1}
784 * (thus the total number of characters to be copied is
785 * {@code srcEnd-srcBegin}). The characters are copied into the
786 * subarray of {@code dst} starting at index {@code dstBegin}
787 * and ending at index:
788 * <p><blockquote><pre>
789 * dstbegin + (srcEnd-srcBegin) - 1
790 * </pre></blockquote>
791 *
792 * @param srcBegin index of the first character in the string
793 * to copy.
794 * @param srcEnd index after the last character in the string
795 * to copy.
796 * @param dst the destination array.
797 * @param dstBegin the start offset in the destination array.
798 * @exception IndexOutOfBoundsException If any of the following
799 * is true:
800 * <ul><li>{@code srcBegin} is negative.
801 * <li>{@code srcBegin} is greater than {@code srcEnd}
802 * <li>{@code srcEnd} is greater than the length of this
803 * string
804 * <li>{@code dstBegin} is negative
805 * <li>{@code dstBegin+(srcEnd-srcBegin)} is larger than
806 * {@code dst.length}</ul>
807 */
808 public void getChars(int srcBegin, int srcEnd, char dst[], int dstBegin) {
809 if (srcBegin < 0) {
810 throw new StringIndexOutOfBoundsException(srcBegin);
811 }
812 if (srcEnd > value.length) {
813 throw new StringIndexOutOfBoundsException(srcEnd);
814 }
815 if (srcBegin > srcEnd) {
816 throw new StringIndexOutOfBoundsException(srcEnd - srcBegin);
817 }
818 System.arraycopy(value, srcBegin, dst, dstBegin, srcEnd - srcBegin);
819 }
820
821 /**
822 * Copies characters from this string into the destination byte array. Each
823 * byte receives the 8 low-order bits of the corresponding character. The
824 * eight high-order bits of each character are not copied and do not
825 * participate in the transfer in any way.
826 *
827 * <p> The first character to be copied is at index {@code srcBegin}; the
828 * last character to be copied is at index {@code srcEnd-1}. The total
829 * number of characters to be copied is {@code srcEnd-srcBegin}. The
830 * characters, converted to bytes, are copied into the subarray of {@code
831 * dst} starting at index {@code dstBegin} and ending at index:
832 *
833 * <blockquote><pre>
834 * dstbegin + (srcEnd-srcBegin) - 1
835 * </pre></blockquote>
836 *
837 * @deprecated This method does not properly convert characters into
838 * bytes. As of JDK 1.1, the preferred way to do this is via the
839 * {@link #getBytes()} method, which uses the platform's default charset.
840 *
841 * @param srcBegin
842 * Index of the first character in the string to copy
843 *
844 * @param srcEnd
845 * Index after the last character in the string to copy
846 *
847 * @param dst
848 * The destination array
849 *
850 * @param dstBegin
851 * The start offset in the destination array
852 *
853 * @throws IndexOutOfBoundsException
854 * If any of the following is true:
855 * <ul>
856 * <li> {@code srcBegin} is negative
857 * <li> {@code srcBegin} is greater than {@code srcEnd}
858 * <li> {@code srcEnd} is greater than the length of this String
859 * <li> {@code dstBegin} is negative
860 * <li> {@code dstBegin+(srcEnd-srcBegin)} is larger than {@code
861 * dst.length}
862 * </ul>
863 */
864 @Deprecated
865 public void getBytes(int srcBegin, int srcEnd, byte dst[], int dstBegin) {
866 if (srcBegin < 0) {
867 throw new StringIndexOutOfBoundsException(srcBegin);
868 }
869 if (srcEnd > value.length) {
870 throw new StringIndexOutOfBoundsException(srcEnd);
871 }
872 if (srcBegin > srcEnd) {
873 throw new StringIndexOutOfBoundsException(srcEnd - srcBegin);
874 }
875 Objects.requireNonNull(dst);
876
877 int j = dstBegin;
878 int n = srcEnd;
879 int i = srcBegin;
880 char[] val = value; /* avoid getfield opcode */
881
882 while (i < n) {
883 dst[j++] = (byte)val[i++];
884 }
885 }
886
887 /**
888 * Encodes this {@code String} into a sequence of bytes using the named
889 * charset, storing the result into a new byte array.
890 *
891 * <p> The behavior of this method when this string cannot be encoded in
892 * the given charset is unspecified. The {@link
893 * java.nio.charset.CharsetEncoder} class should be used when more control
894 * over the encoding process is required.
895 *
896 * @param charsetName
897 * The name of a supported {@linkplain java.nio.charset.Charset
898 * charset}
899 *
900 * @return The resultant byte array
901 *
902 * @throws UnsupportedEncodingException
903 * If the named charset is not supported
904 *
905 * @since JDK1.1
906 */
907 public byte[] getBytes(String charsetName)
908 throws UnsupportedEncodingException {
909 if (charsetName == null) throw new NullPointerException();
910 return StringCoding.encode(charsetName, value, 0, value.length);
911 }
912
913 /**
914 * Encodes this {@code String} into a sequence of bytes using the given
915 * {@linkplain java.nio.charset.Charset charset}, storing the result into a
916 * new byte array.
917 *
918 * <p> This method always replaces malformed-input and unmappable-character
919 * sequences with this charset's default replacement byte array. The
920 * {@link java.nio.charset.CharsetEncoder} class should be used when more
921 * control over the encoding process is required.
922 *
923 * @param charset
924 * The {@linkplain java.nio.charset.Charset} to be used to encode
925 * the {@code String}
926 *
927 * @return The resultant byte array
928 *
929 * @since 1.6
930 */
931 public byte[] getBytes(Charset charset) {
932 if (charset == null) throw new NullPointerException();
933 return StringCoding.encode(charset, value, 0, value.length);
934 }
935
936 /**
937 * Encodes this {@code String} into a sequence of bytes using the
938 * platform's default charset, storing the result into a new byte array.
939 *
940 * <p> The behavior of this method when this string cannot be encoded in
941 * the default charset is unspecified. The {@link
942 * java.nio.charset.CharsetEncoder} class should be used when more control
943 * over the encoding process is required.
944 *
945 * @return The resultant byte array
946 *
947 * @since JDK1.1
948 */
949 public byte[] getBytes() {
950 return StringCoding.encode(value, 0, value.length);
951 }
952
953 /**
954 * Compares this string to the specified object. The result is {@code
955 * true} if and only if the argument is not {@code null} and is a {@code
956 * String} object that represents the same sequence of characters as this
957 * object.
958 *
959 * @param anObject
960 * The object to compare this {@code String} against
961 *
962 * @return {@code true} if the given object represents a {@code String}
963 * equivalent to this string, {@code false} otherwise
964 *
965 * @see #compareTo(String)
966 * @see #equalsIgnoreCase(String)
967 */
968 public boolean equals(Object anObject) {
969 if (this == anObject) {
970 return true;
971 }
972 if (anObject instanceof String) {
973 String anotherString = (String) anObject;
974 int n = value.length;
975 if (n == anotherString.value.length) {
976 char v1[] = value;
977 char v2[] = anotherString.value;
978 int i = 0;
979 while (n-- != 0) {
980 if (v1[i] != v2[i])
981 return false;
982 i++;
983 }
984 return true;
985 }
986 }
987 return false;
988 }
989
990 /**
991 * Compares this string to the specified {@code StringBuffer}. The result
992 * is {@code true} if and only if this {@code String} represents the same
993 * sequence of characters as the specified {@code StringBuffer}. This method
994 * synchronizes on the {@code StringBuffer}.
995 *
996 * @param sb
997 * The {@code StringBuffer} to compare this {@code String} against
998 *
999 * @return {@code true} if this {@code String} represents the same
1000 * sequence of characters as the specified {@code StringBuffer},
1001 * {@code false} otherwise
1002 *
1003 * @since 1.4
1004 */
1005 public boolean contentEquals(StringBuffer sb) {
1006 return contentEquals((CharSequence) sb);
1007 }
1008
1009 private boolean nonSyncContentEquals(AbstractStringBuilder sb) {
1010 char v1[] = value;
1011 char v2[] = sb.getValue();
1012 int i = 0;
1013 int n = value.length;
1014 while (n-- != 0) {
1015 if (v1[i] != v2[i]) {
1016 return false;
1017 }
1018 i++;
1019 }
1020 return true;
1021 }
1022
1023 /**
1024 * Compares this string to the specified {@code CharSequence}. The
1025 * result is {@code true} if and only if this {@code String} represents the
1026 * same sequence of char values as the specified sequence. Note that if the
1027 * {@code CharSequence} is a {@code StringBuffer} then the method
1028 * synchronizes on it.
1029 *
1030 * @param cs
1031 * The sequence to compare this {@code String} against
1032 *
1033 * @return {@code true} if this {@code String} represents the same
1034 * sequence of char values as the specified sequence, {@code
1035 * false} otherwise
1036 *
1037 * @since 1.5
1038 */
1039 public boolean contentEquals(CharSequence cs) {
1040 if (value.length != cs.length())
1041 return false;
1042 // Argument is a StringBuffer, StringBuilder
1043 if (cs instanceof AbstractStringBuilder) {
1044 if (cs instanceof StringBuffer) {
1045 synchronized(cs) {
1046 return nonSyncContentEquals((AbstractStringBuilder)cs);
1047 }
1048 } else {
1049 return nonSyncContentEquals((AbstractStringBuilder)cs);
1050 }
1051 }
1052 // Argument is a String
1053 if (cs.equals(this))
1054 return true;
1055 // Argument is a generic CharSequence
1056 char v1[] = value;
1057 int i = 0;
1058 int n = value.length;
1059 while (n-- != 0) {
1060 if (v1[i] != cs.charAt(i))
1061 return false;
1062 i++;
1063 }
1064 return true;
1065 }
1066
1067 /**
1068 * Compares this {@code String} to another {@code String}, ignoring case
1069 * considerations. Two strings are considered equal ignoring case if they
1070 * are of the same length and corresponding characters in the two strings
1071 * are equal ignoring case.
1072 *
1073 * <p> Two characters {@code c1} and {@code c2} are considered the same
1074 * ignoring case if at least one of the following is true:
1075 * <ul>
1076 * <li> The two characters are the same (as compared by the
1077 * {@code ==} operator)
1078 * <li> Applying the method {@link
1079 * java.lang.Character#toUpperCase(char)} to each character
1080 * produces the same result
1081 * <li> Applying the method {@link
1082 * java.lang.Character#toLowerCase(char)} to each character
1083 * produces the same result
1084 * </ul>
1085 *
1086 * @param anotherString
1087 * The {@code String} to compare this {@code String} against
1088 *
1089 * @return {@code true} if the argument is not {@code null} and it
1090 * represents an equivalent {@code String} ignoring case; {@code
1091 * false} otherwise
1092 *
1093 * @see #equals(Object)
1094 */
1095 public boolean equalsIgnoreCase(String anotherString) {
1096 return (this == anotherString) ? true
1097 : (anotherString != null)
1098 && (anotherString.value.length == value.length)
1099 && regionMatches(true, 0, anotherString, 0, value.length);
1100 }
1101
1102 /**
1103 * Compares two strings lexicographically.
1104 * The comparison is based on the Unicode value of each character in
1105 * the strings. The character sequence represented by this
1106 * {@code String} object is compared lexicographically to the
1107 * character sequence represented by the argument string. The result is
1108 * a negative integer if this {@code String} object
1109 * lexicographically precedes the argument string. The result is a
1110 * positive integer if this {@code String} object lexicographically
1111 * follows the argument string. The result is zero if the strings
1112 * are equal; {@code compareTo} returns {@code 0} exactly when
1113 * the {@link #equals(Object)} method would return {@code true}.
1114 * <p>
1115 * This is the definition of lexicographic ordering. If two strings are
1116 * different, then either they have different characters at some index
1117 * that is a valid index for both strings, or their lengths are different,
1118 * or both. If they have different characters at one or more index
1119 * positions, let <i>k</i> be the smallest such index; then the string
1120 * whose character at position <i>k</i> has the smaller value, as
1121 * determined by using the < operator, lexicographically precedes the
1122 * other string. In this case, {@code compareTo} returns the
1123 * difference of the two character values at position {@code k} in
1124 * the two string -- that is, the value:
1125 * <blockquote><pre>
1126 * this.charAt(k)-anotherString.charAt(k)
1127 * </pre></blockquote>
1128 * If there is no index position at which they differ, then the shorter
1129 * string lexicographically precedes the longer string. In this case,
1130 * {@code compareTo} returns the difference of the lengths of the
1131 * strings -- that is, the value:
1132 * <blockquote><pre>
1133 * this.length()-anotherString.length()
1134 * </pre></blockquote>
1135 *
1136 * @param anotherString the {@code String} to be compared.
1137 * @return the value {@code 0} if the argument string is equal to
1138 * this string; a value less than {@code 0} if this string
1139 * is lexicographically less than the string argument; and a
1140 * value greater than {@code 0} if this string is
1141 * lexicographically greater than the string argument.
1142 */
1143 public int compareTo(String anotherString) {
1144 int len1 = value.length;
1145 int len2 = anotherString.value.length;
1146 int lim = Math.min(len1, len2);
1147 char v1[] = value;
1148 char v2[] = anotherString.value;
1149
1150 int k = 0;
1151 while (k < lim) {
1152 char c1 = v1[k];
1153 char c2 = v2[k];
1154 if (c1 != c2) {
1155 return c1 - c2;
1156 }
1157 k++;
1158 }
1159 return len1 - len2;
1160 }
1161
1162 /**
1163 * A Comparator that orders {@code String} objects as by
1164 * {@code compareToIgnoreCase}. This comparator is serializable.
1165 * <p>
1166 * Note that this Comparator does <em>not</em> take locale into account,
1167 * and will result in an unsatisfactory ordering for certain locales.
1168 * The java.text package provides <em>Collators</em> to allow
1169 * locale-sensitive ordering.
1170 *
1171 * @see java.text.Collator#compare(String, String)
1172 * @since 1.2
1173 */
1174 public static final Comparator<String> CASE_INSENSITIVE_ORDER
1175 = new CaseInsensitiveComparator();
1176 private static class CaseInsensitiveComparator
1177 implements Comparator<String>, java.io.Serializable {
1178 // use serialVersionUID from JDK 1.2.2 for interoperability
1179 private static final long serialVersionUID = 8575799808933029326L;
1180
1181 public int compare(String s1, String s2) {
1182 int n1 = s1.length();
1183 int n2 = s2.length();
1184 int min = Math.min(n1, n2);
1185 for (int i = 0; i < min; i++) {
1186 char c1 = s1.charAt(i);
1187 char c2 = s2.charAt(i);
1188 if (c1 != c2) {
1189 c1 = Character.toUpperCase(c1);
1190 c2 = Character.toUpperCase(c2);
1191 if (c1 != c2) {
1192 c1 = Character.toLowerCase(c1);
1193 c2 = Character.toLowerCase(c2);
1194 if (c1 != c2) {
1195 // No overflow because of numeric promotion
1196 return c1 - c2;
1197 }
1198 }
1199 }
1200 }
1201 return n1 - n2;
1202 }
1203
1204 /** Replaces the de-serialized object. */
1205 private Object readResolve() { return CASE_INSENSITIVE_ORDER; }
1206 }
1207
1208 /**
1209 * Compares two strings lexicographically, ignoring case
1210 * differences. This method returns an integer whose sign is that of
1211 * calling {@code compareTo} with normalized versions of the strings
1212 * where case differences have been eliminated by calling
1213 * {@code Character.toLowerCase(Character.toUpperCase(character))} on
1214 * each character.
1215 * <p>
1216 * Note that this method does <em>not</em> take locale into account,
1217 * and will result in an unsatisfactory ordering for certain locales.
1218 * The java.text package provides <em>collators</em> to allow
1219 * locale-sensitive ordering.
1220 *
1221 * @param str the {@code String} to be compared.
1222 * @return a negative integer, zero, or a positive integer as the
1223 * specified String is greater than, equal to, or less
1224 * than this String, ignoring case considerations.
1225 * @see java.text.Collator#compare(String, String)
1226 * @since 1.2
1227 */
1228 public int compareToIgnoreCase(String str) {
1229 return CASE_INSENSITIVE_ORDER.compare(this, str);
1230 }
1231
1232 /**
1233 * Tests if two string regions are equal.
1234 * <p>
1235 * A substring of this {@code String} object is compared to a substring
1236 * of the argument other. The result is true if these substrings
1237 * represent identical character sequences. The substring of this
1238 * {@code String} object to be compared begins at index {@code toffset}
1239 * and has length {@code len}. The substring of other to be compared
1240 * begins at index {@code ooffset} and has length {@code len}. The
1241 * result is {@code false} if and only if at least one of the following
1242 * is true:
1243 * <ul><li>{@code toffset} is negative.
1244 * <li>{@code ooffset} is negative.
1245 * <li>{@code toffset+len} is greater than the length of this
1246 * {@code String} object.
1247 * <li>{@code ooffset+len} is greater than the length of the other
1248 * argument.
1249 * <li>There is some nonnegative integer <i>k</i> less than {@code len}
1250 * such that:
1251 * <code>this.charAt(toffset+<i>k</i>) != other.charAt(ooffset+<i>k</i>)</code>
1252 * </ul>
1253 *
1254 * @param toffset the starting offset of the subregion in this string.
1255 * @param other the string argument.
1256 * @param ooffset the starting offset of the subregion in the string
1257 * argument.
1258 * @param len the number of characters to compare.
1259 * @return {@code true} if the specified subregion of this string
1260 * exactly matches the specified subregion of the string argument;
1261 * {@code false} otherwise.
1262 */
1263 public boolean regionMatches(int toffset, String other, int ooffset,
1264 int len) {
1265 char ta[] = value;
1266 int to = toffset;
1267 char pa[] = other.value;
1268 int po = ooffset;
1269 // Note: toffset, ooffset, or len might be near -1>>>1.
1270 if ((ooffset < 0) || (toffset < 0)
1271 || (toffset > (long)value.length - len)
1272 || (ooffset > (long)other.value.length - len)) {
1273 return false;
1274 }
1275 while (len-- > 0) {
1276 if (ta[to++] != pa[po++]) {
1277 return false;
1278 }
1279 }
1280 return true;
1281 }
1282
1283 /**
1284 * Tests if two string regions are equal.
1285 * <p>
1286 * A substring of this {@code String} object is compared to a substring
1287 * of the argument {@code other}. The result is {@code true} if these
1288 * substrings represent character sequences that are the same, ignoring
1289 * case if and only if {@code ignoreCase} is true. The substring of
1290 * this {@code String} object to be compared begins at index
1291 * {@code toffset} and has length {@code len}. The substring of
1292 * {@code other} to be compared begins at index {@code ooffset} and
1293 * has length {@code len}. The result is {@code false} if and only if
1294 * at least one of the following is true:
1295 * <ul><li>{@code toffset} is negative.
1296 * <li>{@code ooffset} is negative.
1297 * <li>{@code toffset+len} is greater than the length of this
1298 * {@code String} object.
1299 * <li>{@code ooffset+len} is greater than the length of the other
1300 * argument.
1301 * <li>{@code ignoreCase} is {@code false} and there is some nonnegative
1302 * integer <i>k</i> less than {@code len} such that:
1303 * <blockquote><pre>
1304 * this.charAt(toffset+k) != other.charAt(ooffset+k)
1305 * </pre></blockquote>
1306 * <li>{@code ignoreCase} is {@code true} and there is some nonnegative
1307 * integer <i>k</i> less than {@code len} such that:
1308 * <blockquote><pre>
1309 * Character.toLowerCase(this.charAt(toffset+k)) !=
1310 Character.toLowerCase(other.charAt(ooffset+k))
1311 * </pre></blockquote>
1312 * and:
1313 * <blockquote><pre>
1314 * Character.toUpperCase(this.charAt(toffset+k)) !=
1315 * Character.toUpperCase(other.charAt(ooffset+k))
1316 * </pre></blockquote>
1317 * </ul>
1318 *
1319 * @param ignoreCase if {@code true}, ignore case when comparing
1320 * characters.
1321 * @param toffset the starting offset of the subregion in this
1322 * string.
1323 * @param other the string argument.
1324 * @param ooffset the starting offset of the subregion in the string
1325 * argument.
1326 * @param len the number of characters to compare.
1327 * @return {@code true} if the specified subregion of this string
1328 * matches the specified subregion of the string argument;
1329 * {@code false} otherwise. Whether the matching is exact
1330 * or case insensitive depends on the {@code ignoreCase}
1331 * argument.
1332 */
1333 public boolean regionMatches(boolean ignoreCase, int toffset,
1334 String other, int ooffset, int len) {
1335 char ta[] = value;
1336 int to = toffset;
1337 char pa[] = other.value;
1338 int po = ooffset;
1339 // Note: toffset, ooffset, or len might be near -1>>>1.
1340 if ((ooffset < 0) || (toffset < 0)
1341 || (toffset > (long)value.length - len)
1342 || (ooffset > (long)other.value.length - len)) {
1343 return false;
1344 }
1345 while (len-- > 0) {
1346 char c1 = ta[to++];
1347 char c2 = pa[po++];
1348 if (c1 == c2) {
1349 continue;
1350 }
1351 if (ignoreCase) {
1352 // If characters don't match but case may be ignored,
1353 // try converting both characters to uppercase.
1354 // If the results match, then the comparison scan should
1355 // continue.
1356 char u1 = Character.toUpperCase(c1);
1357 char u2 = Character.toUpperCase(c2);
1358 if (u1 == u2) {
1359 continue;
1360 }
1361 // Unfortunately, conversion to uppercase does not work properly
1362 // for the Georgian alphabet, which has strange rules about case
1363 // conversion. So we need to make one last check before
1364 // exiting.
1365 if (Character.toLowerCase(u1) == Character.toLowerCase(u2)) {
1366 continue;
1367 }
1368 }
1369 return false;
1370 }
1371 return true;
1372 }
1373
1374 /**
1375 * Tests if the substring of this string beginning at the
1376 * specified index starts with the specified prefix.
1377 *
1378 * @param prefix the prefix.
1379 * @param toffset where to begin looking in this string.
1380 * @return {@code true} if the character sequence represented by the
1381 * argument is a prefix of the substring of this object starting
1382 * at index {@code toffset}; {@code false} otherwise.
1383 * The result is {@code false} if {@code toffset} is
1384 * negative or greater than the length of this
1385 * {@code String} object; otherwise the result is the same
1386 * as the result of the expression
1387 * <pre>
1388 * this.substring(toffset).startsWith(prefix)
1389 * </pre>
1390 */
1391 public boolean startsWith(String prefix, int toffset) {
1392 char ta[] = value;
1393 int to = toffset;
1394 char pa[] = prefix.value;
1395 int po = 0;
1396 int pc = prefix.value.length;
1397 // Note: toffset might be near -1>>>1.
1398 if ((toffset < 0) || (toffset > value.length - pc)) {
1399 return false;
1400 }
1401 while (--pc >= 0) {
1402 if (ta[to++] != pa[po++]) {
1403 return false;
1404 }
1405 }
1406 return true;
1407 }
1408
1409 /**
1410 * Tests if this string starts with the specified prefix.
1411 *
1412 * @param prefix the prefix.
1413 * @return {@code true} if the character sequence represented by the
1414 * argument is a prefix of the character sequence represented by
1415 * this string; {@code false} otherwise.
1416 * Note also that {@code true} will be returned if the
1417 * argument is an empty string or is equal to this
1418 * {@code String} object as determined by the
1419 * {@link #equals(Object)} method.
1420 * @since 1. 0
1421 */
1422 public boolean startsWith(String prefix) {
1423 return startsWith(prefix, 0);
1424 }
1425
1426 /**
1427 * Tests if this string ends with the specified suffix.
1428 *
1429 * @param suffix the suffix.
1430 * @return {@code true} if the character sequence represented by the
1431 * argument is a suffix of the character sequence represented by
1432 * this object; {@code false} otherwise. Note that the
1433 * result will be {@code true} if the argument is the
1434 * empty string or is equal to this {@code String} object
1435 * as determined by the {@link #equals(Object)} method.
1436 */
1437 public boolean endsWith(String suffix) {
1438 return startsWith(suffix, value.length - suffix.value.length);
1439 }
1440
1441 /**
1442 * Returns a hash code for this string. The hash code for a
1443 * {@code String} object is computed as
1444 * <blockquote><pre>
1445 * s[0]*31^(n-1) + s[1]*31^(n-2) + ... + s[n-1]
1446 * </pre></blockquote>
1447 * using {@code int} arithmetic, where {@code s[i]} is the
1448 * <i>i</i>th character of the string, {@code n} is the length of
1449 * the string, and {@code ^} indicates exponentiation.
1450 * (The hash value of the empty string is zero.)
1451 *
1452 * @return a hash code value for this object.
1453 */
1454 public int hashCode() {
1455 int h = hash;
1456 if (h == 0 && value.length > 0) {
1457 char val[] = value;
1458
1459 for (int i = 0; i < value.length; i++) {
1460 h = 31 * h + val[i];
1461 }
1462 hash = h;
1463 }
1464 return h;
1465 }
1466
1467 /**
1468 * Returns the index within this string of the first occurrence of
1469 * the specified character. If a character with value
1470 * {@code ch} occurs in the character sequence represented by
1471 * this {@code String} object, then the index (in Unicode
1472 * code units) of the first such occurrence is returned. For
1473 * values of {@code ch} in the range from 0 to 0xFFFF
1474 * (inclusive), this is the smallest value <i>k</i> such that:
1475 * <blockquote><pre>
1476 * this.charAt(<i>k</i>) == ch
1477 * </pre></blockquote>
1478 * is true. For other values of {@code ch}, it is the
1479 * smallest value <i>k</i> such that:
1480 * <blockquote><pre>
1481 * this.codePointAt(<i>k</i>) == ch
1482 * </pre></blockquote>
1483 * is true. In either case, if no such character occurs in this
1484 * string, then {@code -1} is returned.
1485 *
1486 * @param ch a character (Unicode code point).
1487 * @return the index of the first occurrence of the character in the
1488 * character sequence represented by this object, or
1489 * {@code -1} if the character does not occur.
1490 */
1491 public int indexOf(int ch) {
1492 return indexOf(ch, 0);
1493 }
1494
1495 /**
1496 * Returns the index within this string of the first occurrence of the
1497 * specified character, starting the search at the specified index.
1498 * <p>
1499 * If a character with value {@code ch} occurs in the
1500 * character sequence represented by this {@code String}
1501 * object at an index no smaller than {@code fromIndex}, then
1502 * the index of the first such occurrence is returned. For values
1503 * of {@code ch} in the range from 0 to 0xFFFF (inclusive),
1504 * this is the smallest value <i>k</i> such that:
1505 * <blockquote><pre>
1506 * (this.charAt(<i>k</i>) == ch) {@code &&} (<i>k</i> >= fromIndex)
1507 * </pre></blockquote>
1508 * is true. For other values of {@code ch}, it is the
1509 * smallest value <i>k</i> such that:
1510 * <blockquote><pre>
1511 * (this.codePointAt(<i>k</i>) == ch) {@code &&} (<i>k</i> >= fromIndex)
1512 * </pre></blockquote>
1513 * is true. In either case, if no such character occurs in this
1514 * string at or after position {@code fromIndex}, then
1515 * {@code -1} is returned.
1516 *
1517 * <p>
1518 * There is no restriction on the value of {@code fromIndex}. If it
1519 * is negative, it has the same effect as if it were zero: this entire
1520 * string may be searched. If it is greater than the length of this
1521 * string, it has the same effect as if it were equal to the length of
1522 * this string: {@code -1} is returned.
1523 *
1524 * <p>All indices are specified in {@code char} values
1525 * (Unicode code units).
1526 *
1527 * @param ch a character (Unicode code point).
1528 * @param fromIndex the index to start the search from.
1529 * @return the index of the first occurrence of the character in the
1530 * character sequence represented by this object that is greater
1531 * than or equal to {@code fromIndex}, or {@code -1}
1532 * if the character does not occur.
1533 */
1534 public int indexOf(int ch, int fromIndex) {
1535 final int max = value.length;
1536 if (fromIndex < 0) {
1537 fromIndex = 0;
1538 } else if (fromIndex >= max) {
1539 // Note: fromIndex might be near -1>>>1.
1540 return -1;
1541 }
1542
1543 if (ch < Character.MIN_SUPPLEMENTARY_CODE_POINT) {
1544 // handle most cases here (ch is a BMP code point or a
1545 // negative value (invalid code point))
1546 final char[] value = this.value;
1547 for (int i = fromIndex; i < max; i++) {
1548 if (value[i] == ch) {
1549 return i;
1550 }
1551 }
1552 return -1;
1553 } else {
1554 return indexOfSupplementary(ch, fromIndex);
1555 }
1556 }
1557
1558 /**
1559 * Handles (rare) calls of indexOf with a supplementary character.
1560 */
1561 private int indexOfSupplementary(int ch, int fromIndex) {
1562 if (Character.isValidCodePoint(ch)) {
1563 final char[] value = this.value;
1564 final char hi = Character.highSurrogate(ch);
1565 final char lo = Character.lowSurrogate(ch);
1566 final int max = value.length - 1;
1567 for (int i = fromIndex; i < max; i++) {
1568 if (value[i] == hi && value[i + 1] == lo) {
1569 return i;
1570 }
1571 }
1572 }
1573 return -1;
1574 }
1575
1576 /**
1577 * Returns the index within this string of the last occurrence of
1578 * the specified character. For values of {@code ch} in the
1579 * range from 0 to 0xFFFF (inclusive), the index (in Unicode code
1580 * units) returned is the largest value <i>k</i> such that:
1581 * <blockquote><pre>
1582 * this.charAt(<i>k</i>) == ch
1583 * </pre></blockquote>
1584 * is true. For other values of {@code ch}, it is the
1585 * largest value <i>k</i> such that:
1586 * <blockquote><pre>
1587 * this.codePointAt(<i>k</i>) == ch
1588 * </pre></blockquote>
1589 * is true. In either case, if no such character occurs in this
1590 * string, then {@code -1} is returned. The
1591 * {@code String} is searched backwards starting at the last
1592 * character.
1593 *
1594 * @param ch a character (Unicode code point).
1595 * @return the index of the last occurrence of the character in the
1596 * character sequence represented by this object, or
1597 * {@code -1} if the character does not occur.
1598 */
1599 public int lastIndexOf(int ch) {
1600 return lastIndexOf(ch, value.length - 1);
1601 }
1602
1603 /**
1604 * Returns the index within this string of the last occurrence of
1605 * the specified character, searching backward starting at the
1606 * specified index. For values of {@code ch} in the range
1607 * from 0 to 0xFFFF (inclusive), the index returned is the largest
1608 * value <i>k</i> such that:
1609 * <blockquote><pre>
1610 * (this.charAt(<i>k</i>) == ch) {@code &&} (<i>k</i> <= fromIndex)
1611 * </pre></blockquote>
1612 * is true. For other values of {@code ch}, it is the
1613 * largest value <i>k</i> such that:
1614 * <blockquote><pre>
1615 * (this.codePointAt(<i>k</i>) == ch) {@code &&} (<i>k</i> <= fromIndex)
1616 * </pre></blockquote>
1617 * is true. In either case, if no such character occurs in this
1618 * string at or before position {@code fromIndex}, then
1619 * {@code -1} is returned.
1620 *
1621 * <p>All indices are specified in {@code char} values
1622 * (Unicode code units).
1623 *
1624 * @param ch a character (Unicode code point).
1625 * @param fromIndex the index to start the search from. There is no
1626 * restriction on the value of {@code fromIndex}. If it is
1627 * greater than or equal to the length of this string, it has
1628 * the same effect as if it were equal to one less than the
1629 * length of this string: this entire string may be searched.
1630 * If it is negative, it has the same effect as if it were -1:
1631 * -1 is returned.
1632 * @return the index of the last occurrence of the character in the
1633 * character sequence represented by this object that is less
1634 * than or equal to {@code fromIndex}, or {@code -1}
1635 * if the character does not occur before that point.
1636 */
1637 public int lastIndexOf(int ch, int fromIndex) {
1638 if (ch < Character.MIN_SUPPLEMENTARY_CODE_POINT) {
1639 // handle most cases here (ch is a BMP code point or a
1640 // negative value (invalid code point))
1641 final char[] value = this.value;
1642 int i = Math.min(fromIndex, value.length - 1);
1643 for (; i >= 0; i--) {
1644 if (value[i] == ch) {
1645 return i;
1646 }
1647 }
1648 return -1;
1649 } else {
1650 return lastIndexOfSupplementary(ch, fromIndex);
1651 }
1652 }
1653
1654 /**
1655 * Handles (rare) calls of lastIndexOf with a supplementary character.
1656 */
1657 private int lastIndexOfSupplementary(int ch, int fromIndex) {
1658 if (Character.isValidCodePoint(ch)) {
1659 final char[] value = this.value;
1660 char hi = Character.highSurrogate(ch);
1661 char lo = Character.lowSurrogate(ch);
1662 int i = Math.min(fromIndex, value.length - 2);
1663 for (; i >= 0; i--) {
1664 if (value[i] == hi && value[i + 1] == lo) {
1665 return i;
1666 }
1667 }
1668 }
1669 return -1;
1670 }
1671
1672 /**
1673 * Returns the index within this string of the first occurrence of the
1674 * specified substring.
1675 *
1676 * <p>The returned index is the smallest value <i>k</i> for which:
1677 * <blockquote><pre>
1678 * this.startsWith(str, <i>k</i>)
1679 * </pre></blockquote>
1680 * If no such value of <i>k</i> exists, then {@code -1} is returned.
1681 *
1682 * @param str the substring to search for.
1683 * @return the index of the first occurrence of the specified substring,
1684 * or {@code -1} if there is no such occurrence.
1685 */
1686 public int indexOf(String str) {
1687 return indexOf(str, 0);
1688 }
1689
1690 /**
1691 * Returns the index within this string of the first occurrence of the
1692 * specified substring, starting at the specified index.
1693 *
1694 * <p>The returned index is the smallest value <i>k</i> for which:
1695 * <blockquote><pre>
1696 * <i>k</i> >= fromIndex {@code &&} this.startsWith(str, <i>k</i>)
1697 * </pre></blockquote>
1698 * If no such value of <i>k</i> exists, then {@code -1} is returned.
1699 *
1700 * @param str the substring to search for.
1701 * @param fromIndex the index from which to start the search.
1702 * @return the index of the first occurrence of the specified substring,
1703 * starting at the specified index,
1704 * or {@code -1} if there is no such occurrence.
1705 */
1706 public int indexOf(String str, int fromIndex) {
1707 return indexOf(value, 0, value.length,
1708 str.value, 0, str.value.length, fromIndex);
1709 }
1710
1711 /**
1712 * Code shared by String and AbstractStringBuilder to do searches. The
1713 * source is the character array being searched, and the target
1714 * is the string being searched for.
1715 *
1716 * @param source the characters being searched.
1717 * @param sourceOffset offset of the source string.
1718 * @param sourceCount count of the source string.
1719 * @param target the characters being searched for.
1720 * @param fromIndex the index to begin searching from.
1721 */
1722 static int indexOf(char[] source, int sourceOffset, int sourceCount,
1723 String target, int fromIndex) {
1724 return indexOf(source, sourceOffset, sourceCount,
1725 target.value, 0, target.value.length,
1726 fromIndex);
1727 }
1728
1729 /**
1730 * Code shared by String and StringBuffer to do searches. The
1731 * source is the character array being searched, and the target
1732 * is the string being searched for.
1733 *
1734 * @param source the characters being searched.
1735 * @param sourceOffset offset of the source string.
1736 * @param sourceCount count of the source string.
1737 * @param target the characters being searched for.
1738 * @param targetOffset offset of the target string.
1739 * @param targetCount count of the target string.
1740 * @param fromIndex the index to begin searching from.
1741 */
1742 static int indexOf(char[] source, int sourceOffset, int sourceCount,
1743 char[] target, int targetOffset, int targetCount,
1744 int fromIndex) {
1745 if (fromIndex >= sourceCount) {
1746 return (targetCount == 0 ? sourceCount : -1);
1747 }
1748 if (fromIndex < 0) {
1749 fromIndex = 0;
1750 }
1751 if (targetCount == 0) {
1752 return fromIndex;
1753 }
1754
1755 char first = target[targetOffset];
1756 int max = sourceOffset + (sourceCount - targetCount);
1757
1758 for (int i = sourceOffset + fromIndex; i <= max; i++) {
1759 /* Look for first character. */
1760 if (source[i] != first) {
1761 while (++i <= max && source[i] != first);
1762 }
1763
1764 /* Found first character, now look at the rest of v2 */
1765 if (i <= max) {
1766 int j = i + 1;
1767 int end = j + targetCount - 1;
1768 for (int k = targetOffset + 1; j < end && source[j]
1769 == target[k]; j++, k++);
1770
1771 if (j == end) {
1772 /* Found whole string. */
1773 return i - sourceOffset;
1774 }
1775 }
1776 }
1777 return -1;
1778 }
1779
1780 /**
1781 * Returns the index within this string of the last occurrence of the
1782 * specified substring. The last occurrence of the empty string ""
1783 * is considered to occur at the index value {@code this.length()}.
1784 *
1785 * <p>The returned index is the largest value <i>k</i> for which:
1786 * <blockquote><pre>
1787 * this.startsWith(str, <i>k</i>)
1788 * </pre></blockquote>
1789 * If no such value of <i>k</i> exists, then {@code -1} is returned.
1790 *
1791 * @param str the substring to search for.
1792 * @return the index of the last occurrence of the specified substring,
1793 * or {@code -1} if there is no such occurrence.
1794 */
1795 public int lastIndexOf(String str) {
1796 return lastIndexOf(str, value.length);
1797 }
1798
1799 /**
1800 * Returns the index within this string of the last occurrence of the
1801 * specified substring, searching backward starting at the specified index.
1802 *
1803 * <p>The returned index is the largest value <i>k</i> for which:
1804 * <blockquote><pre>
1805 * <i>k</i> {@code <=} fromIndex {@code &&} this.startsWith(str, <i>k</i>)
1806 * </pre></blockquote>
1807 * If no such value of <i>k</i> exists, then {@code -1} is returned.
1808 *
1809 * @param str the substring to search for.
1810 * @param fromIndex the index to start the search from.
1811 * @return the index of the last occurrence of the specified substring,
1812 * searching backward from the specified index,
1813 * or {@code -1} if there is no such occurrence.
1814 */
1815 public int lastIndexOf(String str, int fromIndex) {
1816 return lastIndexOf(value, 0, value.length,
1817 str.value, 0, str.value.length, fromIndex);
1818 }
1819
1820 /**
1821 * Code shared by String and AbstractStringBuilder to do searches. The
1822 * source is the character array being searched, and the target
1823 * is the string being searched for.
1824 *
1825 * @param source the characters being searched.
1826 * @param sourceOffset offset of the source string.
1827 * @param sourceCount count of the source string.
1828 * @param target the characters being searched for.
1829 * @param fromIndex the index to begin searching from.
1830 */
1831 static int lastIndexOf(char[] source, int sourceOffset, int sourceCount,
1832 String target, int fromIndex) {
1833 return lastIndexOf(source, sourceOffset, sourceCount,
1834 target.value, 0, target.value.length,
1835 fromIndex);
1836 }
1837
1838 /**
1839 * Code shared by String and StringBuffer to do searches. The
1840 * source is the character array being searched, and the target
1841 * is the string being searched for.
1842 *
1843 * @param source the characters being searched.
1844 * @param sourceOffset offset of the source string.
1845 * @param sourceCount count of the source string.
1846 * @param target the characters being searched for.
1847 * @param targetOffset offset of the target string.
1848 * @param targetCount count of the target string.
1849 * @param fromIndex the index to begin searching from.
1850 */
1851 static int lastIndexOf(char[] source, int sourceOffset, int sourceCount,
1852 char[] target, int targetOffset, int targetCount,
1853 int fromIndex) {
1854 /*
1855 * Check arguments; return immediately where possible. For
1856 * consistency, don't check for null str.
1857 */
1858 int rightIndex = sourceCount - targetCount;
1859 if (fromIndex < 0) {
1860 return -1;
1861 }
1862 if (fromIndex > rightIndex) {
1863 fromIndex = rightIndex;
1864 }
1865 /* Empty string always matches. */
1866 if (targetCount == 0) {
1867 return fromIndex;
1868 }
1869
1870 int strLastIndex = targetOffset + targetCount - 1;
1871 char strLastChar = target[strLastIndex];
1872 int min = sourceOffset + targetCount - 1;
1873 int i = min + fromIndex;
1874
1875 startSearchForLastChar:
1876 while (true) {
1877 while (i >= min && source[i] != strLastChar) {
1878 i--;
1879 }
1880 if (i < min) {
1881 return -1;
1882 }
1883 int j = i - 1;
1884 int start = j - (targetCount - 1);
1885 int k = strLastIndex - 1;
1886
1887 while (j > start) {
1888 if (source[j--] != target[k--]) {
1889 i--;
1890 continue startSearchForLastChar;
1891 }
1892 }
1893 return start - sourceOffset + 1;
1894 }
1895 }
1896
1897 /**
1898 * Returns a new string that is a substring of this string. The
1899 * substring begins with the character at the specified index and
1900 * extends to the end of this string. <p>
1901 * Examples:
1902 * <blockquote><pre>
1903 * "unhappy".substring(2) returns "happy"
1904 * "Harbison".substring(3) returns "bison"
1905 * "emptiness".substring(9) returns "" (an empty string)
1906 * </pre></blockquote>
1907 *
1908 * @param beginIndex the beginning index, inclusive.
1909 * @return the specified substring.
1910 * @exception IndexOutOfBoundsException if
1911 * {@code beginIndex} is negative or larger than the
1912 * length of this {@code String} object.
1913 */
1914 public String substring(int beginIndex) {
1915 if (beginIndex < 0) {
1916 throw new StringIndexOutOfBoundsException(beginIndex);
1917 }
1918 int subLen = value.length - beginIndex;
1919 if (subLen < 0) {
1920 throw new StringIndexOutOfBoundsException(subLen);
1921 }
1922 return (beginIndex == 0) ? this : new String(value, beginIndex, subLen);
1923 }
1924
1925 /**
1926 * Returns a new string that is a substring of this string. The
1927 * substring begins at the specified {@code beginIndex} and
1928 * extends to the character at index {@code endIndex - 1}.
1929 * Thus the length of the substring is {@code endIndex-beginIndex}.
1930 * <p>
1931 * Examples:
1932 * <blockquote><pre>
1933 * "hamburger".substring(4, 8) returns "urge"
1934 * "smiles".substring(1, 5) returns "mile"
1935 * </pre></blockquote>
1936 *
1937 * @param beginIndex the beginning index, inclusive.
1938 * @param endIndex the ending index, exclusive.
1939 * @return the specified substring.
1940 * @exception IndexOutOfBoundsException if the
1941 * {@code beginIndex} is negative, or
1942 * {@code endIndex} is larger than the length of
1943 * this {@code String} object, or
1944 * {@code beginIndex} is larger than
1945 * {@code endIndex}.
1946 */
1947 public String substring(int beginIndex, int endIndex) {
1948 if (beginIndex < 0) {
1949 throw new StringIndexOutOfBoundsException(beginIndex);
1950 }
1951 if (endIndex > value.length) {
1952 throw new StringIndexOutOfBoundsException(endIndex);
1953 }
1954 int subLen = endIndex - beginIndex;
1955 if (subLen < 0) {
1956 throw new StringIndexOutOfBoundsException(subLen);
1957 }
1958 return ((beginIndex == 0) && (endIndex == value.length)) ? this
1959 : new String(value, beginIndex, subLen);
1960 }
1961
1962 /**
1963 * Returns a new character sequence that is a subsequence of this sequence.
1964 *
1965 * <p> An invocation of this method of the form
1966 *
1967 * <blockquote><pre>
1968 * str.subSequence(begin, end)</pre></blockquote>
1969 *
1970 * behaves in exactly the same way as the invocation
1971 *
1972 * <blockquote><pre>
1973 * str.substring(begin, end)</pre></blockquote>
1974 *
1975 * This method is defined so that the {@code String} class can implement
1976 * the {@link CharSequence} interface. </p>
1977 *
1978 * @param beginIndex the begin index, inclusive.
1979 * @param endIndex the end index, exclusive.
1980 * @return the specified subsequence.
1981 *
1982 * @throws IndexOutOfBoundsException
1983 * if {@code beginIndex} or {@code endIndex} is negative,
1984 * if {@code endIndex} is greater than {@code length()},
1985 * or if {@code beginIndex} is greater than {@code endIndex}
1986 *
1987 * @since 1.4
1988 * @spec JSR-51
1989 */
1990 public CharSequence subSequence(int beginIndex, int endIndex) {
1991 return this.substring(beginIndex, endIndex);
1992 }
1993
1994 /**
1995 * Concatenates the specified string to the end of this string.
1996 * <p>
1997 * If the length of the argument string is {@code 0}, then this
1998 * {@code String} object is returned. Otherwise, a new
1999 * {@code String} object is created, representing a character
2000 * sequence that is the concatenation of the character sequence
2001 * represented by this {@code String} object and the character
2002 * sequence represented by the argument string.<p>
2003 * Examples:
2004 * <blockquote><pre>
2005 * "cares".concat("s") returns "caress"
2006 * "to".concat("get").concat("her") returns "together"
2007 * </pre></blockquote>
2008 *
2009 * @param str the {@code String} that is concatenated to the end
2010 * of this {@code String}.
2011 * @return a string that represents the concatenation of this object's
2012 * characters followed by the string argument's characters.
2013 */
2014 public String concat(String str) {
2015 int otherLen = str.length();
2016 if (otherLen == 0) {
2017 return this;
2018 }
2019 int len = value.length;
2020 char buf[] = Arrays.copyOf(value, len + otherLen);
2021 str.getChars(buf, len);
2022 return new String(buf, true);
2023 }
2024
2025 /**
2026 * Returns a new string resulting from replacing all occurrences of
2027 * {@code oldChar} in this string with {@code newChar}.
2028 * <p>
2029 * If the character {@code oldChar} does not occur in the
2030 * character sequence represented by this {@code String} object,
2031 * then a reference to this {@code String} object is returned.
2032 * Otherwise, a new {@code String} object is created that
2033 * represents a character sequence identical to the character sequence
2034 * represented by this {@code String} object, except that every
2035 * occurrence of {@code oldChar} is replaced by an occurrence
2036 * of {@code newChar}.
2037 * <p>
2038 * Examples:
2039 * <blockquote><pre>
2040 * "mesquite in your cellar".replace('e', 'o')
2041 * returns "mosquito in your collar"
2042 * "the war of baronets".replace('r', 'y')
2043 * returns "the way of bayonets"
2044 * "sparring with a purple porpoise".replace('p', 't')
2045 * returns "starring with a turtle tortoise"
2046 * "JonL".replace('q', 'x') returns "JonL" (no change)
2047 * </pre></blockquote>
2048 *
2049 * @param oldChar the old character.
2050 * @param newChar the new character.
2051 * @return a string derived from this string by replacing every
2052 * occurrence of {@code oldChar} with {@code newChar}.
2053 */
2054 public String replace(char oldChar, char newChar) {
2055 if (oldChar != newChar) {
2056 int len = value.length;
2057 int i = -1;
2058 char[] val = value; /* avoid getfield opcode */
2059
2060 while (++i < len) {
2061 if (val[i] == oldChar) {
2062 break;
2063 }
2064 }
2065 if (i < len) {
2066 char buf[] = new char[len];
2067 for (int j = 0; j < i; j++) {
2068 buf[j] = val[j];
2069 }
2070 while (i < len) {
2071 char c = val[i];
2072 buf[i] = (c == oldChar) ? newChar : c;
2073 i++;
2074 }
2075 return new String(buf, true);
2076 }
2077 }
2078 return this;
2079 }
2080
2081 /**
2082 * Tells whether or not this string matches the given <a
2083 * href="../util/regex/Pattern.html#sum">regular expression</a>.
2084 *
2085 * <p> An invocation of this method of the form
2086 * <i>str</i>{@code .matches(}<i>regex</i>{@code )} yields exactly the
2087 * same result as the expression
2088 *
2089 * <blockquote>
2090 * {@link java.util.regex.Pattern}.{@link java.util.regex.Pattern#matches(String,CharSequence)
2091 * matches(<i>regex</i>, <i>str</i>)}
2092 * </blockquote>
2093 *
2094 * @param regex
2095 * the regular expression to which this string is to be matched
2096 *
2097 * @return {@code true} if, and only if, this string matches the
2098 * given regular expression
2099 *
2100 * @throws PatternSyntaxException
2101 * if the regular expression's syntax is invalid
2102 *
2103 * @see java.util.regex.Pattern
2104 *
2105 * @since 1.4
2106 * @spec JSR-51
2107 */
2108 public boolean matches(String regex) {
2109 return Pattern.matches(regex, this);
2110 }
2111
2112 /**
2113 * Returns true if and only if this string contains the specified
2114 * sequence of char values.
2115 *
2116 * @param s the sequence to search for
2117 * @return true if this string contains {@code s}, false otherwise
2118 * @since 1.5
2119 */
2120 public boolean contains(CharSequence s) {
2121 return indexOf(s.toString()) > -1;
2122 }
2123
2124 /**
2125 * Replaces the first substring of this string that matches the given <a
2126 * href="../util/regex/Pattern.html#sum">regular expression</a> with the
2127 * given replacement.
2128 *
2129 * <p> An invocation of this method of the form
2130 * <i>str</i>{@code .replaceFirst(}<i>regex</i>{@code ,} <i>repl</i>{@code )}
2131 * yields exactly the same result as the expression
2132 *
2133 * <blockquote>
2134 * <code>
2135 * {@link java.util.regex.Pattern}.{@link
2136 * java.util.regex.Pattern#compile compile}(<i>regex</i>).{@link
2137 * java.util.regex.Pattern#matcher(java.lang.CharSequence) matcher}(<i>str</i>).{@link
2138 * java.util.regex.Matcher#replaceFirst replaceFirst}(<i>repl</i>)
2139 * </code>
2140 * </blockquote>
2141 *
2142 *<p>
2143 * Note that backslashes ({@code \}) and dollar signs ({@code $}) in the
2144 * replacement string may cause the results to be different than if it were
2145 * being treated as a literal replacement string; see
2146 * {@link java.util.regex.Matcher#replaceFirst}.
2147 * Use {@link java.util.regex.Matcher#quoteReplacement} to suppress the special
2148 * meaning of these characters, if desired.
2149 *
2150 * @param regex
2151 * the regular expression to which this string is to be matched
2152 * @param replacement
2153 * the string to be substituted for the first match
2154 *
2155 * @return The resulting {@code String}
2156 *
2157 * @throws PatternSyntaxException
2158 * if the regular expression's syntax is invalid
2159 *
2160 * @see java.util.regex.Pattern
2161 *
2162 * @since 1.4
2163 * @spec JSR-51
2164 */
2165 public String replaceFirst(String regex, String replacement) {
2166 return Pattern.compile(regex).matcher(this).replaceFirst(replacement);
2167 }
2168
2169 /**
2170 * Replaces each substring of this string that matches the given <a
2171 * href="../util/regex/Pattern.html#sum">regular expression</a> with the
2172 * given replacement.
2173 *
2174 * <p> An invocation of this method of the form
2175 * <i>str</i>{@code .replaceAll(}<i>regex</i>{@code ,} <i>repl</i>{@code )}
2176 * yields exactly the same result as the expression
2177 *
2178 * <blockquote>
2179 * <code>
2180 * {@link java.util.regex.Pattern}.{@link
2181 * java.util.regex.Pattern#compile compile}(<i>regex</i>).{@link
2182 * java.util.regex.Pattern#matcher(java.lang.CharSequence) matcher}(<i>str</i>).{@link
2183 * java.util.regex.Matcher#replaceAll replaceAll}(<i>repl</i>)
2184 * </code>
2185 * </blockquote>
2186 *
2187 *<p>
2188 * Note that backslashes ({@code \}) and dollar signs ({@code $}) in the
2189 * replacement string may cause the results to be different than if it were
2190 * being treated as a literal replacement string; see
2191 * {@link java.util.regex.Matcher#replaceAll Matcher.replaceAll}.
2192 * Use {@link java.util.regex.Matcher#quoteReplacement} to suppress the special
2193 * meaning of these characters, if desired.
2194 *
2195 * @param regex
2196 * the regular expression to which this string is to be matched
2197 * @param replacement
2198 * the string to be substituted for each match
2199 *
2200 * @return The resulting {@code String}
2201 *
2202 * @throws PatternSyntaxException
2203 * if the regular expression's syntax is invalid
2204 *
2205 * @see java.util.regex.Pattern
2206 *
2207 * @since 1.4
2208 * @spec JSR-51
2209 */
2210 public String replaceAll(String regex, String replacement) {
2211 return Pattern.compile(regex).matcher(this).replaceAll(replacement);
2212 }
2213
2214 /**
2215 * Replaces each substring of this string that matches the literal target
2216 * sequence with the specified literal replacement sequence. The
2217 * replacement proceeds from the beginning of the string to the end, for
2218 * example, replacing "aa" with "b" in the string "aaa" will result in
2219 * "ba" rather than "ab".
2220 *
2221 * @param target The sequence of char values to be replaced
2222 * @param replacement The replacement sequence of char values
2223 * @return The resulting string
2224 * @since 1.5
2225 */
2226 public String replace(CharSequence target, CharSequence replacement) {
2227 return Pattern.compile(target.toString(), Pattern.LITERAL).matcher(
2228 this).replaceAll(Matcher.quoteReplacement(replacement.toString()));
2229 }
2230
2231 /**
2232 * Splits this string around matches of the given
2233 * <a href="../util/regex/Pattern.html#sum">regular expression</a>.
2234 *
2235 * <p> The array returned by this method contains each substring of this
2236 * string that is terminated by another substring that matches the given
2237 * expression or is terminated by the end of the string. The substrings in
2238 * the array are in the order in which they occur in this string. If the
2239 * expression does not match any part of the input then the resulting array
2240 * has just one element, namely this string.
2241 *
2242 * <p> The {@code limit} parameter controls the number of times the
2243 * pattern is applied and therefore affects the length of the resulting
2244 * array. If the limit <i>n</i> is greater than zero then the pattern
2245 * will be applied at most <i>n</i> - 1 times, the array's
2246 * length will be no greater than <i>n</i>, and the array's last entry
2247 * will contain all input beyond the last matched delimiter. If <i>n</i>
2248 * is non-positive then the pattern will be applied as many times as
2249 * possible and the array can have any length. If <i>n</i> is zero then
2250 * the pattern will be applied as many times as possible, the array can
2251 * have any length, and trailing empty strings will be discarded.
2252 *
2253 * <p> The string {@code "boo:and:foo"}, for example, yields the
2254 * following results with these parameters:
2255 *
2256 * <blockquote><table cellpadding=1 cellspacing=0 summary="Split example showing regex, limit, and result">
2257 * <tr>
2258 * <th>Regex</th>
2259 * <th>Limit</th>
2260 * <th>Result</th>
2261 * </tr>
2262 * <tr><td align=center>:</td>
2263 * <td align=center>2</td>
2264 * <td>{@code { "boo", "and:foo" }}</td></tr>
2265 * <tr><td align=center>:</td>
2266 * <td align=center>5</td>
2267 * <td>{@code { "boo", "and", "foo" }}</td></tr>
2268 * <tr><td align=center>:</td>
2269 * <td align=center>-2</td>
2270 * <td>{@code { "boo", "and", "foo" }}</td></tr>
2271 * <tr><td align=center>o</td>
2272 * <td align=center>5</td>
2273 * <td>{@code { "b", "", ":and:f", "", "" }}</td></tr>
2274 * <tr><td align=center>o</td>
2275 * <td align=center>-2</td>
2276 * <td>{@code { "b", "", ":and:f", "", "" }}</td></tr>
2277 * <tr><td align=center>o</td>
2278 * <td align=center>0</td>
2279 * <td>{@code { "b", "", ":and:f" }}</td></tr>
2280 * </table></blockquote>
2281 *
2282 * <p> An invocation of this method of the form
2283 * <i>str.</i>{@code split(}<i>regex</i>{@code ,} <i>n</i>{@code )}
2284 * yields the same result as the expression
2285 *
2286 * <blockquote>
2287 * <code>
2288 * {@link java.util.regex.Pattern}.{@link
2289 * java.util.regex.Pattern#compile compile}(<i>regex</i>).{@link
2290 * java.util.regex.Pattern#split(java.lang.CharSequence,int) split}(<i>str</i>, <i>n</i>)
2291 * </code>
2292 * </blockquote>
2293 *
2294 *
2295 * @param regex
2296 * the delimiting regular expression
2297 *
2298 * @param limit
2299 * the result threshold, as described above
2300 *
2301 * @return the array of strings computed by splitting this string
2302 * around matches of the given regular expression
2303 *
2304 * @throws PatternSyntaxException
2305 * if the regular expression's syntax is invalid
2306 *
2307 * @see java.util.regex.Pattern
2308 *
2309 * @since 1.4
2310 * @spec JSR-51
2311 */
2312 public String[] split(String regex, int limit) {
2313 /* fastpath if the regex is a
2314 (1)one-char String and this character is not one of the
2315 RegEx's meta characters ".$|()[{^?*+\\", or
2316 (2)two-char String and the first char is the backslash and
2317 the second is not the ascii digit or ascii letter.
2318 */
2319 char ch = 0;
2320 if (((regex.value.length == 1 &&
2321 ".$|()[{^?*+\\".indexOf(ch = regex.charAt(0)) == -1) ||
2322 (regex.length() == 2 &&
2323 regex.charAt(0) == '\\' &&
2324 (((ch = regex.charAt(1))-'0')|('9'-ch)) < 0 &&
2325 ((ch-'a')|('z'-ch)) < 0 &&
2326 ((ch-'A')|('Z'-ch)) < 0)) &&
2327 (ch < Character.MIN_HIGH_SURROGATE ||
2328 ch > Character.MAX_LOW_SURROGATE))
2329 {
2330 int off = 0;
2331 int next = 0;
2332 boolean limited = limit > 0;
2333 ArrayList<String> list = new ArrayList<>();
2334 while ((next = indexOf(ch, off)) != -1) {
2335 if (!limited || list.size() < limit - 1) {
2336 list.add(substring(off, next));
2337 off = next + 1;
2338 } else { // last one
2339 //assert (list.size() == limit - 1);
2340 list.add(substring(off, value.length));
2341 off = value.length;
2342 break;
2343 }
2344 }
2345 // If no match was found, return this
2346 if (off == 0)
2347 return new String[]{this};
2348
2349 // Add remaining segment
2350 if (!limited || list.size() < limit)
2351 list.add(substring(off, value.length));
2352
2353 // Construct result
2354 int resultSize = list.size();
2355 if (limit == 0)
2356 while (resultSize > 0 && list.get(resultSize - 1).length() == 0)
2357 resultSize--;
2358 String[] result = new String[resultSize];
2359 return list.subList(0, resultSize).toArray(result);
2360 }
2361 return Pattern.compile(regex).split(this, limit);
2362 }
2363
2364 /**
2365 * Splits this string around matches of the given <a
2366 * href="../util/regex/Pattern.html#sum">regular expression</a>.
2367 *
2368 * <p> This method works as if by invoking the two-argument {@link
2369 * #split(String, int) split} method with the given expression and a limit
2370 * argument of zero. Trailing empty strings are therefore not included in
2371 * the resulting array.
2372 *
2373 * <p> The string {@code "boo:and:foo"}, for example, yields the following
2374 * results with these expressions:
2375 *
2376 * <blockquote><table cellpadding=1 cellspacing=0 summary="Split examples showing regex and result">
2377 * <tr>
2378 * <th>Regex</th>
2379 * <th>Result</th>
2380 * </tr>
2381 * <tr><td align=center>:</td>
2382 * <td>{@code { "boo", "and", "foo" }}</td></tr>
2383 * <tr><td align=center>o</td>
2384 * <td>{@code { "b", "", ":and:f" }}</td></tr>
2385 * </table></blockquote>
2386 *
2387 *
2388 * @param regex
2389 * the delimiting regular expression
2390 *
2391 * @return the array of strings computed by splitting this string
2392 * around matches of the given regular expression
2393 *
2394 * @throws PatternSyntaxException
2395 * if the regular expression's syntax is invalid
2396 *
2397 * @see java.util.regex.Pattern
2398 *
2399 * @since 1.4
2400 * @spec JSR-51
2401 */
2402 public String[] split(String regex) {
2403 return split(regex, 0);
2404 }
2405
2406 /**
2407 * Converts all of the characters in this {@code String} to lower
2408 * case using the rules of the given {@code Locale}. Case mapping is based
2409 * on the Unicode Standard version specified by the {@link java.lang.Character Character}
2410 * class. Since case mappings are not always 1:1 char mappings, the resulting
2411 * {@code String} may be a different length than the original {@code String}.
2412 * <p>
2413 * Examples of lowercase mappings are in the following table:
2414 * <table border="1" summary="Lowercase mapping examples showing language code of locale, upper case, lower case, and description">
2415 * <tr>
2416 * <th>Language Code of Locale</th>
2417 * <th>Upper Case</th>
2418 * <th>Lower Case</th>
2419 * <th>Description</th>
2420 * </tr>
2421 * <tr>
2422 * <td>tr (Turkish)</td>
2423 * <td>\u0130</td>
2424 * <td>\u0069</td>
2425 * <td>capital letter I with dot above -> small letter i</td>
2426 * </tr>
2427 * <tr>
2428 * <td>tr (Turkish)</td>
2429 * <td>\u0049</td>
2430 * <td>\u0131</td>
2431 * <td>capital letter I -> small letter dotless i </td>
2432 * </tr>
2433 * <tr>
2434 * <td>(all)</td>
2435 * <td>French Fries</td>
2436 * <td>french fries</td>
2437 * <td>lowercased all chars in String</td>
2438 * </tr>
2439 * <tr>
2440 * <td>(all)</td>
2441 * <td><img src="doc-files/capiota.gif" alt="capiota"><img src="doc-files/capchi.gif" alt="capchi">
2442 * <img src="doc-files/captheta.gif" alt="captheta"><img src="doc-files/capupsil.gif" alt="capupsil">
2443 * <img src="doc-files/capsigma.gif" alt="capsigma"></td>
2444 * <td><img src="doc-files/iota.gif" alt="iota"><img src="doc-files/chi.gif" alt="chi">
2445 * <img src="doc-files/theta.gif" alt="theta"><img src="doc-files/upsilon.gif" alt="upsilon">
2446 * <img src="doc-files/sigma1.gif" alt="sigma"></td>
2447 * <td>lowercased all chars in String</td>
2448 * </tr>
2449 * </table>
2450 *
2451 * @param locale use the case transformation rules for this locale
2452 * @return the {@code String}, converted to lowercase.
2453 * @see java.lang.String#toLowerCase()
2454 * @see java.lang.String#toUpperCase()
2455 * @see java.lang.String#toUpperCase(Locale)
2456 * @since 1.1
2457 */
2458 public String toLowerCase(Locale locale) {
2459 if (locale == null) {
2460 throw new NullPointerException();
2461 }
2462
2463 int firstUpper;
2464 final int len = value.length;
2465
2466 /* Now check if there are any characters that need to be changed. */
2467 scan: {
2468 for (firstUpper = 0 ; firstUpper < len; ) {
2469 char c = value[firstUpper];
2470 if ((c >= Character.MIN_HIGH_SURROGATE)
2471 && (c <= Character.MAX_HIGH_SURROGATE)) {
2472 int supplChar = codePointAt(firstUpper);
2473 if (supplChar != Character.toLowerCase(supplChar)) {
2474 break scan;
2475 }
2476 firstUpper += Character.charCount(supplChar);
2477 } else {
2478 if (c != Character.toLowerCase(c)) {
2479 break scan;
2480 }
2481 firstUpper++;
2482 }
2483 }
2484 return this;
2485 }
2486
2487 char[] result = new char[len];
2488 int resultOffset = 0; /* result may grow, so i+resultOffset
2489 * is the write location in result */
2490
2491 /* Just copy the first few lowerCase characters. */
2492 System.arraycopy(value, 0, result, 0, firstUpper);
2493
2494 String lang = locale.getLanguage();
2495 boolean localeDependent =
2496 (lang == "tr" || lang == "az" || lang == "lt");
2497 char[] lowerCharArray;
2498 int lowerChar;
2499 int srcChar;
2500 int srcCount;
2501 for (int i = firstUpper; i < len; i += srcCount) {
2502 srcChar = (int)value[i];
2503 if ((char)srcChar >= Character.MIN_HIGH_SURROGATE
2504 && (char)srcChar <= Character.MAX_HIGH_SURROGATE) {
2505 srcChar = codePointAt(i);
2506 srcCount = Character.charCount(srcChar);
2507 } else {
2508 srcCount = 1;
2509 }
2510 if (localeDependent || srcChar == '\u03A3') { // GREEK CAPITAL LETTER SIGMA
2511 lowerChar = ConditionalSpecialCasing.toLowerCaseEx(this, i, locale);
2512 } else if (srcChar == '\u0130') { // LATIN CAPITAL LETTER I DOT
2513 lowerChar = Character.ERROR;
2514 } else {
2515 lowerChar = Character.toLowerCase(srcChar);
2516 }
2517 if ((lowerChar == Character.ERROR)
2518 || (lowerChar >= Character.MIN_SUPPLEMENTARY_CODE_POINT)) {
2519 if (lowerChar == Character.ERROR) {
2520 if (!localeDependent && srcChar == '\u0130') {
2521 lowerCharArray =
2522 ConditionalSpecialCasing.toLowerCaseCharArray(this, i, Locale.ENGLISH);
2523 } else {
2524 lowerCharArray =
2525 ConditionalSpecialCasing.toLowerCaseCharArray(this, i, locale);
2526 }
2527 } else if (srcCount == 2) {
2528 resultOffset += Character.toChars(lowerChar, result, i + resultOffset) - srcCount;
2529 continue;
2530 } else {
2531 lowerCharArray = Character.toChars(lowerChar);
2532 }
2533
2534 /* Grow result if needed */
2535 int mapLen = lowerCharArray.length;
2536 if (mapLen > srcCount) {
2537 char[] result2 = new char[result.length + mapLen - srcCount];
2538 System.arraycopy(result, 0, result2, 0, i + resultOffset);
2539 result = result2;
2540 }
2541 for (int x = 0; x < mapLen; ++x) {
2542 result[i + resultOffset + x] = lowerCharArray[x];
2543 }
2544 resultOffset += (mapLen - srcCount);
2545 } else {
2546 result[i + resultOffset] = (char)lowerChar;
2547 }
2548 }
2549 return new String(result, 0, len + resultOffset);
2550 }
2551
2552 /**
2553 * Converts all of the characters in this {@code String} to lower
2554 * case using the rules of the default locale. This is equivalent to calling
2555 * {@code toLowerCase(Locale.getDefault())}.
2556 * <p>
2557 * <b>Note:</b> This method is locale sensitive, and may produce unexpected
2558 * results if used for strings that are intended to be interpreted locale
2559 * independently.
2560 * Examples are programming language identifiers, protocol keys, and HTML
2561 * tags.
2562 * For instance, {@code "TITLE".toLowerCase()} in a Turkish locale
2563 * returns {@code "t\u005Cu0131tle"}, where '\u005Cu0131' is the
2564 * LATIN SMALL LETTER DOTLESS I character.
2565 * To obtain correct results for locale insensitive strings, use
2566 * {@code toLowerCase(Locale.ENGLISH)}.
2567 * <p>
2568 * @return the {@code String}, converted to lowercase.
2569 * @see java.lang.String#toLowerCase(Locale)
2570 */
2571 public String toLowerCase() {
2572 return toLowerCase(Locale.getDefault());
2573 }
2574
2575 /**
2576 * Converts all of the characters in this {@code String} to upper
2577 * case using the rules of the given {@code Locale}. Case mapping is based
2578 * on the Unicode Standard version specified by the {@link java.lang.Character Character}
2579 * class. Since case mappings are not always 1:1 char mappings, the resulting
2580 * {@code String} may be a different length than the original {@code String}.
2581 * <p>
2582 * Examples of locale-sensitive and 1:M case mappings are in the following table.
2583 * <p>
2584 * <table border="1" summary="Examples of locale-sensitive and 1:M case mappings. Shows Language code of locale, lower case, upper case, and description.">
2585 * <tr>
2586 * <th>Language Code of Locale</th>
2587 * <th>Lower Case</th>
2588 * <th>Upper Case</th>
2589 * <th>Description</th>
2590 * </tr>
2591 * <tr>
2592 * <td>tr (Turkish)</td>
2593 * <td>\u0069</td>
2594 * <td>\u0130</td>
2595 * <td>small letter i -> capital letter I with dot above</td>
2596 * </tr>
2597 * <tr>
2598 * <td>tr (Turkish)</td>
2599 * <td>\u0131</td>
2600 * <td>\u0049</td>
2601 * <td>small letter dotless i -> capital letter I</td>
2602 * </tr>
2603 * <tr>
2604 * <td>(all)</td>
2605 * <td>\u00df</td>
2606 * <td>\u0053 \u0053</td>
2607 * <td>small letter sharp s -> two letters: SS</td>
2608 * </tr>
2609 * <tr>
2610 * <td>(all)</td>
2611 * <td>Fahrvergnügen</td>
2612 * <td>FAHRVERGNÜGEN</td>
2613 * <td></td>
2614 * </tr>
2615 * </table>
2616 * @param locale use the case transformation rules for this locale
2617 * @return the {@code String}, converted to uppercase.
2618 * @see java.lang.String#toUpperCase()
2619 * @see java.lang.String#toLowerCase()
2620 * @see java.lang.String#toLowerCase(Locale)
2621 * @since 1.1
2622 */
2623 public String toUpperCase(Locale locale) {
2624 if (locale == null) {
2625 throw new NullPointerException();
2626 }
2627
2628 int firstLower;
2629 final int len = value.length;
2630
2631 /* Now check if there are any characters that need to be changed. */
2632 scan: {
2633 for (firstLower = 0 ; firstLower < len; ) {
2634 int c = (int)value[firstLower];
2635 int srcCount;
2636 if ((c >= Character.MIN_HIGH_SURROGATE)
2637 && (c <= Character.MAX_HIGH_SURROGATE)) {
2638 c = codePointAt(firstLower);
2639 srcCount = Character.charCount(c);
2640 } else {
2641 srcCount = 1;
2642 }
2643 int upperCaseChar = Character.toUpperCaseEx(c);
2644 if ((upperCaseChar == Character.ERROR)
2645 || (c != upperCaseChar)) {
2646 break scan;
2647 }
2648 firstLower += srcCount;
2649 }
2650 return this;
2651 }
2652
2653 char[] result = new char[len]; /* may grow */
2654 int resultOffset = 0; /* result may grow, so i+resultOffset
2655 * is the write location in result */
2656
2657 /* Just copy the first few upperCase characters. */
2658 System.arraycopy(value, 0, result, 0, firstLower);
2659
2660 String lang = locale.getLanguage();
2661 boolean localeDependent =
2662 (lang == "tr" || lang == "az" || lang == "lt");
2663 char[] upperCharArray;
2664 int upperChar;
2665 int srcChar;
2666 int srcCount;
2667 for (int i = firstLower; i < len; i += srcCount) {
2668 srcChar = (int)value[i];
2669 if ((char)srcChar >= Character.MIN_HIGH_SURROGATE &&
2670 (char)srcChar <= Character.MAX_HIGH_SURROGATE) {
2671 srcChar = codePointAt(i);
2672 srcCount = Character.charCount(srcChar);
2673 } else {
2674 srcCount = 1;
2675 }
2676 if (localeDependent) {
2677 upperChar = ConditionalSpecialCasing.toUpperCaseEx(this, i, locale);
2678 } else {
2679 upperChar = Character.toUpperCaseEx(srcChar);
2680 }
2681 if ((upperChar == Character.ERROR)
2682 || (upperChar >= Character.MIN_SUPPLEMENTARY_CODE_POINT)) {
2683 if (upperChar == Character.ERROR) {
2684 if (localeDependent) {
2685 upperCharArray =
2686 ConditionalSpecialCasing.toUpperCaseCharArray(this, i, locale);
2687 } else {
2688 upperCharArray = Character.toUpperCaseCharArray(srcChar);
2689 }
2690 } else if (srcCount == 2) {
2691 resultOffset += Character.toChars(upperChar, result, i + resultOffset) - srcCount;
2692 continue;
2693 } else {
2694 upperCharArray = Character.toChars(upperChar);
2695 }
2696
2697 /* Grow result if needed */
2698 int mapLen = upperCharArray.length;
2699 if (mapLen > srcCount) {
2700 char[] result2 = new char[result.length + mapLen - srcCount];
2701 System.arraycopy(result, 0, result2, 0, i + resultOffset);
2702 result = result2;
2703 }
2704 for (int x = 0; x < mapLen; ++x) {
2705 result[i + resultOffset + x] = upperCharArray[x];
2706 }
2707 resultOffset += (mapLen - srcCount);
2708 } else {
2709 result[i + resultOffset] = (char)upperChar;
2710 }
2711 }
2712 return new String(result, 0, len + resultOffset);
2713 }
2714
2715 /**
2716 * Converts all of the characters in this {@code String} to upper
2717 * case using the rules of the default locale. This method is equivalent to
2718 * {@code toUpperCase(Locale.getDefault())}.
2719 * <p>
2720 * <b>Note:</b> This method is locale sensitive, and may produce unexpected
2721 * results if used for strings that are intended to be interpreted locale
2722 * independently.
2723 * Examples are programming language identifiers, protocol keys, and HTML
2724 * tags.
2725 * For instance, {@code "title".toUpperCase()} in a Turkish locale
2726 * returns {@code "T\u005Cu0130TLE"}, where '\u005Cu0130' is the
2727 * LATIN CAPITAL LETTER I WITH DOT ABOVE character.
2728 * To obtain correct results for locale insensitive strings, use
2729 * {@code toUpperCase(Locale.ENGLISH)}.
2730 * <p>
2731 * @return the {@code String}, converted to uppercase.
2732 * @see java.lang.String#toUpperCase(Locale)
2733 */
2734 public String toUpperCase() {
2735 return toUpperCase(Locale.getDefault());
2736 }
2737
2738 /**
2739 * Returns a copy of the string, with leading and trailing whitespace
2740 * omitted.
2741 * <p>
2742 * If this {@code String} object represents an empty character
2743 * sequence, or the first and last characters of character sequence
2744 * represented by this {@code String} object both have codes
2745 * greater than {@code '\u005Cu0020'} (the space character), then a
2746 * reference to this {@code String} object is returned.
2747 * <p>
2748 * Otherwise, if there is no character with a code greater than
2749 * {@code '\u005Cu0020'} in the string, then a new
2750 * {@code String} object representing an empty string is created
2751 * and returned.
2752 * <p>
2753 * Otherwise, let <i>k</i> be the index of the first character in the
2754 * string whose code is greater than {@code '\u005Cu0020'}, and let
2755 * <i>m</i> be the index of the last character in the string whose code
2756 * is greater than {@code '\u005Cu0020'}. A new {@code String}
2757 * object is created, representing the substring of this string that
2758 * begins with the character at index <i>k</i> and ends with the
2759 * character at index <i>m</i>-that is, the result of
2760 * <code>this.substring(<i>k</i>, <i>m</i>+1)</code>.
2761 * <p>
2762 * This method may be used to trim whitespace (as defined above) from
2763 * the beginning and end of a string.
2764 *
2765 * @return A copy of this string with leading and trailing white
2766 * space removed, or this string if it has no leading or
2767 * trailing white space.
2768 */
2769 public String trim() {
2770 int len = value.length;
2771 int st = 0;
2772 char[] val = value; /* avoid getfield opcode */
2773
2774 while ((st < len) && (val[st] <= ' ')) {
2775 st++;
2776 }
2777 while ((st < len) && (val[len - 1] <= ' ')) {
2778 len--;
2779 }
2780 return ((st > 0) || (len < value.length)) ? substring(st, len) : this;
2781 }
2782
2783 /**
2784 * This object (which is already a string!) is itself returned.
2785 *
2786 * @return the string itself.
2787 */
2788 public String toString() {
2789 return this;
2790 }
2791
2792 /**
2793 * Converts this string to a new character array.
2794 *
2795 * @return a newly allocated character array whose length is the length
2796 * of this string and whose contents are initialized to contain
2797 * the character sequence represented by this string.
2798 */
2799 public char[] toCharArray() {
2800 // Cannot use Arrays.copyOf because of class initialization order issues
2801 char result[] = new char[value.length];
2802 System.arraycopy(value, 0, result, 0, value.length);
2803 return result;
2804 }
2805
2806 /**
2807 * Returns a formatted string using the specified format string and
2808 * arguments.
2809 *
2810 * <p> The locale always used is the one returned by {@link
2811 * java.util.Locale#getDefault() Locale.getDefault()}.
2812 *
2813 * @param format
2814 * A <a href="../util/Formatter.html#syntax">format string</a>
2815 *
2816 * @param args
2817 * Arguments referenced by the format specifiers in the format
2818 * string. If there are more arguments than format specifiers, the
2819 * extra arguments are ignored. The number of arguments is
2820 * variable and may be zero. The maximum number of arguments is
2821 * limited by the maximum dimension of a Java array as defined by
2822 * <cite>The Java™ Virtual Machine Specification</cite>.
2823 * The behaviour on a
2824 * {@code null} argument depends on the <a
2825 * href="../util/Formatter.html#syntax">conversion</a>.
2826 *
2827 * @throws java.util.IllegalFormatException
2828 * If a format string contains an illegal syntax, a format
2829 * specifier that is incompatible with the given arguments,
2830 * insufficient arguments given the format string, or other
2831 * illegal conditions. For specification of all possible
2832 * formatting errors, see the <a
2833 * href="../util/Formatter.html#detail">Details</a> section of the
2834 * formatter class specification.
2835 *
2836 * @return A formatted string
2837 *
2838 * @see java.util.Formatter
2839 * @since 1.5
2840 */
2841 public static String format(String format, Object... args) {
2842 return new Formatter().format(format, args).toString();
2843 }
2844
2845 /**
2846 * Returns a formatted string using the specified locale, format string,
2847 * and arguments.
2848 *
2849 * @param l
2850 * The {@linkplain java.util.Locale locale} to apply during
2851 * formatting. If {@code l} is {@code null} then no localization
2852 * is applied.
2853 *
2854 * @param format
2855 * A <a href="../util/Formatter.html#syntax">format string</a>
2856 *
2857 * @param args
2858 * Arguments referenced by the format specifiers in the format
2859 * string. If there are more arguments than format specifiers, the
2860 * extra arguments are ignored. The number of arguments is
2861 * variable and may be zero. The maximum number of arguments is
2862 * limited by the maximum dimension of a Java array as defined by
2863 * <cite>The Java™ Virtual Machine Specification</cite>.
2864 * The behaviour on a
2865 * {@code null} argument depends on the
2866 * <a href="../util/Formatter.html#syntax">conversion</a>.
2867 *
2868 * @throws java.util.IllegalFormatException
2869 * If a format string contains an illegal syntax, a format
2870 * specifier that is incompatible with the given arguments,
2871 * insufficient arguments given the format string, or other
2872 * illegal conditions. For specification of all possible
2873 * formatting errors, see the <a
2874 * href="../util/Formatter.html#detail">Details</a> section of the
2875 * formatter class specification
2876 *
2877 * @return A formatted string
2878 *
2879 * @see java.util.Formatter
2880 * @since 1.5
2881 */
2882 public static String format(Locale l, String format, Object... args) {
2883 return new Formatter(l).format(format, args).toString();
2884 }
2885
2886 /**
2887 * Returns the string representation of the {@code Object} argument.
2888 *
2889 * @param obj an {@code Object}.
2890 * @return if the argument is {@code null}, then a string equal to
2891 * {@code "null"}; otherwise, the value of
2892 * {@code obj.toString()} is returned.
2893 * @see java.lang.Object#toString()
2894 */
2895 public static String valueOf(Object obj) {
2896 return (obj == null) ? "null" : obj.toString();
2897 }
2898
2899 /**
2900 * Returns the string representation of the {@code char} array
2901 * argument. The contents of the character array are copied; subsequent
2902 * modification of the character array does not affect the newly
2903 * created string.
2904 *
2905 * @param data a {@code char} array.
2906 * @return a newly allocated string representing the same sequence of
2907 * characters contained in the character array argument.
2908 */
2909 public static String valueOf(char data[]) {
2910 return new String(data);
2911 }
2912
2913 /**
2914 * Returns the string representation of a specific subarray of the
2915 * {@code char} array argument.
2916 * <p>
2917 * The {@code offset} argument is the index of the first
2918 * character of the subarray. The {@code count} argument
2919 * specifies the length of the subarray. The contents of the subarray
2920 * are copied; subsequent modification of the character array does not
2921 * affect the newly created string.
2922 *
2923 * @param data the character array.
2924 * @param offset the initial offset into the value of the
2925 * {@code String}.
2926 * @param count the length of the value of the {@code String}.
2927 * @return a string representing the sequence of characters contained
2928 * in the subarray of the character array argument.
2929 * @exception IndexOutOfBoundsException if {@code offset} is
2930 * negative, or {@code count} is negative, or
2931 * {@code offset+count} is larger than
2932 * {@code data.length}.
2933 */
2934 public static String valueOf(char data[], int offset, int count) {
2935 return new String(data, offset, count);
2936 }
2937
2938 /**
2939 * Returns a String that represents the character sequence in the
2940 * array specified.
2941 *
2942 * @param data the character array.
2943 * @param offset initial offset of the subarray.
2944 * @param count length of the subarray.
2945 * @return a {@code String} that contains the characters of the
2946 * specified subarray of the character array.
2947 */
2948 public static String copyValueOf(char data[], int offset, int count) {
2949 // All public String constructors now copy the data.
2950 return new String(data, offset, count);
2951 }
2952
2953 /**
2954 * Returns a String that represents the character sequence in the
2955 * array specified.
2956 *
2957 * @param data the character array.
2958 * @return a {@code String} that contains the characters of the
2959 * character array.
2960 */
2961 public static String copyValueOf(char data[]) {
2962 return new String(data);
2963 }
2964
2965 /**
2966 * Returns the string representation of the {@code boolean} argument.
2967 *
2968 * @param b a {@code boolean}.
2969 * @return if the argument is {@code true}, a string equal to
2970 * {@code "true"} is returned; otherwise, a string equal to
2971 * {@code "false"} is returned.
2972 */
2973 public static String valueOf(boolean b) {
2974 return b ? "true" : "false";
2975 }
2976
2977 /**
2978 * Returns the string representation of the {@code char}
2979 * argument.
2980 *
2981 * @param c a {@code char}.
2982 * @return a string of length {@code 1} containing
2983 * as its single character the argument {@code c}.
2984 */
2985 public static String valueOf(char c) {
2986 char data[] = {c};
2987 return new String(data, true);
2988 }
2989
2990 /**
2991 * Returns the string representation of the {@code int} argument.
2992 * <p>
2993 * The representation is exactly the one returned by the
2994 * {@code Integer.toString} method of one argument.
2995 *
2996 * @param i an {@code int}.
2997 * @return a string representation of the {@code int} argument.
2998 * @see java.lang.Integer#toString(int, int)
2999 */
3000 public static String valueOf(int i) {
3001 return Integer.toString(i);
3002 }
3003
3004 /**
3005 * Returns the string representation of the {@code long} argument.
3006 * <p>
3007 * The representation is exactly the one returned by the
3008 * {@code Long.toString} method of one argument.
3009 *
3010 * @param l a {@code long}.
3011 * @return a string representation of the {@code long} argument.
3012 * @see java.lang.Long#toString(long)
3013 */
3014 public static String valueOf(long l) {
3015 return Long.toString(l);
3016 }
3017
3018 /**
3019 * Returns the string representation of the {@code float} argument.
3020 * <p>
3021 * The representation is exactly the one returned by the
3022 * {@code Float.toString} method of one argument.
3023 *
3024 * @param f a {@code float}.
3025 * @return a string representation of the {@code float} argument.
3026 * @see java.lang.Float#toString(float)
3027 */
3028 public static String valueOf(float f) {
3029 return Float.toString(f);
3030 }
3031
3032 /**
3033 * Returns the string representation of the {@code double} argument.
3034 * <p>
3035 * The representation is exactly the one returned by the
3036 * {@code Double.toString} method of one argument.
3037 *
3038 * @param d a {@code double}.
3039 * @return a string representation of the {@code double} argument.
3040 * @see java.lang.Double#toString(double)
3041 */
3042 public static String valueOf(double d) {
3043 return Double.toString(d);
3044 }
3045
3046 /**
3047 * Returns a canonical representation for the string object.
3048 * <p>
3049 * A pool of strings, initially empty, is maintained privately by the
3050 * class {@code String}.
3051 * <p>
3052 * When the intern method is invoked, if the pool already contains a
3053 * string equal to this {@code String} object as determined by
3054 * the {@link #equals(Object)} method, then the string from the pool is
3055 * returned. Otherwise, this {@code String} object is added to the
3056 * pool and a reference to this {@code String} object is returned.
3057 * <p>
3058 * It follows that for any two strings {@code s} and {@code t},
3059 * {@code s.intern() == t.intern()} is {@code true}
3060 * if and only if {@code s.equals(t)} is {@code true}.
3061 * <p>
3062 * All literal strings and string-valued constant expressions are
3063 * interned. String literals are defined in section 3.10.5 of the
3064 * <cite>The Java™ Language Specification</cite>.
3065 *
3066 * @return a string that has the same contents as this string, but is
3067 * guaranteed to be from a pool of unique strings.
3068 */
3069 public native String intern();
3070
3071 /**
3072 * Seed value used for each alternative hash calculated.
3073 */
3074 private static final int HASHING_SEED;
3075
3076 static {
3077 long nanos = System.nanoTime();
3078 long now = System.currentTimeMillis();
3079 int SEED_MATERIAL[] = {
3080 System.identityHashCode(String.class),
3081 System.identityHashCode(System.class),
3082 (int) (nanos >>> 32),
3083 (int) nanos,
3084 (int) (now >>> 32),
3085 (int) now,
3086 (int) (System.nanoTime() >>> 2)
3087 };
3088
3089 // Use murmur3 to scramble the seeding material.
3090 // Inline implementation to avoid loading classes
3091 int h1 = 0;
3092
3093 // body
3094 for(int k1 : SEED_MATERIAL) {
3095 k1 *= 0xcc9e2d51;
3096 k1 = (k1 << 15) | (k1 >>> 17);
3097 k1 *= 0x1b873593;
3098
3099 h1 ^= k1;
3100 h1 = (h1 << 13) | (h1 >>> 19);
3101 h1 = h1 * 5 + 0xe6546b64;
3102 }
3103
3104 // tail (always empty, as body is always 32-bit chunks)
3105
3106 // finalization
3107
3108 h1 ^= SEED_MATERIAL.length * 4;
3109
3110 // finalization mix force all bits of a hash block to avalanche
3111 h1 ^= h1 >>> 16;
3112 h1 *= 0x85ebca6b;
3113 h1 ^= h1 >>> 13;
3114 h1 *= 0xc2b2ae35;
3115 h1 ^= h1 >>> 16;
3116
3117 HASHING_SEED = h1;
3118 }
3119
3120 /**
3121 * Cached value of the hashing algorithm result
3122 */
3123 private transient int hash32 = 0;
3124
3125 /**
3126 * Return a 32-bit hash code value for this object.
3127 * <p>
3128 * The general contract of {@code hash32} is:
3129 * <ul>
3130 * <li>Whenever it is invoked on the same object more than once during
3131 * an execution of a Java application, the {@code hash32} method
3132 * must consistently return the same integer, provided no information
3133 * used in {@code equals} comparisons on the object is modified.
3134 * This integer need not remain consistent from one execution of an
3135 * application to another execution of the same application.
3136 * <li>If two objects are equal according to the {@code equals(Object)}
3137 * method, then calling the {@code hash32} method on each of
3138 * the two objects must produce the same integer result.
3139 * <li>It is <em>not</em> required that if two objects are unequal
3140 * according to the {@link java.lang.Object#equals(java.lang.Object)}
3141 * method, then calling the {@code hash32} method on each of the
3142 * two objects must produce distinct integer results. However, the
3143 * programmer should be aware that producing distinct integer results
3144 * for unequal objects may improve the performance of hash tables.
3145 * </ul>
3146 * </p>
3147 * The hash value will never be zero.
3148 *
3149 * @return a hash code value for this object.
3150 * @see java.lang.Object#equals(java.lang.Object)
3151 */
3152 public int hash32() {
3153 int h = hash32;
3154 if (0 == h) {
3155 // harmless data race on hash32 here.
3156 h = sun.misc.Hashing.murmur3_32(HASHING_SEED, value, 0, value.length);
3157
3158 // ensure result is not zero to avoid recalcing
3159 h = (0 != h) ? h : 1;
3160
3161 hash32 = h;
3162 }
3163
3164 return h;
3165 }
3166
3167 }