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.regex.Matcher;
37 import java.util.regex.Pattern;
38 import java.util.regex.PatternSyntaxException;
39
40 /**
41 * The {@code String} class represents character strings. All
42 * string literals in Java programs, such as {@code "abc"}, are
43 * implemented as instances of this class.
44 * <p>
45 * Strings are constant; their values cannot be changed after they
46 * are created. String buffers support mutable strings.
47 * Because String objects are immutable they can be shared. For example:
48 * <p><blockquote><pre>
49 * String str = "abc";
50 * </pre></blockquote><p>
51 * is equivalent to:
52 * <p><blockquote><pre>
53 * char data[] = {'a', 'b', 'c'};
54 * String str = new String(data);
55 * </pre></blockquote><p>
56 * Here are some more examples of how strings can be used:
57 * <p><blockquote><pre>
58 * System.out.println("abc");
59 * String cde = "cde";
60 * System.out.println("abc" + cde);
61 * String c = "abc".substring(2,3);
62 * String d = cde.substring(1, 2);
63 * </pre></blockquote>
64 * <p>
65 * The class {@code String} includes methods for examining
66 * individual characters of the sequence, for comparing strings, for
67 * searching strings, for extracting substrings, and for creating a
68 * copy of a string with all characters translated to uppercase or to
69 * lowercase. Case mapping is based on the Unicode Standard version
70 * specified by the {@link java.lang.Character Character} class.
71 * <p>
72 * The Java language provides special support for the string
73 * concatenation operator ( + ), and for conversion of
74 * other objects to strings. String concatenation is implemented
75 * through the {@code StringBuilder}(or {@code StringBuffer})
76 * class and its {@code append} method.
77 * String conversions are implemented through the method
78 * {@code toString}, defined by {@code Object} and
79 * inherited by all classes in Java. For additional information on
80 * string concatenation and conversion, see Gosling, Joy, and Steele,
81 * <i>The Java Language Specification</i>.
82 *
83 * <p> Unless otherwise noted, passing a <tt>null</tt> argument to a constructor
84 * or method in this class will cause a {@link NullPointerException} to be
85 * thrown.
86 *
87 * <p>A {@code String} represents a string in the UTF-16 format
88 * in which <em>supplementary characters</em> are represented by <em>surrogate
89 * pairs</em> (see the section <a href="Character.html#unicode">Unicode
90 * Character Representations</a> in the {@code Character} class for
91 * more information).
92 * Index values refer to {@code char} code units, so a supplementary
93 * character uses two positions in a {@code String}.
94 * <p>The {@code String} class provides methods for dealing with
95 * Unicode code points (i.e., characters), in addition to those for
96 * dealing with Unicode code units (i.e., {@code char} values).
97 *
98 * @author Lee Boynton
99 * @author Arthur van Hoff
100 * @author Martin Buchholz
101 * @author Ulf Zibis
102 * @see java.lang.Object#toString()
103 * @see java.lang.StringBuffer
104 * @see java.lang.StringBuilder
105 * @see java.nio.charset.Charset
106 * @since JDK1.0
107 */
108
109 public final class String
110 implements java.io.Serializable, Comparable<String>, CharSequence {
111 /** The value is used for character storage. */
112 private final char value[];
113
114 /** Cache the hash code for the string */
115 private int hash; // Default to 0
116
117 /** use serialVersionUID from JDK 1.0.2 for interoperability */
118 private static final long serialVersionUID = -6849794470754667710L;
119
120 /**
121 * Class String is special cased within the Serialization Stream Protocol.
122 *
123 * A String instance is written initially into an ObjectOutputStream in the
124 * following format:
125 * <pre>
126 * {@code TC_STRING} (utf String)
127 * </pre>
128 * The String is written by method {@code DataOutput.writeUTF}.
129 * A new handle is generated to refer to all future references to the
130 * string instance within the stream.
131 */
132 private static final ObjectStreamField[] serialPersistentFields =
133 new ObjectStreamField[0];
134
135 /**
136 * Initializes a newly created {@code String} object so that it represents
137 * an empty character sequence. Note that use of this constructor is
138 * unnecessary since Strings are immutable.
139 */
140 public String() {
141 this.value = new char[0];
142 }
143
144 /**
145 * Initializes a newly created {@code String} object so that it represents
146 * the same sequence of characters as the argument; in other words, the
147 * newly created string is a copy of the argument string. Unless an
148 * explicit copy of {@code original} is needed, use of this constructor is
149 * unnecessary since Strings are immutable.
150 *
151 * @param original
152 * A {@code String}
153 */
154 public String(String original) {
155 this.value = original.value;
156 this.hash = original.hash;
157 }
158
159 /**
160 * Allocates a new {@code String} so that it represents the sequence of
161 * characters currently contained in the character array argument. The
162 * contents of the character array are copied; subsequent modification of
163 * the character array does not affect the newly created string.
164 *
165 * @param value
166 * The initial value of the string
167 */
168 public String(char value[]) {
169 this.value = Arrays.copyOf(value, value.length);
170 }
171
172 /**
173 * Allocates a new {@code String} that contains characters from a subarray
174 * of the character array argument. The {@code offset} argument is the
175 * index of the first character of the subarray and the {@code count}
176 * argument specifies the length of the subarray. The contents of the
177 * subarray are copied; subsequent modification of the character array does
178 * not affect the newly created string.
179 *
180 * @param value
181 * Array that is the source of characters
182 *
183 * @param offset
184 * The initial offset
185 *
186 * @param count
187 * The length
188 *
189 * @throws IndexOutOfBoundsException
190 * If the {@code offset} and {@code count} arguments index
191 * characters outside the bounds of the {@code value} array
192 */
193 public String(char value[], int offset, int count) {
194 if (offset < 0) {
195 throw new StringIndexOutOfBoundsException(offset);
196 }
197 if (count < 0) {
198 throw new StringIndexOutOfBoundsException(count);
199 }
200 // Note: offset or count might be near -1>>>1.
201 if (offset > value.length - count) {
202 throw new StringIndexOutOfBoundsException(offset + count);
203 }
204 this.value = Arrays.copyOfRange(value, offset, offset+count);
205 }
206
207 /**
208 * Allocates a new {@code String} that contains characters from a subarray
209 * of the <a href="Character.html#unicode">Unicode code point</a> array
210 * argument. The {@code offset} argument is the index of the first code
211 * point of the subarray and the {@code count} argument specifies the
212 * length of the subarray. The contents of the subarray are converted to
213 * {@code char}s; subsequent modification of the {@code int} array does not
214 * affect the newly created string.
215 *
216 * @param codePoints
217 * Array that is the source of Unicode code points
218 *
219 * @param offset
220 * The initial offset
221 *
222 * @param count
223 * The length
224 *
225 * @throws IllegalArgumentException
226 * If any invalid Unicode code point is found in {@code
227 * codePoints}
228 *
229 * @throws IndexOutOfBoundsException
230 * If the {@code offset} and {@code count} arguments index
231 * characters outside the bounds of the {@code codePoints} array
232 *
233 * @since 1.5
234 */
235 public String(int[] codePoints, int offset, int count) {
236 if (offset < 0) {
237 throw new StringIndexOutOfBoundsException(offset);
238 }
239 if (count < 0) {
240 throw new StringIndexOutOfBoundsException(count);
241 }
242 // Note: offset or count might be near -1>>>1.
243 if (offset > codePoints.length - count) {
244 throw new StringIndexOutOfBoundsException(offset + count);
245 }
246
247 final int end = offset + count;
248
249 // Pass 1: Compute precise size of char[]
250 int n = count;
251 for (int i = offset; i < end; i++) {
252 int c = codePoints[i];
253 if (Character.isBmpCodePoint(c))
254 continue;
255 else if (Character.isValidCodePoint(c))
256 n++;
257 else throw new IllegalArgumentException(Integer.toString(c));
258 }
259
260 // Pass 2: Allocate and fill in char[]
261 final char[] v = new char[n];
262
263 for (int i = offset, j = 0; i < end; i++, j++) {
264 int c = codePoints[i];
265 if (Character.isBmpCodePoint(c))
266 v[j] = (char)c;
267 else
268 Character.toSurrogates(c, v, j++);
269 }
270
271 this.value = v;
272 }
273
274 /**
275 * Allocates a new {@code String} constructed from a subarray of an array
276 * of 8-bit integer values.
277 *
278 * <p> The {@code offset} argument is the index of the first byte of the
279 * subarray, and the {@code count} argument specifies the length of the
280 * subarray.
281 *
282 * <p> Each {@code byte} in the subarray is converted to a {@code char} as
283 * specified in the method above.
284 *
285 * @deprecated This method does not properly convert bytes into characters.
286 * As of JDK 1.1, the preferred way to do this is via the
287 * {@code String} constructors that take a {@link
288 * java.nio.charset.Charset}, charset name, or that use the platform's
289 * default charset.
290 *
291 * @param ascii
292 * The bytes to be converted to characters
293 *
294 * @param hibyte
295 * The top 8 bits of each 16-bit Unicode code unit
296 *
297 * @param offset
298 * The initial offset
299 * @param count
300 * The length
301 *
302 * @throws IndexOutOfBoundsException
303 * If the {@code offset} or {@code count} argument is invalid
304 *
305 * @see #String(byte[], int)
306 * @see #String(byte[], int, int, java.lang.String)
307 * @see #String(byte[], int, int, java.nio.charset.Charset)
308 * @see #String(byte[], int, int)
309 * @see #String(byte[], java.lang.String)
310 * @see #String(byte[], java.nio.charset.Charset)
311 * @see #String(byte[])
312 */
313 @Deprecated
314 public String(byte ascii[], int hibyte, int offset, int count) {
315 checkBounds(ascii, offset, count);
316 char value[] = new char[count];
317
318 if (hibyte == 0) {
319 for (int i = count; i-- > 0;) {
320 value[i] = (char)(ascii[i + offset] & 0xff);
321 }
322 } else {
323 hibyte <<= 8;
324 for (int i = count; i-- > 0;) {
325 value[i] = (char)(hibyte | (ascii[i + offset] & 0xff));
326 }
327 }
328 this.value = value;
329 }
330
331 /**
332 * Allocates a new {@code String} containing characters constructed from
333 * an array of 8-bit integer values. Each character <i>c</i>in the
334 * resulting string is constructed from the corresponding component
335 * <i>b</i> in the byte array such that:
336 *
337 * <blockquote><pre>
338 * <b><i>c</i></b> == (char)(((hibyte & 0xff) << 8)
339 * | (<b><i>b</i></b> & 0xff))
340 * </pre></blockquote>
341 *
342 * @deprecated This method does not properly convert bytes into
343 * characters. As of JDK 1.1, the preferred way to do this is via the
344 * {@code String} constructors that take a {@link
345 * java.nio.charset.Charset}, charset name, or that use the platform's
346 * default charset.
347 *
348 * @param ascii
349 * The bytes to be converted to characters
350 *
351 * @param hibyte
352 * The top 8 bits of each 16-bit Unicode code unit
353 *
354 * @see #String(byte[], int, int, java.lang.String)
355 * @see #String(byte[], int, int, java.nio.charset.Charset)
356 * @see #String(byte[], int, int)
357 * @see #String(byte[], java.lang.String)
358 * @see #String(byte[], java.nio.charset.Charset)
359 * @see #String(byte[])
360 */
361 @Deprecated
362 public String(byte ascii[], int hibyte) {
363 this(ascii, hibyte, 0, ascii.length);
364 }
365
366 /* Common private utility method used to bounds check the byte array
367 * and requested offset & length values used by the String(byte[],..)
368 * constructors.
369 */
370 private static void checkBounds(byte[] bytes, int offset, int length) {
371 if (length < 0)
372 throw new StringIndexOutOfBoundsException(length);
373 if (offset < 0)
374 throw new StringIndexOutOfBoundsException(offset);
375 if (offset > bytes.length - length)
376 throw new StringIndexOutOfBoundsException(offset + length);
377 }
378
379 /**
380 * Constructs a new {@code String} by decoding the specified subarray of
381 * bytes using the specified charset. The length of the new {@code String}
382 * is a function of the charset, and hence may not be equal to the length
383 * of the subarray.
384 *
385 * <p> The behavior of this constructor when the given bytes are not valid
386 * in the given charset is unspecified. The {@link
387 * java.nio.charset.CharsetDecoder} class should be used when more control
388 * over the decoding process is required.
389 *
390 * @param bytes
391 * The bytes to be decoded into characters
392 *
393 * @param offset
394 * The index of the first byte to decode
395 *
396 * @param length
397 * The number of bytes to decode
398
399 * @param charsetName
400 * The name of a supported {@linkplain java.nio.charset.Charset
401 * charset}
402 *
403 * @throws UnsupportedEncodingException
404 * If the named charset is not supported
405 *
406 * @throws IndexOutOfBoundsException
407 * If the {@code offset} and {@code length} arguments index
408 * characters outside the bounds of the {@code bytes} array
409 *
410 * @since JDK1.1
411 */
412 public String(byte bytes[], int offset, int length, String charsetName)
413 throws UnsupportedEncodingException {
414 if (charsetName == null)
415 throw new NullPointerException("charsetName");
416 checkBounds(bytes, offset, length);
417 this.value = StringCoding.decode(charsetName, bytes, offset, length);
418 }
419
420 /**
421 * Constructs a new {@code String} by decoding the specified subarray of
422 * bytes using the specified {@linkplain java.nio.charset.Charset charset}.
423 * The length of the new {@code String} is a function of the charset, and
424 * hence may not be equal to the length of the subarray.
425 *
426 * <p> This method always replaces malformed-input and unmappable-character
427 * sequences with this charset's default replacement string. The {@link
428 * java.nio.charset.CharsetDecoder} class should be used when more control
429 * over the decoding process is required.
430 *
431 * @param bytes
432 * The bytes to be decoded into characters
433 *
434 * @param offset
435 * The index of the first byte to decode
436 *
437 * @param length
438 * The number of bytes to decode
439 *
440 * @param charset
441 * The {@linkplain java.nio.charset.Charset charset} to be used to
442 * decode the {@code bytes}
443 *
444 * @throws IndexOutOfBoundsException
445 * If the {@code offset} and {@code length} arguments index
446 * characters outside the bounds of the {@code bytes} array
447 *
448 * @since 1.6
449 */
450 public String(byte bytes[], int offset, int length, Charset charset) {
451 if (charset == null)
452 throw new NullPointerException("charset");
453 checkBounds(bytes, offset, length);
454 this.value = StringCoding.decode(charset, bytes, offset, length);
455 }
456
457 /**
458 * Constructs a new {@code String} by decoding the specified array of bytes
459 * using the specified {@linkplain java.nio.charset.Charset charset}. The
460 * length of the new {@code String} is a function of the charset, and hence
461 * may not be equal to the length of the byte array.
462 *
463 * <p> The behavior of this constructor when the given bytes are not valid
464 * in the given charset is unspecified. The {@link
465 * java.nio.charset.CharsetDecoder} class should be used when more control
466 * over the decoding process is required.
467 *
468 * @param bytes
469 * The bytes to be decoded into characters
470 *
471 * @param charsetName
472 * The name of a supported {@linkplain java.nio.charset.Charset
473 * charset}
474 *
475 * @throws UnsupportedEncodingException
476 * If the named charset is not supported
477 *
478 * @since JDK1.1
479 */
480 public String(byte bytes[], String charsetName)
481 throws UnsupportedEncodingException {
482 this(bytes, 0, bytes.length, charsetName);
483 }
484
485 /**
486 * Constructs a new {@code String} by decoding the specified array of
487 * bytes using the specified {@linkplain java.nio.charset.Charset charset}.
488 * The length of the new {@code String} is a function of the charset, and
489 * hence may not be equal to the length of the byte array.
490 *
491 * <p> This method always replaces malformed-input and unmappable-character
492 * sequences with this charset's default replacement string. The {@link
493 * java.nio.charset.CharsetDecoder} class should be used when more control
494 * over the decoding process is required.
495 *
496 * @param bytes
497 * The bytes to be decoded into characters
498 *
499 * @param charset
500 * The {@linkplain java.nio.charset.Charset charset} to be used to
501 * decode the {@code bytes}
502 *
503 * @since 1.6
504 */
505 public String(byte bytes[], Charset charset) {
506 this(bytes, 0, bytes.length, charset);
507 }
508
509 /**
510 * Constructs a new {@code String} by decoding the specified subarray of
511 * bytes using the platform's default charset. The length of the new
512 * {@code String} is a function of the charset, and hence may not be equal
513 * to the length of the subarray.
514 *
515 * <p> The behavior of this constructor when the given bytes are not valid
516 * in the default charset is unspecified. The {@link
517 * java.nio.charset.CharsetDecoder} class should be used when more control
518 * over the decoding process is required.
519 *
520 * @param bytes
521 * The bytes to be decoded into characters
522 *
523 * @param offset
524 * The index of the first byte to decode
525 *
526 * @param length
527 * The number of bytes to decode
528 *
529 * @throws IndexOutOfBoundsException
530 * If the {@code offset} and the {@code length} arguments index
531 * characters outside the bounds of the {@code bytes} array
532 *
533 * @since JDK1.1
534 */
535 public String(byte bytes[], int offset, int length) {
536 checkBounds(bytes, offset, length);
537 this.value = StringCoding.decode(bytes, offset, length);
538 }
539
540 /**
541 * Constructs a new {@code String} by decoding the specified array of bytes
542 * using the platform's default charset. The length of the new {@code
543 * String} is a function of the charset, and hence may not be equal to the
544 * length of the byte array.
545 *
546 * <p> The behavior of this constructor when the given bytes are not valid
547 * in the default charset is unspecified. The {@link
548 * java.nio.charset.CharsetDecoder} class should be used when more control
549 * over the decoding process is required.
550 *
551 * @param bytes
552 * The bytes to be decoded into characters
553 *
554 * @since JDK1.1
555 */
556 public String(byte bytes[]) {
557 this(bytes, 0, bytes.length);
558 }
559
560 /**
561 * Allocates a new string that contains the sequence of characters
562 * currently contained in the string buffer argument. The contents of the
563 * string buffer are copied; subsequent modification of the string buffer
564 * does not affect the newly created string.
565 *
566 * @param buffer
567 * A {@code StringBuffer}
568 */
569 public String(StringBuffer buffer) {
570 synchronized(buffer) {
571 this.value = Arrays.copyOf(buffer.getValue(), buffer.length());
572 }
573 }
574
575 /**
576 * Allocates a new string that contains the sequence of characters
577 * currently contained in the string builder argument. The contents of the
578 * string builder are copied; subsequent modification of the string builder
579 * does not affect the newly created string.
580 *
581 * <p> This constructor is provided to ease migration to {@code
582 * StringBuilder}. Obtaining a string from a string builder via the {@code
583 * toString} method is likely to run faster and is generally preferred.
584 *
585 * @param builder
586 * A {@code StringBuilder}
587 *
588 * @since 1.5
589 */
590 public String(StringBuilder builder) {
591 this.value = Arrays.copyOf(builder.getValue(), builder.length());
592 }
593
594 /*
595 * Package private constructor which shares value array for speed.
596 * this constructor is always expected to be called with share==true.
597 * a separate constructor is needed because we already have a public
598 * String(char[]) constructor that makes a copy of the given char[].
599 */
600 String(char[] value, boolean share) {
601 // assert share : "unshared not supported";
602 this.value = value;
603 }
604
605 /**
606 * Returns the length of this string.
607 * The length is equal to the number of <a href="Character.html#unicode">Unicode
608 * code units</a> in the string.
609 *
610 * @return the length of the sequence of characters represented by this
611 * object.
612 */
613 public int length() {
614 return value.length;
615 }
616
617 /**
618 * Returns {@code true} if, and only if, {@link #length()} is {@code 0}.
619 *
620 * @return {@code true} if {@link #length()} is {@code 0}, otherwise
621 * {@code false}
622 *
623 * @since 1.6
624 */
625 public boolean isEmpty() {
626 return value.length == 0;
627 }
628
629 /**
630 * Returns the {@code char} value at the
631 * specified index. An index ranges from {@code 0} to
632 * {@code length() - 1}. The first {@code char} value of the sequence
633 * is at index {@code 0}, the next at index {@code 1},
634 * and so on, as for array indexing.
635 *
636 * <p>If the {@code char} value specified by the index is a
637 * <a href="Character.html#unicode">surrogate</a>, the surrogate
638 * value is returned.
639 *
640 * @param index the index of the {@code char} value.
641 * @return the {@code char} value at the specified index of this string.
642 * The first {@code char} value is at index {@code 0}.
643 * @exception IndexOutOfBoundsException if the {@code index}
644 * argument is negative or not less than the length of this
645 * string.
646 */
647 public char charAt(int index) {
648 if ((index < 0) || (index >= value.length)) {
649 throw new StringIndexOutOfBoundsException(index);
650 }
651 return value[index];
652 }
653
654 /**
655 * Returns the character (Unicode code point) at the specified
656 * index. The index refers to {@code char} values
657 * (Unicode code units) and ranges from {@code 0} to
658 * {@link #length()}{@code - 1}.
659 *
660 * <p> If the {@code char} value specified at the given index
661 * is in the high-surrogate range, the following index is less
662 * than the length of this {@code String}, and the
663 * {@code char} value at the following index is in the
664 * low-surrogate range, then the supplementary code point
665 * corresponding to this surrogate pair is returned. Otherwise,
666 * the {@code char} value at the given index is returned.
667 *
668 * @param index the index to the {@code char} values
669 * @return the code point value of the character at the
670 * {@code index}
671 * @exception IndexOutOfBoundsException if the {@code index}
672 * argument is negative or not less than the length of this
673 * string.
674 * @since 1.5
675 */
676 public int codePointAt(int index) {
677 if ((index < 0) || (index >= value.length)) {
678 throw new StringIndexOutOfBoundsException(index);
679 }
680 return Character.codePointAtImpl(value, index, value.length);
681 }
682
683 /**
684 * Returns the character (Unicode code point) before the specified
685 * index. The index refers to {@code char} values
686 * (Unicode code units) and ranges from {@code 1} to {@link
687 * CharSequence#length() length}.
688 *
689 * <p> If the {@code char} value at {@code (index - 1)}
690 * is in the low-surrogate range, {@code (index - 2)} is not
691 * negative, and the {@code char} value at {@code (index -
692 * 2)} is in the high-surrogate range, then the
693 * supplementary code point value of the surrogate pair is
694 * returned. If the {@code char} value at {@code index -
695 * 1} is an unpaired low-surrogate or a high-surrogate, the
696 * surrogate value is returned.
697 *
698 * @param index the index following the code point that should be returned
699 * @return the Unicode code point value before the given index.
700 * @exception IndexOutOfBoundsException if the {@code index}
701 * argument is less than 1 or greater than the length
702 * of this string.
703 * @since 1.5
704 */
705 public int codePointBefore(int index) {
706 int i = index - 1;
707 if ((i < 0) || (i >= value.length)) {
708 throw new StringIndexOutOfBoundsException(index);
709 }
710 return Character.codePointBeforeImpl(value, index, 0);
711 }
712
713 /**
714 * Returns the number of Unicode code points in the specified text
715 * range of this {@code String}. The text range begins at the
716 * specified {@code beginIndex} and extends to the
717 * {@code char} at index {@code endIndex - 1}. Thus the
718 * length (in {@code char}s) of the text range is
719 * {@code endIndex-beginIndex}. Unpaired surrogates within
720 * the text range count as one code point each.
721 *
722 * @param beginIndex the index to the first {@code char} of
723 * the text range.
724 * @param endIndex the index after the last {@code char} of
725 * the text range.
726 * @return the number of Unicode code points in the specified text
727 * range
728 * @exception IndexOutOfBoundsException if the
729 * {@code beginIndex} is negative, or {@code endIndex}
730 * is larger than the length of this {@code String}, or
731 * {@code beginIndex} is larger than {@code endIndex}.
732 * @since 1.5
733 */
734 public int codePointCount(int beginIndex, int endIndex) {
735 if (beginIndex < 0 || endIndex > value.length || beginIndex > endIndex) {
736 throw new IndexOutOfBoundsException();
737 }
738 return Character.codePointCountImpl(value, beginIndex, endIndex - beginIndex);
739 }
740
741 /**
742 * Returns the index within this {@code String} that is
743 * offset from the given {@code index} by
744 * {@code codePointOffset} code points. Unpaired surrogates
745 * within the text range given by {@code index} and
746 * {@code codePointOffset} count as one code point each.
747 *
748 * @param index the index to be offset
749 * @param codePointOffset the offset in code points
750 * @return the index within this {@code String}
751 * @exception IndexOutOfBoundsException if {@code index}
752 * is negative or larger then the length of this
753 * {@code String}, or if {@code codePointOffset} is positive
754 * and the substring starting with {@code index} has fewer
755 * than {@code codePointOffset} code points,
756 * or if {@code codePointOffset} is negative and the substring
757 * before {@code index} has fewer than the absolute value
758 * of {@code codePointOffset} code points.
759 * @since 1.5
760 */
761 public int offsetByCodePoints(int index, int codePointOffset) {
762 if (index < 0 || index > value.length) {
763 throw new IndexOutOfBoundsException();
764 }
765 return Character.offsetByCodePointsImpl(value, 0, value.length,
766 index, codePointOffset);
767 }
768
769 /**
770 * Copy characters from this string into dst starting at dstBegin.
771 * This method doesn't perform any range checking.
772 */
773 void getChars(char dst[], int dstBegin) {
774 System.arraycopy(value, 0, dst, dstBegin, value.length);
775 }
776
777 /**
778 * Copies characters from this string into the destination character
779 * array.
780 * <p>
781 * The first character to be copied is at index {@code srcBegin};
782 * the last character to be copied is at index {@code srcEnd-1}
783 * (thus the total number of characters to be copied is
784 * {@code srcEnd-srcBegin}). The characters are copied into the
785 * subarray of {@code dst} starting at index {@code dstBegin}
786 * and ending at index:
787 * <p><blockquote><pre>
788 * dstbegin + (srcEnd-srcBegin) - 1
789 * </pre></blockquote>
790 *
791 * @param srcBegin index of the first character in the string
792 * to copy.
793 * @param srcEnd index after the last character in the string
794 * to copy.
795 * @param dst the destination array.
796 * @param dstBegin the start offset in the destination array.
797 * @exception IndexOutOfBoundsException If any of the following
798 * is true:
799 * <ul><li>{@code srcBegin} is negative.
800 * <li>{@code srcBegin} is greater than {@code srcEnd}
801 * <li>{@code srcEnd} is greater than the length of this
802 * string
803 * <li>{@code dstBegin} is negative
804 * <li>{@code dstBegin+(srcEnd-srcBegin)} is larger than
805 * {@code dst.length}</ul>
806 */
807 public void getChars(int srcBegin, int srcEnd, char dst[], int dstBegin) {
808 if (srcBegin < 0) {
809 throw new StringIndexOutOfBoundsException(srcBegin);
810 }
811 if (srcEnd > value.length) {
812 throw new StringIndexOutOfBoundsException(srcEnd);
813 }
814 if (srcBegin > srcEnd) {
815 throw new StringIndexOutOfBoundsException(srcEnd - srcBegin);
816 }
817 System.arraycopy(value, srcBegin, dst, dstBegin, srcEnd - srcBegin);
818 }
819
820 /**
821 * Copies characters from this string into the destination byte array. Each
822 * byte receives the 8 low-order bits of the corresponding character. The
823 * eight high-order bits of each character are not copied and do not
824 * participate in the transfer in any way.
825 *
826 * <p> The first character to be copied is at index {@code srcBegin}; the
827 * last character to be copied is at index {@code srcEnd-1}. The total
828 * number of characters to be copied is {@code srcEnd-srcBegin}. The
829 * characters, converted to bytes, are copied into the subarray of {@code
830 * dst} starting at index {@code dstBegin} and ending at index:
831 *
832 * <blockquote><pre>
833 * dstbegin + (srcEnd-srcBegin) - 1
834 * </pre></blockquote>
835 *
836 * @deprecated This method does not properly convert characters into
837 * bytes. As of JDK 1.1, the preferred way to do this is via the
838 * {@link #getBytes()} method, which uses the platform's default charset.
839 *
840 * @param srcBegin
841 * Index of the first character in the string to copy
842 *
843 * @param srcEnd
844 * Index after the last character in the string to copy
845 *
846 * @param dst
847 * The destination array
848 *
849 * @param dstBegin
850 * The start offset in the destination array
851 *
852 * @throws IndexOutOfBoundsException
853 * If any of the following is true:
854 * <ul>
855 * <li> {@code srcBegin} is negative
856 * <li> {@code srcBegin} is greater than {@code srcEnd}
857 * <li> {@code srcEnd} is greater than the length of this String
858 * <li> {@code dstBegin} is negative
859 * <li> {@code dstBegin+(srcEnd-srcBegin)} is larger than {@code
860 * dst.length}
861 * </ul>
862 */
863 @Deprecated
864 public void getBytes(int srcBegin, int srcEnd, byte dst[], int dstBegin) {
865 if (srcBegin < 0) {
866 throw new StringIndexOutOfBoundsException(srcBegin);
867 }
868 if (srcEnd > value.length) {
869 throw new StringIndexOutOfBoundsException(srcEnd);
870 }
871 if (srcBegin > srcEnd) {
872 throw new StringIndexOutOfBoundsException(srcEnd - srcBegin);
873 }
874 int j = dstBegin;
875 int n = srcEnd;
876 int i = srcBegin;
877 char[] val = value; /* avoid getfield opcode */
878
879 while (i < n) {
880 dst[j++] = (byte)val[i++];
881 }
882 }
883
884 /**
885 * Encodes this {@code String} into a sequence of bytes using the named
886 * charset, storing the result into a new byte array.
887 *
888 * <p> The behavior of this method when this string cannot be encoded in
889 * the given charset is unspecified. The {@link
890 * java.nio.charset.CharsetEncoder} class should be used when more control
891 * over the encoding process is required.
892 *
893 * @param charsetName
894 * The name of a supported {@linkplain java.nio.charset.Charset
895 * charset}
896 *
897 * @return The resultant byte array
898 *
899 * @throws UnsupportedEncodingException
900 * If the named charset is not supported
901 *
902 * @since JDK1.1
903 */
904 public byte[] getBytes(String charsetName)
905 throws UnsupportedEncodingException {
906 if (charsetName == null) throw new NullPointerException();
907 return StringCoding.encode(charsetName, value, 0, value.length);
908 }
909
910 /**
911 * Encodes this {@code String} into a sequence of bytes using the given
912 * {@linkplain java.nio.charset.Charset charset}, storing the result into a
913 * new byte array.
914 *
915 * <p> This method always replaces malformed-input and unmappable-character
916 * sequences with this charset's default replacement byte array. The
917 * {@link java.nio.charset.CharsetEncoder} class should be used when more
918 * control over the encoding process is required.
919 *
920 * @param charset
921 * The {@linkplain java.nio.charset.Charset} to be used to encode
922 * the {@code String}
923 *
924 * @return The resultant byte array
925 *
926 * @since 1.6
927 */
928 public byte[] getBytes(Charset charset) {
929 if (charset == null) throw new NullPointerException();
930 return StringCoding.encode(charset, value, 0, value.length);
931 }
932
933 /**
934 * Encodes this {@code String} into a sequence of bytes using the
935 * platform's default charset, storing the result into a new byte array.
936 *
937 * <p> The behavior of this method when this string cannot be encoded in
938 * the default charset is unspecified. The {@link
939 * java.nio.charset.CharsetEncoder} class should be used when more control
940 * over the encoding process is required.
941 *
942 * @return The resultant byte array
943 *
944 * @since JDK1.1
945 */
946 public byte[] getBytes() {
947 return StringCoding.encode(value, 0, value.length);
948 }
949
950 /**
951 * Compares this string to the specified object. The result is {@code
952 * true} if and only if the argument is not {@code null} and is a {@code
953 * String} object that represents the same sequence of characters as this
954 * object.
955 *
956 * @param anObject
957 * The object to compare this {@code String} against
958 *
959 * @return {@code true} if the given object represents a {@code String}
960 * equivalent to this string, {@code false} otherwise
961 *
962 * @see #compareTo(String)
963 * @see #equalsIgnoreCase(String)
964 */
965 public boolean equals(Object anObject) {
966 if (this == anObject) {
967 return true;
968 }
969 if (anObject instanceof String) {
970 String anotherString = (String) anObject;
971 int n = value.length;
972 if (n == anotherString.value.length) {
973 char v1[] = value;
974 char v2[] = anotherString.value;
975 int i = 0;
976 while (n-- != 0) {
977 if (v1[i] != v2[i])
978 return false;
979 i++;
980 }
981 return true;
982 }
983 }
984 return false;
985 }
986
987 /**
988 * Compares this string to the specified {@code StringBuffer}. The result
989 * is {@code true} if and only if this {@code String} represents the same
990 * sequence of characters as the specified {@code StringBuffer}. This method
991 * synchronizes on the {@code StringBuffer}.
992 *
993 * @param sb
994 * The {@code StringBuffer} to compare this {@code String} against
995 *
996 * @return {@code true} if this {@code String} represents the same
997 * sequence of characters as the specified {@code StringBuffer},
998 * {@code false} otherwise
999 *
1000 * @since 1.4
1001 */
1002 public boolean contentEquals(StringBuffer sb) {
1003 return contentEquals((CharSequence) sb);
1004 }
1005
1006 private boolean nonSyncContentEquals(AbstractStringBuilder sb) {
1007 char v1[] = value;
1008 char v2[] = sb.getValue();
1009 int i = 0;
1010 int n = value.length;
1011 while (n-- != 0) {
1012 if (v1[i] != v2[i]) {
1013 return false;
1014 }
1015 i++;
1016 }
1017 return true;
1018 }
1019
1020 /**
1021 * Compares this string to the specified {@code CharSequence}. The
1022 * result is {@code true} if and only if this {@code String} represents the
1023 * same sequence of char values as the specified sequence. Note that if the
1024 * {@code CharSequence} is a {@code StringBuffer} then the method
1025 * synchronizes on it.
1026 *
1027 * @param cs
1028 * The sequence to compare this {@code String} against
1029 *
1030 * @return {@code true} if this {@code String} represents the same
1031 * sequence of char values as the specified sequence, {@code
1032 * false} otherwise
1033 *
1034 * @since 1.5
1035 */
1036 public boolean contentEquals(CharSequence cs) {
1037 if (value.length != cs.length())
1038 return false;
1039 // Argument is a StringBuffer, StringBuilder
1040 if (cs instanceof AbstractStringBuilder) {
1041 if (cs instanceof StringBuffer) {
1042 synchronized(cs) {
1043 return nonSyncContentEquals((AbstractStringBuilder)cs);
1044 }
1045 } else {
1046 return nonSyncContentEquals((AbstractStringBuilder)cs);
1047 }
1048 }
1049 // Argument is a String
1050 if (cs.equals(this))
1051 return true;
1052 // Argument is a generic CharSequence
1053 char v1[] = value;
1054 int i = 0;
1055 int n = value.length;
1056 while (n-- != 0) {
1057 if (v1[i] != cs.charAt(i))
1058 return false;
1059 i++;
1060 }
1061 return true;
1062 }
1063
1064 /**
1065 * Compares this {@code String} to another {@code String}, ignoring case
1066 * considerations. Two strings are considered equal ignoring case if they
1067 * are of the same length and corresponding characters in the two strings
1068 * are equal ignoring case.
1069 *
1070 * <p> Two characters {@code c1} and {@code c2} are considered the same
1071 * ignoring case if at least one of the following is true:
1072 * <ul>
1073 * <li> The two characters are the same (as compared by the
1074 * {@code ==} operator)
1075 * <li> Applying the method {@link
1076 * java.lang.Character#toUpperCase(char)} to each character
1077 * produces the same result
1078 * <li> Applying the method {@link
1079 * java.lang.Character#toLowerCase(char)} to each character
1080 * produces the same result
1081 * </ul>
1082 *
1083 * @param anotherString
1084 * The {@code String} to compare this {@code String} against
1085 *
1086 * @return {@code true} if the argument is not {@code null} and it
1087 * represents an equivalent {@code String} ignoring case; {@code
1088 * false} otherwise
1089 *
1090 * @see #equals(Object)
1091 */
1092 public boolean equalsIgnoreCase(String anotherString) {
1093 return (this == anotherString) ? true
1094 : (anotherString != null)
1095 && (anotherString.value.length == value.length)
1096 && regionMatches(true, 0, anotherString, 0, value.length);
1097 }
1098
1099 /**
1100 * Compares two strings lexicographically.
1101 * The comparison is based on the Unicode value of each character in
1102 * the strings. The character sequence represented by this
1103 * {@code String} object is compared lexicographically to the
1104 * character sequence represented by the argument string. The result is
1105 * a negative integer if this {@code String} object
1106 * lexicographically precedes the argument string. The result is a
1107 * positive integer if this {@code String} object lexicographically
1108 * follows the argument string. The result is zero if the strings
1109 * are equal; {@code compareTo} returns {@code 0} exactly when
1110 * the {@link #equals(Object)} method would return {@code true}.
1111 * <p>
1112 * This is the definition of lexicographic ordering. If two strings are
1113 * different, then either they have different characters at some index
1114 * that is a valid index for both strings, or their lengths are different,
1115 * or both. If they have different characters at one or more index
1116 * positions, let <i>k</i> be the smallest such index; then the string
1117 * whose character at position <i>k</i> has the smaller value, as
1118 * determined by using the < operator, lexicographically precedes the
1119 * other string. In this case, {@code compareTo} returns the
1120 * difference of the two character values at position {@code k} in
1121 * the two string -- that is, the value:
1122 * <blockquote><pre>
1123 * this.charAt(k)-anotherString.charAt(k)
1124 * </pre></blockquote>
1125 * If there is no index position at which they differ, then the shorter
1126 * string lexicographically precedes the longer string. In this case,
1127 * {@code compareTo} returns the difference of the lengths of the
1128 * strings -- that is, the value:
1129 * <blockquote><pre>
1130 * this.length()-anotherString.length()
1131 * </pre></blockquote>
1132 *
1133 * @param anotherString the {@code String} to be compared.
1134 * @return the value {@code 0} if the argument string is equal to
1135 * this string; a value less than {@code 0} if this string
1136 * is lexicographically less than the string argument; and a
1137 * value greater than {@code 0} if this string is
1138 * lexicographically greater than the string argument.
1139 */
1140 public int compareTo(String anotherString) {
1141 int len1 = value.length;
1142 int len2 = anotherString.value.length;
1143 int lim = Math.min(len1, len2);
1144 char v1[] = value;
1145 char v2[] = anotherString.value;
1146
1147 int k = 0;
1148 while (k < lim) {
1149 char c1 = v1[k];
1150 char c2 = v2[k];
1151 if (c1 != c2) {
1152 return c1 - c2;
1153 }
1154 k++;
1155 }
1156 return len1 - len2;
1157 }
1158
1159 /**
1160 * A Comparator that orders {@code String} objects as by
1161 * {@code compareToIgnoreCase}. This comparator is serializable.
1162 * <p>
1163 * Note that this Comparator does <em>not</em> take locale into account,
1164 * and will result in an unsatisfactory ordering for certain locales.
1165 * The java.text package provides <em>Collators</em> to allow
1166 * locale-sensitive ordering.
1167 *
1168 * @see java.text.Collator#compare(String, String)
1169 * @since 1.2
1170 */
1171 public static final Comparator<String> CASE_INSENSITIVE_ORDER
1172 = new CaseInsensitiveComparator();
1173 private static class CaseInsensitiveComparator
1174 implements Comparator<String>, java.io.Serializable {
1175 // use serialVersionUID from JDK 1.2.2 for interoperability
1176 private static final long serialVersionUID = 8575799808933029326L;
1177
1178 public int compare(String s1, String s2) {
1179 int n1 = s1.length();
1180 int n2 = s2.length();
1181 int min = Math.min(n1, n2);
1182 for (int i = 0; i < min; i++) {
1183 char c1 = s1.charAt(i);
1184 char c2 = s2.charAt(i);
1185 if (c1 != c2) {
1186 c1 = Character.toUpperCase(c1);
1187 c2 = Character.toUpperCase(c2);
1188 if (c1 != c2) {
1189 c1 = Character.toLowerCase(c1);
1190 c2 = Character.toLowerCase(c2);
1191 if (c1 != c2) {
1192 // No overflow because of numeric promotion
1193 return c1 - c2;
1194 }
1195 }
1196 }
1197 }
1198 return n1 - n2;
1199 }
1200
1201 /** Replaces the de-serialized object. */
1202 private Object readResolve() { return CASE_INSENSITIVE_ORDER; }
1203 }
1204
1205 /**
1206 * Compares two strings lexicographically, ignoring case
1207 * differences. This method returns an integer whose sign is that of
1208 * calling {@code compareTo} with normalized versions of the strings
1209 * where case differences have been eliminated by calling
1210 * {@code Character.toLowerCase(Character.toUpperCase(character))} on
1211 * each character.
1212 * <p>
1213 * Note that this method does <em>not</em> take locale into account,
1214 * and will result in an unsatisfactory ordering for certain locales.
1215 * The java.text package provides <em>collators</em> to allow
1216 * locale-sensitive ordering.
1217 *
1218 * @param str the {@code String} to be compared.
1219 * @return a negative integer, zero, or a positive integer as the
1220 * specified String is greater than, equal to, or less
1221 * than this String, ignoring case considerations.
1222 * @see java.text.Collator#compare(String, String)
1223 * @since 1.2
1224 */
1225 public int compareToIgnoreCase(String str) {
1226 return CASE_INSENSITIVE_ORDER.compare(this, str);
1227 }
1228
1229 /**
1230 * Tests if two string regions are equal.
1231 * <p>
1232 * A substring of this {@code String} object is compared to a substring
1233 * of the argument other. The result is true if these substrings
1234 * represent identical character sequences. The substring of this
1235 * {@code String} object to be compared begins at index {@code toffset}
1236 * and has length {@code len}. The substring of other to be compared
1237 * begins at index {@code ooffset} and has length {@code len}. The
1238 * result is {@code false} if and only if at least one of the following
1239 * is true:
1240 * <ul><li>{@code toffset} is negative.
1241 * <li>{@code ooffset} is negative.
1242 * <li>{@code toffset+len} is greater than the length of this
1243 * {@code String} object.
1244 * <li>{@code ooffset+len} is greater than the length of the other
1245 * argument.
1246 * <li>There is some nonnegative integer <i>k</i> less than {@code len}
1247 * such that:
1248 * <code>this.charAt(toffset+<i>k</i>) != other.charAt(ooffset+<i>k</i>)</code>
1249 * </ul>
1250 *
1251 * @param toffset the starting offset of the subregion in this string.
1252 * @param other the string argument.
1253 * @param ooffset the starting offset of the subregion in the string
1254 * argument.
1255 * @param len the number of characters to compare.
1256 * @return {@code true} if the specified subregion of this string
1257 * exactly matches the specified subregion of the string argument;
1258 * {@code false} otherwise.
1259 */
1260 public boolean regionMatches(int toffset, String other, int ooffset,
1261 int len) {
1262 char ta[] = value;
1263 int to = toffset;
1264 char pa[] = other.value;
1265 int po = ooffset;
1266 // Note: toffset, ooffset, or len might be near -1>>>1.
1267 if ((ooffset < 0) || (toffset < 0)
1268 || (toffset > (long)value.length - len)
1269 || (ooffset > (long)other.value.length - len)) {
1270 return false;
1271 }
1272 while (len-- > 0) {
1273 if (ta[to++] != pa[po++]) {
1274 return false;
1275 }
1276 }
1277 return true;
1278 }
1279
1280 /**
1281 * Tests if two string regions are equal.
1282 * <p>
1283 * A substring of this {@code String} object is compared to a substring
1284 * of the argument {@code other}. The result is {@code true} if these
1285 * substrings represent character sequences that are the same, ignoring
1286 * case if and only if {@code ignoreCase} is true. The substring of
1287 * this {@code String} object to be compared begins at index
1288 * {@code toffset} and has length {@code len}. The substring of
1289 * {@code other} to be compared begins at index {@code ooffset} and
1290 * has length {@code len}. The result is {@code false} if and only if
1291 * at least one of the following is true:
1292 * <ul><li>{@code toffset} is negative.
1293 * <li>{@code ooffset} is negative.
1294 * <li>{@code toffset+len} is greater than the length of this
1295 * {@code String} object.
1296 * <li>{@code ooffset+len} is greater than the length of the other
1297 * argument.
1298 * <li>{@code ignoreCase} is {@code false} and there is some nonnegative
1299 * integer <i>k</i> less than {@code len} such that:
1300 * <blockquote><pre>
1301 * this.charAt(toffset+k) != other.charAt(ooffset+k)
1302 * </pre></blockquote>
1303 * <li>{@code ignoreCase} is {@code true} and there is some nonnegative
1304 * integer <i>k</i> less than {@code len} such that:
1305 * <blockquote><pre>
1306 * Character.toLowerCase(this.charAt(toffset+k)) !=
1307 Character.toLowerCase(other.charAt(ooffset+k))
1308 * </pre></blockquote>
1309 * and:
1310 * <blockquote><pre>
1311 * Character.toUpperCase(this.charAt(toffset+k)) !=
1312 * Character.toUpperCase(other.charAt(ooffset+k))
1313 * </pre></blockquote>
1314 * </ul>
1315 *
1316 * @param ignoreCase if {@code true}, ignore case when comparing
1317 * characters.
1318 * @param toffset the starting offset of the subregion in this
1319 * string.
1320 * @param other the string argument.
1321 * @param ooffset the starting offset of the subregion in the string
1322 * argument.
1323 * @param len the number of characters to compare.
1324 * @return {@code true} if the specified subregion of this string
1325 * matches the specified subregion of the string argument;
1326 * {@code false} otherwise. Whether the matching is exact
1327 * or case insensitive depends on the {@code ignoreCase}
1328 * argument.
1329 */
1330 public boolean regionMatches(boolean ignoreCase, int toffset,
1331 String other, int ooffset, int len) {
1332 char ta[] = value;
1333 int to = toffset;
1334 char pa[] = other.value;
1335 int po = ooffset;
1336 // Note: toffset, ooffset, or len might be near -1>>>1.
1337 if ((ooffset < 0) || (toffset < 0)
1338 || (toffset > (long)value.length - len)
1339 || (ooffset > (long)other.value.length - len)) {
1340 return false;
1341 }
1342 while (len-- > 0) {
1343 char c1 = ta[to++];
1344 char c2 = pa[po++];
1345 if (c1 == c2) {
1346 continue;
1347 }
1348 if (ignoreCase) {
1349 // If characters don't match but case may be ignored,
1350 // try converting both characters to uppercase.
1351 // If the results match, then the comparison scan should
1352 // continue.
1353 char u1 = Character.toUpperCase(c1);
1354 char u2 = Character.toUpperCase(c2);
1355 if (u1 == u2) {
1356 continue;
1357 }
1358 // Unfortunately, conversion to uppercase does not work properly
1359 // for the Georgian alphabet, which has strange rules about case
1360 // conversion. So we need to make one last check before
1361 // exiting.
1362 if (Character.toLowerCase(u1) == Character.toLowerCase(u2)) {
1363 continue;
1364 }
1365 }
1366 return false;
1367 }
1368 return true;
1369 }
1370
1371 /**
1372 * Tests if the substring of this string beginning at the
1373 * specified index starts with the specified prefix.
1374 *
1375 * @param prefix the prefix.
1376 * @param toffset where to begin looking in this string.
1377 * @return {@code true} if the character sequence represented by the
1378 * argument is a prefix of the substring of this object starting
1379 * at index {@code toffset}; {@code false} otherwise.
1380 * The result is {@code false} if {@code toffset} is
1381 * negative or greater than the length of this
1382 * {@code String} object; otherwise the result is the same
1383 * as the result of the expression
1384 * <pre>
1385 * this.substring(toffset).startsWith(prefix)
1386 * </pre>
1387 */
1388 public boolean startsWith(String prefix, int toffset) {
1389 char ta[] = value;
1390 int to = toffset;
1391 char pa[] = prefix.value;
1392 int po = 0;
1393 int pc = prefix.value.length;
1394 // Note: toffset might be near -1>>>1.
1395 if ((toffset < 0) || (toffset > value.length - pc)) {
1396 return false;
1397 }
1398 while (--pc >= 0) {
1399 if (ta[to++] != pa[po++]) {
1400 return false;
1401 }
1402 }
1403 return true;
1404 }
1405
1406 /**
1407 * Tests if this string starts with the specified prefix.
1408 *
1409 * @param prefix the prefix.
1410 * @return {@code true} if the character sequence represented by the
1411 * argument is a prefix of the character sequence represented by
1412 * this string; {@code false} otherwise.
1413 * Note also that {@code true} will be returned if the
1414 * argument is an empty string or is equal to this
1415 * {@code String} object as determined by the
1416 * {@link #equals(Object)} method.
1417 * @since 1. 0
1418 */
1419 public boolean startsWith(String prefix) {
1420 return startsWith(prefix, 0);
1421 }
1422
1423 /**
1424 * Tests if this string ends with the specified suffix.
1425 *
1426 * @param suffix the suffix.
1427 * @return {@code true} if the character sequence represented by the
1428 * argument is a suffix of the character sequence represented by
1429 * this object; {@code false} otherwise. Note that the
1430 * result will be {@code true} if the argument is the
1431 * empty string or is equal to this {@code String} object
1432 * as determined by the {@link #equals(Object)} method.
1433 */
1434 public boolean endsWith(String suffix) {
1435 return startsWith(suffix, value.length - suffix.value.length);
1436 }
1437
1438 /**
1439 * Returns a hash code for this string. The hash code for a
1440 * {@code String} object is computed as
1441 * <blockquote><pre>
1442 * s[0]*31^(n-1) + s[1]*31^(n-2) + ... + s[n-1]
1443 * </pre></blockquote>
1444 * using {@code int} arithmetic, where {@code s[i]} is the
1445 * <i>i</i>th character of the string, {@code n} is the length of
1446 * the string, and {@code ^} indicates exponentiation.
1447 * (The hash value of the empty string is zero.)
1448 *
1449 * @return a hash code value for this object.
1450 */
1451 public int hashCode() {
1452 int h = hash;
1453 if (h == 0 && value.length > 0) {
1454 char val[] = value;
1455
1456 for (int i = 0; i < value.length; i++) {
1457 h = 31 * h + val[i];
1458 }
1459 hash = h;
1460 }
1461 return h;
1462 }
1463
1464 /**
1465 * Returns the index within this string of the first occurrence of
1466 * the specified character. If a character with value
1467 * {@code ch} occurs in the character sequence represented by
1468 * this {@code String} object, then the index (in Unicode
1469 * code units) of the first such occurrence is returned. For
1470 * values of {@code ch} in the range from 0 to 0xFFFF
1471 * (inclusive), this is the smallest value <i>k</i> such that:
1472 * <blockquote><pre>
1473 * this.charAt(<i>k</i>) == ch
1474 * </pre></blockquote>
1475 * is true. For other values of {@code ch}, it is the
1476 * smallest value <i>k</i> such that:
1477 * <blockquote><pre>
1478 * this.codePointAt(<i>k</i>) == ch
1479 * </pre></blockquote>
1480 * is true. In either case, if no such character occurs in this
1481 * string, then {@code -1} is returned.
1482 *
1483 * @param ch a character (Unicode code point).
1484 * @return the index of the first occurrence of the character in the
1485 * character sequence represented by this object, or
1486 * {@code -1} if the character does not occur.
1487 */
1488 public int indexOf(int ch) {
1489 return indexOf(ch, 0);
1490 }
1491
1492 /**
1493 * Returns the index within this string of the first occurrence of the
1494 * specified character, starting the search at the specified index.
1495 * <p>
1496 * If a character with value {@code ch} occurs in the
1497 * character sequence represented by this {@code String}
1498 * object at an index no smaller than {@code fromIndex}, then
1499 * the index of the first such occurrence is returned. For values
1500 * of {@code ch} in the range from 0 to 0xFFFF (inclusive),
1501 * this is the smallest value <i>k</i> such that:
1502 * <blockquote><pre>
1503 * (this.charAt(<i>k</i>) == ch) {@code &&} (<i>k</i> >= fromIndex)
1504 * </pre></blockquote>
1505 * is true. For other values of {@code ch}, it is the
1506 * smallest value <i>k</i> such that:
1507 * <blockquote><pre>
1508 * (this.codePointAt(<i>k</i>) == ch) {@code &&} (<i>k</i> >= fromIndex)
1509 * </pre></blockquote>
1510 * is true. In either case, if no such character occurs in this
1511 * string at or after position {@code fromIndex}, then
1512 * {@code -1} is returned.
1513 *
1514 * <p>
1515 * There is no restriction on the value of {@code fromIndex}. If it
1516 * is negative, it has the same effect as if it were zero: this entire
1517 * string may be searched. If it is greater than the length of this
1518 * string, it has the same effect as if it were equal to the length of
1519 * this string: {@code -1} is returned.
1520 *
1521 * <p>All indices are specified in {@code char} values
1522 * (Unicode code units).
1523 *
1524 * @param ch a character (Unicode code point).
1525 * @param fromIndex the index to start the search from.
1526 * @return the index of the first occurrence of the character in the
1527 * character sequence represented by this object that is greater
1528 * than or equal to {@code fromIndex}, or {@code -1}
1529 * if the character does not occur.
1530 */
1531 public int indexOf(int ch, int fromIndex) {
1532 final int max = value.length;
1533 if (fromIndex < 0) {
1534 fromIndex = 0;
1535 } else if (fromIndex >= max) {
1536 // Note: fromIndex might be near -1>>>1.
1537 return -1;
1538 }
1539
1540 if (ch < Character.MIN_SUPPLEMENTARY_CODE_POINT) {
1541 // handle most cases here (ch is a BMP code point or a
1542 // negative value (invalid code point))
1543 final char[] value = this.value;
1544 for (int i = fromIndex; i < max; i++) {
1545 if (value[i] == ch) {
1546 return i;
1547 }
1548 }
1549 return -1;
1550 } else {
1551 return indexOfSupplementary(ch, fromIndex);
1552 }
1553 }
1554
1555 /**
1556 * Handles (rare) calls of indexOf with a supplementary character.
1557 */
1558 private int indexOfSupplementary(int ch, int fromIndex) {
1559 if (Character.isValidCodePoint(ch)) {
1560 final char[] value = this.value;
1561 final char hi = Character.highSurrogate(ch);
1562 final char lo = Character.lowSurrogate(ch);
1563 final int max = value.length - 1;
1564 for (int i = fromIndex; i < max; i++) {
1565 if (value[i] == hi && value[i + 1] == lo) {
1566 return i;
1567 }
1568 }
1569 }
1570 return -1;
1571 }
1572
1573 /**
1574 * Returns the index within this string of the last occurrence of
1575 * the specified character. For values of {@code ch} in the
1576 * range from 0 to 0xFFFF (inclusive), the index (in Unicode code
1577 * units) returned is the largest value <i>k</i> such that:
1578 * <blockquote><pre>
1579 * this.charAt(<i>k</i>) == ch
1580 * </pre></blockquote>
1581 * is true. For other values of {@code ch}, it is the
1582 * largest value <i>k</i> such that:
1583 * <blockquote><pre>
1584 * this.codePointAt(<i>k</i>) == ch
1585 * </pre></blockquote>
1586 * is true. In either case, if no such character occurs in this
1587 * string, then {@code -1} is returned. The
1588 * {@code String} is searched backwards starting at the last
1589 * character.
1590 *
1591 * @param ch a character (Unicode code point).
1592 * @return the index of the last occurrence of the character in the
1593 * character sequence represented by this object, or
1594 * {@code -1} if the character does not occur.
1595 */
1596 public int lastIndexOf(int ch) {
1597 return lastIndexOf(ch, value.length - 1);
1598 }
1599
1600 /**
1601 * Returns the index within this string of the last occurrence of
1602 * the specified character, searching backward starting at the
1603 * specified index. For values of {@code ch} in the range
1604 * from 0 to 0xFFFF (inclusive), the index returned is the largest
1605 * value <i>k</i> such that:
1606 * <blockquote><pre>
1607 * (this.charAt(<i>k</i>) == ch) {@code &&} (<i>k</i> <= fromIndex)
1608 * </pre></blockquote>
1609 * is true. For other values of {@code ch}, it is the
1610 * largest value <i>k</i> such that:
1611 * <blockquote><pre>
1612 * (this.codePointAt(<i>k</i>) == ch) {@code &&} (<i>k</i> <= fromIndex)
1613 * </pre></blockquote>
1614 * is true. In either case, if no such character occurs in this
1615 * string at or before position {@code fromIndex}, then
1616 * {@code -1} is returned.
1617 *
1618 * <p>All indices are specified in {@code char} values
1619 * (Unicode code units).
1620 *
1621 * @param ch a character (Unicode code point).
1622 * @param fromIndex the index to start the search from. There is no
1623 * restriction on the value of {@code fromIndex}. If it is
1624 * greater than or equal to the length of this string, it has
1625 * the same effect as if it were equal to one less than the
1626 * length of this string: this entire string may be searched.
1627 * If it is negative, it has the same effect as if it were -1:
1628 * -1 is returned.
1629 * @return the index of the last occurrence of the character in the
1630 * character sequence represented by this object that is less
1631 * than or equal to {@code fromIndex}, or {@code -1}
1632 * if the character does not occur before that point.
1633 */
1634 public int lastIndexOf(int ch, int fromIndex) {
1635 if (ch < Character.MIN_SUPPLEMENTARY_CODE_POINT) {
1636 // handle most cases here (ch is a BMP code point or a
1637 // negative value (invalid code point))
1638 final char[] value = this.value;
1639 int i = Math.min(fromIndex, value.length - 1);
1640 for (; i >= 0; i--) {
1641 if (value[i] == ch) {
1642 return i;
1643 }
1644 }
1645 return -1;
1646 } else {
1647 return lastIndexOfSupplementary(ch, fromIndex);
1648 }
1649 }
1650
1651 /**
1652 * Handles (rare) calls of lastIndexOf with a supplementary character.
1653 */
1654 private int lastIndexOfSupplementary(int ch, int fromIndex) {
1655 if (Character.isValidCodePoint(ch)) {
1656 final char[] value = this.value;
1657 char hi = Character.highSurrogate(ch);
1658 char lo = Character.lowSurrogate(ch);
1659 int i = Math.min(fromIndex, value.length - 2);
1660 for (; i >= 0; i--) {
1661 if (value[i] == hi && value[i + 1] == lo) {
1662 return i;
1663 }
1664 }
1665 }
1666 return -1;
1667 }
1668
1669 /**
1670 * Returns the index within this string of the first occurrence of the
1671 * specified substring.
1672 *
1673 * <p>The returned index is the smallest value <i>k</i> for which:
1674 * <blockquote><pre>
1675 * this.startsWith(str, <i>k</i>)
1676 * </pre></blockquote>
1677 * If no such value of <i>k</i> exists, then {@code -1} is returned.
1678 *
1679 * @param str the substring to search for.
1680 * @return the index of the first occurrence of the specified substring,
1681 * or {@code -1} if there is no such occurrence.
1682 */
1683 public int indexOf(String str) {
1684 return indexOf(str, 0);
1685 }
1686
1687 /**
1688 * Returns the index within this string of the first occurrence of the
1689 * specified substring, starting at the specified index.
1690 *
1691 * <p>The returned index is the smallest value <i>k</i> for which:
1692 * <blockquote><pre>
1693 * <i>k</i> >= fromIndex {@code &&} this.startsWith(str, <i>k</i>)
1694 * </pre></blockquote>
1695 * If no such value of <i>k</i> exists, then {@code -1} is returned.
1696 *
1697 * @param str the substring to search for.
1698 * @param fromIndex the index from which to start the search.
1699 * @return the index of the first occurrence of the specified substring,
1700 * starting at the specified index,
1701 * or {@code -1} if there is no such occurrence.
1702 */
1703 public int indexOf(String str, int fromIndex) {
1704 return indexOf(value, 0, value.length,
1705 str.value, 0, str.value.length, fromIndex);
1706 }
1707
1708 /**
1709 * Code shared by String and AbstractStringBuilder to do searches. The
1710 * source is the character array being searched, and the target
1711 * is the string being searched for.
1712 *
1713 * @param source the characters being searched.
1714 * @param sourceOffset offset of the source string.
1715 * @param sourceCount count of the source string.
1716 * @param target the characters being searched for.
1717 * @param fromIndex the index to begin searching from.
1718 */
1719 static int indexOf(char[] source, int sourceOffset, int sourceCount,
1720 String target, int fromIndex) {
1721 return indexOf(source, sourceOffset, sourceCount,
1722 target.value, 0, target.value.length,
1723 fromIndex);
1724 }
1725
1726 /**
1727 * Code shared by String and StringBuffer to do searches. The
1728 * source is the character array being searched, and the target
1729 * is the string being searched for.
1730 *
1731 * @param source the characters being searched.
1732 * @param sourceOffset offset of the source string.
1733 * @param sourceCount count of the source string.
1734 * @param target the characters being searched for.
1735 * @param targetOffset offset of the target string.
1736 * @param targetCount count of the target string.
1737 * @param fromIndex the index to begin searching from.
1738 */
1739 static int indexOf(char[] source, int sourceOffset, int sourceCount,
1740 char[] target, int targetOffset, int targetCount,
1741 int fromIndex) {
1742 if (fromIndex >= sourceCount) {
1743 return (targetCount == 0 ? sourceCount : -1);
1744 }
1745 if (fromIndex < 0) {
1746 fromIndex = 0;
1747 }
1748 if (targetCount == 0) {
1749 return fromIndex;
1750 }
1751
1752 char first = target[targetOffset];
1753 int max = sourceOffset + (sourceCount - targetCount);
1754
1755 for (int i = sourceOffset + fromIndex; i <= max; i++) {
1756 /* Look for first character. */
1757 if (source[i] != first) {
1758 while (++i <= max && source[i] != first);
1759 }
1760
1761 /* Found first character, now look at the rest of v2 */
1762 if (i <= max) {
1763 int j = i + 1;
1764 int end = j + targetCount - 1;
1765 for (int k = targetOffset + 1; j < end && source[j]
1766 == target[k]; j++, k++);
1767
1768 if (j == end) {
1769 /* Found whole string. */
1770 return i - sourceOffset;
1771 }
1772 }
1773 }
1774 return -1;
1775 }
1776
1777 /**
1778 * Returns the index within this string of the last occurrence of the
1779 * specified substring. The last occurrence of the empty string ""
1780 * is considered to occur at the index value {@code this.length()}.
1781 *
1782 * <p>The returned index is the largest value <i>k</i> for which:
1783 * <blockquote><pre>
1784 * this.startsWith(str, <i>k</i>)
1785 * </pre></blockquote>
1786 * If no such value of <i>k</i> exists, then {@code -1} is returned.
1787 *
1788 * @param str the substring to search for.
1789 * @return the index of the last occurrence of the specified substring,
1790 * or {@code -1} if there is no such occurrence.
1791 */
1792 public int lastIndexOf(String str) {
1793 return lastIndexOf(str, value.length);
1794 }
1795
1796 /**
1797 * Returns the index within this string of the last occurrence of the
1798 * specified substring, searching backward starting at the specified index.
1799 *
1800 * <p>The returned index is the largest value <i>k</i> for which:
1801 * <blockquote><pre>
1802 * <i>k</i> {@code <=} fromIndex {@code &&} this.startsWith(str, <i>k</i>)
1803 * </pre></blockquote>
1804 * If no such value of <i>k</i> exists, then {@code -1} is returned.
1805 *
1806 * @param str the substring to search for.
1807 * @param fromIndex the index to start the search from.
1808 * @return the index of the last occurrence of the specified substring,
1809 * searching backward from the specified index,
1810 * or {@code -1} if there is no such occurrence.
1811 */
1812 public int lastIndexOf(String str, int fromIndex) {
1813 return lastIndexOf(value, 0, value.length,
1814 str.value, 0, str.value.length, fromIndex);
1815 }
1816
1817 /**
1818 * Code shared by String and AbstractStringBuilder to do searches. The
1819 * source is the character array being searched, and the target
1820 * is the string being searched for.
1821 *
1822 * @param source the characters being searched.
1823 * @param sourceOffset offset of the source string.
1824 * @param sourceCount count of the source string.
1825 * @param target the characters being searched for.
1826 * @param fromIndex the index to begin searching from.
1827 */
1828 static int lastIndexOf(char[] source, int sourceOffset, int sourceCount,
1829 String target, int fromIndex) {
1830 return lastIndexOf(source, sourceOffset, sourceCount,
1831 target.value, 0, target.value.length,
1832 fromIndex);
1833 }
1834
1835 /**
1836 * Code shared by String and StringBuffer to do searches. The
1837 * source is the character array being searched, and the target
1838 * is the string being searched for.
1839 *
1840 * @param source the characters being searched.
1841 * @param sourceOffset offset of the source string.
1842 * @param sourceCount count of the source string.
1843 * @param target the characters being searched for.
1844 * @param targetOffset offset of the target string.
1845 * @param targetCount count of the target string.
1846 * @param fromIndex the index to begin searching from.
1847 */
1848 static int lastIndexOf(char[] source, int sourceOffset, int sourceCount,
1849 char[] target, int targetOffset, int targetCount,
1850 int fromIndex) {
1851 /*
1852 * Check arguments; return immediately where possible. For
1853 * consistency, don't check for null str.
1854 */
1855 int rightIndex = sourceCount - targetCount;
1856 if (fromIndex < 0) {
1857 return -1;
1858 }
1859 if (fromIndex > rightIndex) {
1860 fromIndex = rightIndex;
1861 }
1862 /* Empty string always matches. */
1863 if (targetCount == 0) {
1864 return fromIndex;
1865 }
1866
1867 int strLastIndex = targetOffset + targetCount - 1;
1868 char strLastChar = target[strLastIndex];
1869 int min = sourceOffset + targetCount - 1;
1870 int i = min + fromIndex;
1871
1872 startSearchForLastChar:
1873 while (true) {
1874 while (i >= min && source[i] != strLastChar) {
1875 i--;
1876 }
1877 if (i < min) {
1878 return -1;
1879 }
1880 int j = i - 1;
1881 int start = j - (targetCount - 1);
1882 int k = strLastIndex - 1;
1883
1884 while (j > start) {
1885 if (source[j--] != target[k--]) {
1886 i--;
1887 continue startSearchForLastChar;
1888 }
1889 }
1890 return start - sourceOffset + 1;
1891 }
1892 }
1893
1894 /**
1895 * Returns a new string that is a substring of this string. The
1896 * substring begins with the character at the specified index and
1897 * extends to the end of this string. <p>
1898 * Examples:
1899 * <blockquote><pre>
1900 * "unhappy".substring(2) returns "happy"
1901 * "Harbison".substring(3) returns "bison"
1902 * "emptiness".substring(9) returns "" (an empty string)
1903 * </pre></blockquote>
1904 *
1905 * @param beginIndex the beginning index, inclusive.
1906 * @return the specified substring.
1907 * @exception IndexOutOfBoundsException if
1908 * {@code beginIndex} is negative or larger than the
1909 * length of this {@code String} object.
1910 */
1911 public String substring(int beginIndex) {
1912 if (beginIndex < 0) {
1913 throw new StringIndexOutOfBoundsException(beginIndex);
1914 }
1915 int subLen = value.length - beginIndex;
1916 if (subLen < 0) {
1917 throw new StringIndexOutOfBoundsException(subLen);
1918 }
1919 return (beginIndex == 0) ? this : new String(value, beginIndex, subLen);
1920 }
1921
1922 /**
1923 * Returns a new string that is a substring of this string. The
1924 * substring begins at the specified {@code beginIndex} and
1925 * extends to the character at index {@code endIndex - 1}.
1926 * Thus the length of the substring is {@code endIndex-beginIndex}.
1927 * <p>
1928 * Examples:
1929 * <blockquote><pre>
1930 * "hamburger".substring(4, 8) returns "urge"
1931 * "smiles".substring(1, 5) returns "mile"
1932 * </pre></blockquote>
1933 *
1934 * @param beginIndex the beginning index, inclusive.
1935 * @param endIndex the ending index, exclusive.
1936 * @return the specified substring.
1937 * @exception IndexOutOfBoundsException if the
1938 * {@code beginIndex} is negative, or
1939 * {@code endIndex} is larger than the length of
1940 * this {@code String} object, or
1941 * {@code beginIndex} is larger than
1942 * {@code endIndex}.
1943 */
1944 public String substring(int beginIndex, int endIndex) {
1945 if (beginIndex < 0) {
1946 throw new StringIndexOutOfBoundsException(beginIndex);
1947 }
1948 if (endIndex > value.length) {
1949 throw new StringIndexOutOfBoundsException(endIndex);
1950 }
1951 int subLen = endIndex - beginIndex;
1952 if (subLen < 0) {
1953 throw new StringIndexOutOfBoundsException(subLen);
1954 }
1955 return ((beginIndex == 0) && (endIndex == value.length)) ? this
1956 : new String(value, beginIndex, subLen);
1957 }
1958
1959 /**
1960 * Returns a new character sequence that is a subsequence of this sequence.
1961 *
1962 * <p> An invocation of this method of the form
1963 *
1964 * <blockquote><pre>
1965 * str.subSequence(begin, end)</pre></blockquote>
1966 *
1967 * behaves in exactly the same way as the invocation
1968 *
1969 * <blockquote><pre>
1970 * str.substring(begin, end)</pre></blockquote>
1971 *
1972 * This method is defined so that the {@code String} class can implement
1973 * the {@link CharSequence} interface. </p>
1974 *
1975 * @param beginIndex the begin index, inclusive.
1976 * @param endIndex the end index, exclusive.
1977 * @return the specified subsequence.
1978 *
1979 * @throws IndexOutOfBoundsException
1980 * if {@code beginIndex} or {@code endIndex} is negative,
1981 * if {@code endIndex} is greater than {@code length()},
1982 * or if {@code beginIndex} is greater than {@code endIndex}
1983 *
1984 * @since 1.4
1985 * @spec JSR-51
1986 */
1987 public CharSequence subSequence(int beginIndex, int endIndex) {
1988 return this.substring(beginIndex, endIndex);
1989 }
1990
1991 /**
1992 * Concatenates the specified string to the end of this string.
1993 * <p>
1994 * If the length of the argument string is {@code 0}, then this
1995 * {@code String} object is returned. Otherwise, a new
1996 * {@code String} object is created, representing a character
1997 * sequence that is the concatenation of the character sequence
1998 * represented by this {@code String} object and the character
1999 * sequence represented by the argument string.<p>
2000 * Examples:
2001 * <blockquote><pre>
2002 * "cares".concat("s") returns "caress"
2003 * "to".concat("get").concat("her") returns "together"
2004 * </pre></blockquote>
2005 *
2006 * @param str the {@code String} that is concatenated to the end
2007 * of this {@code String}.
2008 * @return a string that represents the concatenation of this object's
2009 * characters followed by the string argument's characters.
2010 */
2011 public String concat(String str) {
2012 int otherLen = str.length();
2013 if (otherLen == 0) {
2014 return this;
2015 }
2016 int len = value.length;
2017 char buf[] = Arrays.copyOf(value, len + otherLen);
2018 str.getChars(buf, len);
2019 return new String(buf, true);
2020 }
2021
2022 /**
2023 * Returns a new string resulting from replacing all occurrences of
2024 * {@code oldChar} in this string with {@code newChar}.
2025 * <p>
2026 * If the character {@code oldChar} does not occur in the
2027 * character sequence represented by this {@code String} object,
2028 * then a reference to this {@code String} object is returned.
2029 * Otherwise, a new {@code String} object is created that
2030 * represents a character sequence identical to the character sequence
2031 * represented by this {@code String} object, except that every
2032 * occurrence of {@code oldChar} is replaced by an occurrence
2033 * of {@code newChar}.
2034 * <p>
2035 * Examples:
2036 * <blockquote><pre>
2037 * "mesquite in your cellar".replace('e', 'o')
2038 * returns "mosquito in your collar"
2039 * "the war of baronets".replace('r', 'y')
2040 * returns "the way of bayonets"
2041 * "sparring with a purple porpoise".replace('p', 't')
2042 * returns "starring with a turtle tortoise"
2043 * "JonL".replace('q', 'x') returns "JonL" (no change)
2044 * </pre></blockquote>
2045 *
2046 * @param oldChar the old character.
2047 * @param newChar the new character.
2048 * @return a string derived from this string by replacing every
2049 * occurrence of {@code oldChar} with {@code newChar}.
2050 */
2051 public String replace(char oldChar, char newChar) {
2052 if (oldChar != newChar) {
2053 int len = value.length;
2054 int i = -1;
2055 char[] val = value; /* avoid getfield opcode */
2056
2057 while (++i < len) {
2058 if (val[i] == oldChar) {
2059 break;
2060 }
2061 }
2062 if (i < len) {
2063 char buf[] = new char[len];
2064 for (int j = 0; j < i; j++) {
2065 buf[j] = val[j];
2066 }
2067 while (i < len) {
2068 char c = val[i];
2069 buf[i] = (c == oldChar) ? newChar : c;
2070 i++;
2071 }
2072 return new String(buf, true);
2073 }
2074 }
2075 return this;
2076 }
2077
2078 /**
2079 * Tells whether or not this string matches the given <a
2080 * href="../util/regex/Pattern.html#sum">regular expression</a>.
2081 *
2082 * <p> An invocation of this method of the form
2083 * <i>str</i>{@code .matches(}<i>regex</i>{@code )} yields exactly the
2084 * same result as the expression
2085 *
2086 * <blockquote>
2087 * {@link java.util.regex.Pattern}.{@link java.util.regex.Pattern#matches(String,CharSequence)
2088 * matches(<i>regex</i>, <i>str</i>)}
2089 * </blockquote>
2090 *
2091 * @param regex
2092 * the regular expression to which this string is to be matched
2093 *
2094 * @return {@code true} if, and only if, this string matches the
2095 * given regular expression
2096 *
2097 * @throws PatternSyntaxException
2098 * if the regular expression's syntax is invalid
2099 *
2100 * @see java.util.regex.Pattern
2101 *
2102 * @since 1.4
2103 * @spec JSR-51
2104 */
2105 public boolean matches(String regex) {
2106 return Pattern.matches(regex, this);
2107 }
2108
2109 /**
2110 * Returns true if and only if this string contains the specified
2111 * sequence of char values.
2112 *
2113 * @param s the sequence to search for
2114 * @return true if this string contains {@code s}, false otherwise
2115 * @throws NullPointerException if {@code s} is {@code null}
2116 * @since 1.5
2117 */
2118 public boolean contains(CharSequence s) {
2119 return indexOf(s.toString()) > -1;
2120 }
2121
2122 /**
2123 * Replaces the first substring of this string that matches the given <a
2124 * href="../util/regex/Pattern.html#sum">regular expression</a> with the
2125 * given replacement.
2126 *
2127 * <p> An invocation of this method of the form
2128 * <i>str</i>{@code .replaceFirst(}<i>regex</i>{@code ,} <i>repl</i>{@code )}
2129 * yields exactly the same result as the expression
2130 *
2131 * <blockquote>
2132 * <code>
2133 * {@link java.util.regex.Pattern}.{@link
2134 * java.util.regex.Pattern#compile compile}(<i>regex</i>).{@link
2135 * java.util.regex.Pattern#matcher(java.lang.CharSequence) matcher}(<i>str</i>).{@link
2136 * java.util.regex.Matcher#replaceFirst replaceFirst}(<i>repl</i>)
2137 * </code>
2138 * </blockquote>
2139 *
2140 *<p>
2141 * Note that backslashes ({@code \}) and dollar signs ({@code $}) in the
2142 * replacement string may cause the results to be different than if it were
2143 * being treated as a literal replacement string; see
2144 * {@link java.util.regex.Matcher#replaceFirst}.
2145 * Use {@link java.util.regex.Matcher#quoteReplacement} to suppress the special
2146 * meaning of these characters, if desired.
2147 *
2148 * @param regex
2149 * the regular expression to which this string is to be matched
2150 * @param replacement
2151 * the string to be substituted for the first match
2152 *
2153 * @return The resulting {@code String}
2154 *
2155 * @throws PatternSyntaxException
2156 * if the regular expression's syntax is invalid
2157 *
2158 * @see java.util.regex.Pattern
2159 *
2160 * @since 1.4
2161 * @spec JSR-51
2162 */
2163 public String replaceFirst(String regex, String replacement) {
2164 return Pattern.compile(regex).matcher(this).replaceFirst(replacement);
2165 }
2166
2167 /**
2168 * Replaces each substring of this string that matches the given <a
2169 * href="../util/regex/Pattern.html#sum">regular expression</a> with the
2170 * given replacement.
2171 *
2172 * <p> An invocation of this method of the form
2173 * <i>str</i>{@code .replaceAll(}<i>regex</i>{@code ,} <i>repl</i>{@code )}
2174 * yields exactly the same result as the expression
2175 *
2176 * <blockquote>
2177 * <code>
2178 * {@link java.util.regex.Pattern}.{@link
2179 * java.util.regex.Pattern#compile compile}(<i>regex</i>).{@link
2180 * java.util.regex.Pattern#matcher(java.lang.CharSequence) matcher}(<i>str</i>).{@link
2181 * java.util.regex.Matcher#replaceAll replaceAll}(<i>repl</i>)
2182 * </code>
2183 * </blockquote>
2184 *
2185 *<p>
2186 * Note that backslashes ({@code \}) and dollar signs ({@code $}) in the
2187 * replacement string may cause the results to be different than if it were
2188 * being treated as a literal replacement string; see
2189 * {@link java.util.regex.Matcher#replaceAll Matcher.replaceAll}.
2190 * Use {@link java.util.regex.Matcher#quoteReplacement} to suppress the special
2191 * meaning of these characters, if desired.
2192 *
2193 * @param regex
2194 * the regular expression to which this string is to be matched
2195 * @param replacement
2196 * the string to be substituted for each match
2197 *
2198 * @return The resulting {@code String}
2199 *
2200 * @throws PatternSyntaxException
2201 * if the regular expression's syntax is invalid
2202 *
2203 * @see java.util.regex.Pattern
2204 *
2205 * @since 1.4
2206 * @spec JSR-51
2207 */
2208 public String replaceAll(String regex, String replacement) {
2209 return Pattern.compile(regex).matcher(this).replaceAll(replacement);
2210 }
2211
2212 /**
2213 * Replaces each substring of this string that matches the literal target
2214 * sequence with the specified literal replacement sequence. The
2215 * replacement proceeds from the beginning of the string to the end, for
2216 * example, replacing "aa" with "b" in the string "aaa" will result in
2217 * "ba" rather than "ab".
2218 *
2219 * @param target The sequence of char values to be replaced
2220 * @param replacement The replacement sequence of char values
2221 * @return The resulting string
2222 * @throws NullPointerException if {@code target} or
2223 * {@code replacement} is {@code null}.
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 * @throws NullPointerException
2837 * If the {@code format} is {@code null}
2838 *
2839 * @return A formatted string
2840 *
2841 * @see java.util.Formatter
2842 * @since 1.5
2843 */
2844 public static String format(String format, Object... args) {
2845 return new Formatter().format(format, args).toString();
2846 }
2847
2848 /**
2849 * Returns a formatted string using the specified locale, format string,
2850 * and arguments.
2851 *
2852 * @param l
2853 * The {@linkplain java.util.Locale locale} to apply during
2854 * formatting. If {@code l} is {@code null} then no localization
2855 * is applied.
2856 *
2857 * @param format
2858 * A <a href="../util/Formatter.html#syntax">format string</a>
2859 *
2860 * @param args
2861 * Arguments referenced by the format specifiers in the format
2862 * string. If there are more arguments than format specifiers, the
2863 * extra arguments are ignored. The number of arguments is
2864 * variable and may be zero. The maximum number of arguments is
2865 * limited by the maximum dimension of a Java array as defined by
2866 * <cite>The Java™ Virtual Machine Specification</cite>.
2867 * The behaviour on a
2868 * {@code null} argument depends on the <a
2869 * href="../util/Formatter.html#syntax">conversion</a>.
2870 *
2871 * @throws java.util.IllegalFormatException
2872 * If a format string contains an illegal syntax, a format
2873 * specifier that is incompatible with the given arguments,
2874 * insufficient arguments given the format string, or other
2875 * illegal conditions. For specification of all possible
2876 * formatting errors, see the <a
2877 * href="../util/Formatter.html#detail">Details</a> section of the
2878 * formatter class specification
2879 *
2880 * @throws NullPointerException
2881 * If the {@code format} is {@code null}
2882 *
2883 * @return A formatted string
2884 *
2885 * @see java.util.Formatter
2886 * @since 1.5
2887 */
2888 public static String format(Locale l, String format, Object... args) {
2889 return new Formatter(l).format(format, args).toString();
2890 }
2891
2892 /**
2893 * Returns the string representation of the {@code Object} argument.
2894 *
2895 * @param obj an {@code Object}.
2896 * @return if the argument is {@code null}, then a string equal to
2897 * {@code "null"}; otherwise, the value of
2898 * {@code obj.toString()} is returned.
2899 * @see java.lang.Object#toString()
2900 */
2901 public static String valueOf(Object obj) {
2902 return (obj == null) ? "null" : obj.toString();
2903 }
2904
2905 /**
2906 * Returns the string representation of the {@code char} array
2907 * argument. The contents of the character array are copied; subsequent
2908 * modification of the character array does not affect the newly
2909 * created string.
2910 *
2911 * @param data a {@code char} array.
2912 * @return a newly allocated string representing the same sequence of
2913 * characters contained in the character array argument.
2914 */
2915 public static String valueOf(char data[]) {
2916 return new String(data);
2917 }
2918
2919 /**
2920 * Returns the string representation of a specific subarray of the
2921 * {@code char} array argument.
2922 * <p>
2923 * The {@code offset} argument is the index of the first
2924 * character of the subarray. The {@code count} argument
2925 * specifies the length of the subarray. The contents of the subarray
2926 * are copied; subsequent modification of the character array does not
2927 * affect the newly created string.
2928 *
2929 * @param data the character array.
2930 * @param offset the initial offset into the value of the
2931 * {@code String}.
2932 * @param count the length of the value of the {@code String}.
2933 * @return a string representing the sequence of characters contained
2934 * in the subarray of the character array argument.
2935 * @exception IndexOutOfBoundsException if {@code offset} is
2936 * negative, or {@code count} is negative, or
2937 * {@code offset+count} is larger than
2938 * {@code data.length}.
2939 */
2940 public static String valueOf(char data[], int offset, int count) {
2941 return new String(data, offset, count);
2942 }
2943
2944 /**
2945 * Returns a String that represents the character sequence in the
2946 * array specified.
2947 *
2948 * @param data the character array.
2949 * @param offset initial offset of the subarray.
2950 * @param count length of the subarray.
2951 * @return a {@code String} that contains the characters of the
2952 * specified subarray of the character array.
2953 */
2954 public static String copyValueOf(char data[], int offset, int count) {
2955 // All public String constructors now copy the data.
2956 return new String(data, offset, count);
2957 }
2958
2959 /**
2960 * Returns a String that represents the character sequence in the
2961 * array specified.
2962 *
2963 * @param data the character array.
2964 * @return a {@code String} that contains the characters of the
2965 * character array.
2966 */
2967 public static String copyValueOf(char data[]) {
2968 return new String(data);
2969 }
2970
2971 /**
2972 * Returns the string representation of the {@code boolean} argument.
2973 *
2974 * @param b a {@code boolean}.
2975 * @return if the argument is {@code true}, a string equal to
2976 * {@code "true"} is returned; otherwise, a string equal to
2977 * {@code "false"} is returned.
2978 */
2979 public static String valueOf(boolean b) {
2980 return b ? "true" : "false";
2981 }
2982
2983 /**
2984 * Returns the string representation of the {@code char}
2985 * argument.
2986 *
2987 * @param c a {@code char}.
2988 * @return a string of length {@code 1} containing
2989 * as its single character the argument {@code c}.
2990 */
2991 public static String valueOf(char c) {
2992 char data[] = {c};
2993 return new String(data, true);
2994 }
2995
2996 /**
2997 * Returns the string representation of the {@code int} argument.
2998 * <p>
2999 * The representation is exactly the one returned by the
3000 * {@code Integer.toString} method of one argument.
3001 *
3002 * @param i an {@code int}.
3003 * @return a string representation of the {@code int} argument.
3004 * @see java.lang.Integer#toString(int, int)
3005 */
3006 public static String valueOf(int i) {
3007 return Integer.toString(i);
3008 }
3009
3010 /**
3011 * Returns the string representation of the {@code long} argument.
3012 * <p>
3013 * The representation is exactly the one returned by the
3014 * {@code Long.toString} method of one argument.
3015 *
3016 * @param l a {@code long}.
3017 * @return a string representation of the {@code long} argument.
3018 * @see java.lang.Long#toString(long)
3019 */
3020 public static String valueOf(long l) {
3021 return Long.toString(l);
3022 }
3023
3024 /**
3025 * Returns the string representation of the {@code float} argument.
3026 * <p>
3027 * The representation is exactly the one returned by the
3028 * {@code Float.toString} method of one argument.
3029 *
3030 * @param f a {@code float}.
3031 * @return a string representation of the {@code float} argument.
3032 * @see java.lang.Float#toString(float)
3033 */
3034 public static String valueOf(float f) {
3035 return Float.toString(f);
3036 }
3037
3038 /**
3039 * Returns the string representation of the {@code double} argument.
3040 * <p>
3041 * The representation is exactly the one returned by the
3042 * {@code Double.toString} method of one argument.
3043 *
3044 * @param d a {@code double}.
3045 * @return a string representation of the {@code double} argument.
3046 * @see java.lang.Double#toString(double)
3047 */
3048 public static String valueOf(double d) {
3049 return Double.toString(d);
3050 }
3051
3052 /**
3053 * Returns a canonical representation for the string object.
3054 * <p>
3055 * A pool of strings, initially empty, is maintained privately by the
3056 * class {@code String}.
3057 * <p>
3058 * When the intern method is invoked, if the pool already contains a
3059 * string equal to this {@code String} object as determined by
3060 * the {@link #equals(Object)} method, then the string from the pool is
3061 * returned. Otherwise, this {@code String} object is added to the
3062 * pool and a reference to this {@code String} object is returned.
3063 * <p>
3064 * It follows that for any two strings {@code s} and {@code t},
3065 * {@code s.intern() == t.intern()} is {@code true}
3066 * if and only if {@code s.equals(t)} is {@code true}.
3067 * <p>
3068 * All literal strings and string-valued constant expressions are
3069 * interned. String literals are defined in section 3.10.5 of the
3070 * <cite>The Java™ Language Specification</cite>.
3071 *
3072 * @return a string that has the same contents as this string, but is
3073 * guaranteed to be from a pool of unique strings.
3074 */
3075 public native String intern();
3076
3077 /**
3078 * Seed value used for each alternative hash calculated.
3079 */
3080 private static final int HASHING_SEED;
3081
3082 static {
3083 long nanos = System.nanoTime();
3084 long now = System.currentTimeMillis();
3085 int SEED_MATERIAL[] = {
3086 System.identityHashCode(String.class),
3087 System.identityHashCode(System.class),
3088 (int) (nanos >>> 32),
3089 (int) nanos,
3090 (int) (now >>> 32),
3091 (int) now,
3092 (int) (System.nanoTime() >>> 2)
3093 };
3094
3095 // Use murmur3 to scramble the seeding material.
3096 // Inline implementation to avoid loading classes
3097 int h1 = 0;
3098
3099 // body
3100 for(int k1 : SEED_MATERIAL) {
3101 k1 *= 0xcc9e2d51;
3102 k1 = (k1 << 15) | (k1 >>> 17);
3103 k1 *= 0x1b873593;
3104
3105 h1 ^= k1;
3106 h1 = (h1 << 13) | (h1 >>> 19);
3107 h1 = h1 * 5 + 0xe6546b64;
3108 }
3109
3110 // tail (always empty, as body is always 32-bit chunks)
3111
3112 // finalization
3113
3114 h1 ^= SEED_MATERIAL.length * 4;
3115
3116 // finalization mix force all bits of a hash block to avalanche
3117 h1 ^= h1 >>> 16;
3118 h1 *= 0x85ebca6b;
3119 h1 ^= h1 >>> 13;
3120 h1 *= 0xc2b2ae35;
3121 h1 ^= h1 >>> 16;
3122
3123 HASHING_SEED = h1;
3124 }
3125
3126 /**
3127 * Cached value of the hashing algorithm result
3128 */
3129 private transient int hash32 = 0;
3130
3131 /**
3132 * Return a 32-bit hash code value for this object.
3133 * <p>
3134 * The general contract of {@code hash32} is:
3135 * <ul>
3136 * <li>Whenever it is invoked on the same object more than once during
3137 * an execution of a Java application, the {@code hash32} method
3138 * must consistently return the same integer, provided no information
3139 * used in {@code equals} comparisons on the object is modified.
3140 * This integer need not remain consistent from one execution of an
3141 * application to another execution of the same application.
3142 * <li>If two objects are equal according to the {@code equals(Object)}
3143 * method, then calling the {@code hash32} method on each of
3144 * the two objects must produce the same integer result.
3145 * <li>It is <em>not</em> required that if two objects are unequal
3146 * according to the {@link java.lang.Object#equals(java.lang.Object)}
3147 * method, then calling the {@code hash32} method on each of the
3148 * two objects must produce distinct integer results. However, the
3149 * programmer should be aware that producing distinct integer results
3150 * for unequal objects may improve the performance of hash tables.
3151 * </ul>
3152 * </p>
3153 * The hash value will never be zero.
3154 *
3155 * @return a hash code value for this object.
3156 * @see java.lang.Object#equals(java.lang.Object)
3157 */
3158 public int hash32() {
3159 int h = hash32;
3160 if (0 == h) {
3161 // harmless data race on hash32 here.
3162 h = sun.misc.Hashing.murmur3_32(HASHING_SEED, value, 0, value.length);
3163
3164 // ensure result is not zero to avoid recalcing
3165 h = (0 != h) ? h : 1;
3166
3167 hash32 = h;
3168 }
3169
3170 return h;
3171 }
3172
3173 }