1 /*
2 * Copyright (c) 1994, 2010, 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</code> class represents character strings. All
42 * string literals in Java programs, such as <code>"abc"</code>, 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</code> 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</code>(or <code>StringBuffer</code>)
76 * class and its <code>append</code> method.
77 * String conversions are implemented through the method
78 * <code>toString</code>, defined by <code>Object</code> 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</code> 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</code> class for
91 * more information).
92 * Index values refer to <code>char</code> code units, so a supplementary
93 * character uses two positions in a <code>String</code>.
94 * <p>The <code>String</code> 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</code> 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 {
112 /** The value is used for character storage. */
113 private final char value[];
114
115 /** The offset is the first index of the storage that is used. */
116 private final int offset;
117
118 /** The count is the number of characters in the String. */
119 private final int count;
120
121 /** Cache the hash code for the string */
122 private int hash; // Default to 0
123
124 /** use serialVersionUID from JDK 1.0.2 for interoperability */
125 private static final long serialVersionUID = -6849794470754667710L;
126
127 /**
128 * Class String is special cased within the Serialization Stream Protocol.
129 *
130 * A String instance is written initially into an ObjectOutputStream in the
131 * following format:
132 * <pre>
133 * <code>TC_STRING</code> (utf String)
134 * </pre>
135 * The String is written by method <code>DataOutput.writeUTF</code>.
136 * A new handle is generated to refer to all future references to the
137 * string instance within the stream.
138 */
139 private static final ObjectStreamField[] serialPersistentFields =
140 new ObjectStreamField[0];
141
142 /**
143 * Initializes a newly created {@code String} object so that it represents
144 * an empty character sequence. Note that use of this constructor is
145 * unnecessary since Strings are immutable.
146 */
147 public String() {
148 this.offset = 0;
149 this.count = 0;
150 this.value = new char[0];
151 }
152
153 /**
154 * Initializes a newly created {@code String} object so that it represents
155 * the same sequence of characters as the argument; in other words, the
156 * newly created string is a copy of the argument string. Unless an
157 * explicit copy of {@code original} is needed, use of this constructor is
158 * unnecessary since Strings are immutable.
159 *
160 * @param original
161 * A {@code String}
162 */
163 public String(String original) {
164 int size = original.count;
165 char[] originalValue = original.value;
166 char[] v;
167 if (originalValue.length > size) {
168 // The array representing the String is bigger than the new
169 // String itself. Perhaps this constructor is being called
170 // in order to trim the baggage, so make a copy of the array.
171 int off = original.offset;
172 v = Arrays.copyOfRange(originalValue, off, off+size);
173 } else {
174 // The array representing the String is the same
175 // size as the String, so no point in making a copy.
176 v = originalValue;
177 }
178 this.offset = 0;
179 this.count = size;
180 this.value = v;
181 }
182
183 /**
184 * Allocates a new {@code String} so that it represents the sequence of
185 * characters currently contained in the character array argument. The
186 * contents of the character array are copied; subsequent modification of
187 * the character array does not affect the newly created string.
188 *
189 * @param value
190 * The initial value of the string
191 */
192 public String(char value[]) {
193 int size = value.length;
194 this.offset = 0;
195 this.count = size;
196 this.value = Arrays.copyOf(value, size);
197 }
198
199 /**
200 * Allocates a new {@code String} that contains characters from a subarray
201 * of the character array argument. The {@code offset} argument is the
202 * index of the first character of the subarray and the {@code count}
203 * argument specifies the length of the subarray. The contents of the
204 * subarray are copied; subsequent modification of the character array does
205 * not affect the newly created string.
206 *
207 * @param value
208 * Array that is the source of characters
209 *
210 * @param offset
211 * The initial offset
212 *
213 * @param count
214 * The length
215 *
216 * @throws IndexOutOfBoundsException
217 * If the {@code offset} and {@code count} arguments index
218 * characters outside the bounds of the {@code value} array
219 */
220 public String(char value[], int offset, int count) {
221 if (offset < 0) {
222 throw new StringIndexOutOfBoundsException(offset);
223 }
224 if (count < 0) {
225 throw new StringIndexOutOfBoundsException(count);
226 }
227 // Note: offset or count might be near -1>>>1.
228 if (offset > value.length - count) {
229 throw new StringIndexOutOfBoundsException(offset + count);
230 }
231 this.offset = 0;
232 this.count = count;
233 this.value = Arrays.copyOfRange(value, offset, offset+count);
234 }
235
236 /**
237 * Allocates a new {@code String} that contains characters from a subarray
238 * of the <a href="Character.html#unicode">Unicode code point</a> array
239 * argument. The {@code offset} argument is the index of the first code
240 * point of the subarray and the {@code count} argument specifies the
241 * length of the subarray. The contents of the subarray are converted to
242 * {@code char}s; subsequent modification of the {@code int} array does not
243 * affect the newly created string.
244 *
245 * @param codePoints
246 * Array that is the source of Unicode code points
247 *
248 * @param offset
249 * The initial offset
250 *
251 * @param count
252 * The length
253 *
254 * @throws IllegalArgumentException
255 * If any invalid Unicode code point is found in {@code
256 * codePoints}
257 *
258 * @throws IndexOutOfBoundsException
259 * If the {@code offset} and {@code count} arguments index
260 * characters outside the bounds of the {@code codePoints} array
261 *
262 * @since 1.5
263 */
264 public String(int[] codePoints, int offset, int count) {
265 if (offset < 0) {
266 throw new StringIndexOutOfBoundsException(offset);
267 }
268 if (count < 0) {
269 throw new StringIndexOutOfBoundsException(count);
270 }
271 // Note: offset or count might be near -1>>>1.
272 if (offset > codePoints.length - count) {
273 throw new StringIndexOutOfBoundsException(offset + count);
274 }
275
276 final int end = offset + count;
277
278 // Pass 1: Compute precise size of char[]
279 int n = count;
280 for (int i = offset; i < end; i++) {
281 int c = codePoints[i];
282 if (Character.isBmpCodePoint(c))
283 continue;
284 else if (Character.isValidCodePoint(c))
285 n++;
286 else throw new IllegalArgumentException(Integer.toString(c));
287 }
288
289 // Pass 2: Allocate and fill in char[]
290 final char[] v = new char[n];
291
292 for (int i = offset, j = 0; i < end; i++, j++) {
293 int c = codePoints[i];
294 if (Character.isBmpCodePoint(c))
295 v[j] = (char) c;
296 else
297 Character.toSurrogates(c, v, j++);
298 }
299
300 this.value = v;
301 this.count = n;
302 this.offset = 0;
303 }
304
305 /**
306 * Allocates a new {@code String} constructed from a subarray of an array
307 * of 8-bit integer values.
308 *
309 * <p> The {@code offset} argument is the index of the first byte of the
310 * subarray, and the {@code count} argument specifies the length of the
311 * subarray.
312 *
313 * <p> Each {@code byte} in the subarray is converted to a {@code char} as
314 * specified in the method above.
315 *
316 * @deprecated This method does not properly convert bytes into characters.
317 * As of JDK 1.1, the preferred way to do this is via the
318 * {@code String} constructors that take a {@link
319 * java.nio.charset.Charset}, charset name, or that use the platform's
320 * default charset.
321 *
322 * @param ascii
323 * The bytes to be converted to characters
324 *
325 * @param hibyte
326 * The top 8 bits of each 16-bit Unicode code unit
327 *
328 * @param offset
329 * The initial offset
330 * @param count
331 * The length
332 *
333 * @throws IndexOutOfBoundsException
334 * If the {@code offset} or {@code count} argument is invalid
335 *
336 * @see #String(byte[], int)
337 * @see #String(byte[], int, int, java.lang.String)
338 * @see #String(byte[], int, int, java.nio.charset.Charset)
339 * @see #String(byte[], int, int)
340 * @see #String(byte[], java.lang.String)
341 * @see #String(byte[], java.nio.charset.Charset)
342 * @see #String(byte[])
343 */
344 @Deprecated
345 public String(byte ascii[], int hibyte, int offset, int count) {
346 checkBounds(ascii, offset, count);
347 char value[] = new char[count];
348
349 if (hibyte == 0) {
350 for (int i = count ; i-- > 0 ;) {
351 value[i] = (char) (ascii[i + offset] & 0xff);
352 }
353 } else {
354 hibyte <<= 8;
355 for (int i = count ; i-- > 0 ;) {
356 value[i] = (char) (hibyte | (ascii[i + offset] & 0xff));
357 }
358 }
359 this.offset = 0;
360 this.count = count;
361 this.value = value;
362 }
363
364 /**
365 * Allocates a new {@code String} containing characters constructed from
366 * an array of 8-bit integer values. Each character <i>c</i>in the
367 * resulting string is constructed from the corresponding component
368 * <i>b</i> in the byte array such that:
369 *
370 * <blockquote><pre>
371 * <b><i>c</i></b> == (char)(((hibyte & 0xff) << 8)
372 * | (<b><i>b</i></b> & 0xff))
373 * </pre></blockquote>
374 *
375 * @deprecated This method does not properly convert bytes into
376 * characters. As of JDK 1.1, the preferred way to do this is via the
377 * {@code String} constructors that take a {@link
378 * java.nio.charset.Charset}, charset name, or that use the platform's
379 * default charset.
380 *
381 * @param ascii
382 * The bytes to be converted to characters
383 *
384 * @param hibyte
385 * The top 8 bits of each 16-bit Unicode code unit
386 *
387 * @see #String(byte[], int, int, java.lang.String)
388 * @see #String(byte[], int, int, java.nio.charset.Charset)
389 * @see #String(byte[], int, int)
390 * @see #String(byte[], java.lang.String)
391 * @see #String(byte[], java.nio.charset.Charset)
392 * @see #String(byte[])
393 */
394 @Deprecated
395 public String(byte ascii[], int hibyte) {
396 this(ascii, hibyte, 0, ascii.length);
397 }
398
399 /* Common private utility method used to bounds check the byte array
400 * and requested offset & length values used by the String(byte[],..)
401 * constructors.
402 */
403 private static void checkBounds(byte[] bytes, int offset, int length) {
404 if (length < 0)
405 throw new StringIndexOutOfBoundsException(length);
406 if (offset < 0)
407 throw new StringIndexOutOfBoundsException(offset);
408 if (offset > bytes.length - length)
409 throw new StringIndexOutOfBoundsException(offset + length);
410 }
411
412 /**
413 * Constructs a new {@code String} by decoding the specified subarray of
414 * bytes using the specified charset. The length of the new {@code String}
415 * is a function of the charset, and hence may not be equal to the length
416 * of the subarray.
417 *
418 * <p> The behavior of this constructor when the given bytes are not valid
419 * in the given charset is unspecified. The {@link
420 * java.nio.charset.CharsetDecoder} class should be used when more control
421 * over the decoding process is required.
422 *
423 * @param bytes
424 * The bytes to be decoded into characters
425 *
426 * @param offset
427 * The index of the first byte to decode
428 *
429 * @param length
430 * The number of bytes to decode
431
432 * @param charsetName
433 * The name of a supported {@linkplain java.nio.charset.Charset
434 * charset}
435 *
436 * @throws UnsupportedEncodingException
437 * If the named charset is not supported
438 *
439 * @throws IndexOutOfBoundsException
440 * If the {@code offset} and {@code length} arguments index
441 * characters outside the bounds of the {@code bytes} array
442 *
443 * @since JDK1.1
444 */
445 public String(byte bytes[], int offset, int length, String charsetName)
446 throws UnsupportedEncodingException
447 {
448 if (charsetName == null)
449 throw new NullPointerException("charsetName");
450 checkBounds(bytes, offset, length);
451 char[] v = StringCoding.decode(charsetName, bytes, offset, length);
452 this.offset = 0;
453 this.count = v.length;
454 this.value = v;
455 }
456
457 /**
458 * Constructs a new {@code String} by decoding the specified subarray of
459 * bytes using the specified {@linkplain java.nio.charset.Charset charset}.
460 * The length of the new {@code String} is a function of the charset, and
461 * hence may not be equal to the length of the subarray.
462 *
463 * <p> This method always replaces malformed-input and unmappable-character
464 * sequences with this charset's default replacement string. 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 offset
472 * The index of the first byte to decode
473 *
474 * @param length
475 * The number of bytes to decode
476 *
477 * @param charset
478 * The {@linkplain java.nio.charset.Charset charset} to be used to
479 * decode the {@code bytes}
480 *
481 * @throws IndexOutOfBoundsException
482 * If the {@code offset} and {@code length} arguments index
483 * characters outside the bounds of the {@code bytes} array
484 *
485 * @since 1.6
486 */
487 public String(byte bytes[], int offset, int length, Charset charset) {
488 if (charset == null)
489 throw new NullPointerException("charset");
490 checkBounds(bytes, offset, length);
491 char[] v = StringCoding.decode(charset, bytes, offset, length);
492 this.offset = 0;
493 this.count = v.length;
494 this.value = v;
495 }
496
497 /**
498 * Constructs a new {@code String} by decoding the specified array of bytes
499 * using the specified {@linkplain java.nio.charset.Charset charset}. The
500 * length of the new {@code String} is a function of the charset, and hence
501 * may not be equal to the length of the byte array.
502 *
503 * <p> The behavior of this constructor when the given bytes are not valid
504 * in the given charset is unspecified. The {@link
505 * java.nio.charset.CharsetDecoder} class should be used when more control
506 * over the decoding process is required.
507 *
508 * @param bytes
509 * The bytes to be decoded into characters
510 *
511 * @param charsetName
512 * The name of a supported {@linkplain java.nio.charset.Charset
513 * charset}
514 *
515 * @throws UnsupportedEncodingException
516 * If the named charset is not supported
517 *
518 * @since JDK1.1
519 */
520 public String(byte bytes[], String charsetName)
521 throws UnsupportedEncodingException
522 {
523 this(bytes, 0, bytes.length, charsetName);
524 }
525
526 /**
527 * Constructs a new {@code String} by decoding the specified array of
528 * bytes using the specified {@linkplain java.nio.charset.Charset charset}.
529 * The length of the new {@code String} is a function of the charset, and
530 * hence may not be equal to the length of the byte array.
531 *
532 * <p> This method always replaces malformed-input and unmappable-character
533 * sequences with this charset's default replacement string. The {@link
534 * java.nio.charset.CharsetDecoder} class should be used when more control
535 * over the decoding process is required.
536 *
537 * @param bytes
538 * The bytes to be decoded into characters
539 *
540 * @param charset
541 * The {@linkplain java.nio.charset.Charset charset} to be used to
542 * decode the {@code bytes}
543 *
544 * @since 1.6
545 */
546 public String(byte bytes[], Charset charset) {
547 this(bytes, 0, bytes.length, charset);
548 }
549
550 /**
551 * Constructs a new {@code String} by decoding the specified subarray of
552 * bytes using the platform's default charset. The length of the new
553 * {@code String} is a function of the charset, and hence may not be equal
554 * to the length of the subarray.
555 *
556 * <p> The behavior of this constructor when the given bytes are not valid
557 * in the default charset is unspecified. The {@link
558 * java.nio.charset.CharsetDecoder} class should be used when more control
559 * over the decoding process is required.
560 *
561 * @param bytes
562 * The bytes to be decoded into characters
563 *
564 * @param offset
565 * The index of the first byte to decode
566 *
567 * @param length
568 * The number of bytes to decode
569 *
570 * @throws IndexOutOfBoundsException
571 * If the {@code offset} and the {@code length} arguments index
572 * characters outside the bounds of the {@code bytes} array
573 *
574 * @since JDK1.1
575 */
576 public String(byte bytes[], int offset, int length) {
577 checkBounds(bytes, offset, length);
578 char[] v = StringCoding.decode(bytes, offset, length);
579 this.offset = 0;
580 this.count = v.length;
581 this.value = v;
582 }
583
584 /**
585 * Constructs a new {@code String} by decoding the specified array of bytes
586 * using the platform's default charset. The length of the new {@code
587 * String} is a function of the charset, and hence may not be equal to the
588 * length of the byte array.
589 *
590 * <p> The behavior of this constructor when the given bytes are not valid
591 * in the default charset is unspecified. The {@link
592 * java.nio.charset.CharsetDecoder} class should be used when more control
593 * over the decoding process is required.
594 *
595 * @param bytes
596 * The bytes to be decoded into characters
597 *
598 * @since JDK1.1
599 */
600 public String(byte bytes[]) {
601 this(bytes, 0, bytes.length);
602 }
603
604 /**
605 * Allocates a new string that contains the sequence of characters
606 * currently contained in the string buffer argument. The contents of the
607 * string buffer are copied; subsequent modification of the string buffer
608 * does not affect the newly created string.
609 *
610 * @param buffer
611 * A {@code StringBuffer}
612 */
613 public String(StringBuffer buffer) {
614 String result = buffer.toString();
615 this.value = result.value;
616 this.count = result.count;
617 this.offset = result.offset;
618 }
619
620 /**
621 * Allocates a new string that contains the sequence of characters
622 * currently contained in the string builder argument. The contents of the
623 * string builder are copied; subsequent modification of the string builder
624 * does not affect the newly created string.
625 *
626 * <p> This constructor is provided to ease migration to {@code
627 * StringBuilder}. Obtaining a string from a string builder via the {@code
628 * toString} method is likely to run faster and is generally preferred.
629 *
630 * @param builder
631 * A {@code StringBuilder}
632 *
633 * @since 1.5
634 */
635 public String(StringBuilder builder) {
636 String result = builder.toString();
637 this.value = result.value;
638 this.count = result.count;
639 this.offset = result.offset;
640 }
641
642
643 // Package private constructor which shares value array for speed.
644 String(int offset, int count, char value[]) {
645 this.value = value;
646 this.offset = offset;
647 this.count = count;
648 }
649
650 /**
651 * Returns the length of this string.
652 * The length is equal to the number of <a href="Character.html#unicode">Unicode
653 * code units</a> in the string.
654 *
655 * @return the length of the sequence of characters represented by this
656 * object.
657 */
658 public int length() {
659 return count;
660 }
661
662 /**
663 * Returns <tt>true</tt> if, and only if, {@link #length()} is <tt>0</tt>.
664 *
665 * @return <tt>true</tt> if {@link #length()} is <tt>0</tt>, otherwise
666 * <tt>false</tt>
667 *
668 * @since 1.6
669 */
670 public boolean isEmpty() {
671 return count == 0;
672 }
673
674 /**
675 * Returns the <code>char</code> value at the
676 * specified index. An index ranges from <code>0</code> to
677 * <code>length() - 1</code>. The first <code>char</code> value of the sequence
678 * is at index <code>0</code>, the next at index <code>1</code>,
679 * and so on, as for array indexing.
680 *
681 * <p>If the <code>char</code> value specified by the index is a
682 * <a href="Character.html#unicode">surrogate</a>, the surrogate
683 * value is returned.
684 *
685 * @param index the index of the <code>char</code> value.
686 * @return the <code>char</code> value at the specified index of this string.
687 * The first <code>char</code> value is at index <code>0</code>.
688 * @exception IndexOutOfBoundsException if the <code>index</code>
689 * argument is negative or not less than the length of this
690 * string.
691 */
692 public char charAt(int index) {
693 if ((index < 0) || (index >= count)) {
694 throw new StringIndexOutOfBoundsException(index);
695 }
696 return value[index + offset];
697 }
698
699 /**
700 * Returns the character (Unicode code point) at the specified
701 * index. The index refers to <code>char</code> values
702 * (Unicode code units) and ranges from <code>0</code> to
703 * {@link #length()}<code> - 1</code>.
704 *
705 * <p> If the <code>char</code> value specified at the given index
706 * is in the high-surrogate range, the following index is less
707 * than the length of this <code>String</code>, and the
708 * <code>char</code> value at the following index is in the
709 * low-surrogate range, then the supplementary code point
710 * corresponding to this surrogate pair is returned. Otherwise,
711 * the <code>char</code> value at the given index is returned.
712 *
713 * @param index the index to the <code>char</code> values
714 * @return the code point value of the character at the
715 * <code>index</code>
716 * @exception IndexOutOfBoundsException if the <code>index</code>
717 * argument is negative or not less than the length of this
718 * string.
719 * @since 1.5
720 */
721 public int codePointAt(int index) {
722 if ((index < 0) || (index >= count)) {
723 throw new StringIndexOutOfBoundsException(index);
724 }
725 return Character.codePointAtImpl(value, offset + index, offset + count);
726 }
727
728 /**
729 * Returns the character (Unicode code point) before the specified
730 * index. The index refers to <code>char</code> values
731 * (Unicode code units) and ranges from <code>1</code> to {@link
732 * CharSequence#length() length}.
733 *
734 * <p> If the <code>char</code> value at <code>(index - 1)</code>
735 * is in the low-surrogate range, <code>(index - 2)</code> is not
736 * negative, and the <code>char</code> value at <code>(index -
737 * 2)</code> is in the high-surrogate range, then the
738 * supplementary code point value of the surrogate pair is
739 * returned. If the <code>char</code> value at <code>index -
740 * 1</code> is an unpaired low-surrogate or a high-surrogate, the
741 * surrogate value is returned.
742 *
743 * @param index the index following the code point that should be returned
744 * @return the Unicode code point value before the given index.
745 * @exception IndexOutOfBoundsException if the <code>index</code>
746 * argument is less than 1 or greater than the length
747 * of this string.
748 * @since 1.5
749 */
750 public int codePointBefore(int index) {
751 int i = index - 1;
752 if ((i < 0) || (i >= count)) {
753 throw new StringIndexOutOfBoundsException(index);
754 }
755 return Character.codePointBeforeImpl(value, offset + index, offset);
756 }
757
758 /**
759 * Returns the number of Unicode code points in the specified text
760 * range of this <code>String</code>. The text range begins at the
761 * specified <code>beginIndex</code> and extends to the
762 * <code>char</code> at index <code>endIndex - 1</code>. Thus the
763 * length (in <code>char</code>s) of the text range is
764 * <code>endIndex-beginIndex</code>. Unpaired surrogates within
765 * the text range count as one code point each.
766 *
767 * @param beginIndex the index to the first <code>char</code> of
768 * the text range.
769 * @param endIndex the index after the last <code>char</code> of
770 * the text range.
771 * @return the number of Unicode code points in the specified text
772 * range
773 * @exception IndexOutOfBoundsException if the
774 * <code>beginIndex</code> is negative, or <code>endIndex</code>
775 * is larger than the length of this <code>String</code>, or
776 * <code>beginIndex</code> is larger than <code>endIndex</code>.
777 * @since 1.5
778 */
779 public int codePointCount(int beginIndex, int endIndex) {
780 if (beginIndex < 0 || endIndex > count || beginIndex > endIndex) {
781 throw new IndexOutOfBoundsException();
782 }
783 return Character.codePointCountImpl(value, offset+beginIndex, endIndex-beginIndex);
784 }
785
786 /**
787 * Returns the index within this <code>String</code> that is
788 * offset from the given <code>index</code> by
789 * <code>codePointOffset</code> code points. Unpaired surrogates
790 * within the text range given by <code>index</code> and
791 * <code>codePointOffset</code> count as one code point each.
792 *
793 * @param index the index to be offset
794 * @param codePointOffset the offset in code points
795 * @return the index within this <code>String</code>
796 * @exception IndexOutOfBoundsException if <code>index</code>
797 * is negative or larger then the length of this
798 * <code>String</code>, or if <code>codePointOffset</code> is positive
799 * and the substring starting with <code>index</code> has fewer
800 * than <code>codePointOffset</code> code points,
801 * or if <code>codePointOffset</code> is negative and the substring
802 * before <code>index</code> has fewer than the absolute value
803 * of <code>codePointOffset</code> code points.
804 * @since 1.5
805 */
806 public int offsetByCodePoints(int index, int codePointOffset) {
807 if (index < 0 || index > count) {
808 throw new IndexOutOfBoundsException();
809 }
810 return Character.offsetByCodePointsImpl(value, offset, count,
811 offset+index, codePointOffset) - offset;
812 }
813
814 /**
815 * Copy characters from this string into dst starting at dstBegin.
816 * This method doesn't perform any range checking.
817 */
818 void getChars(char dst[], int dstBegin) {
819 System.arraycopy(value, offset, dst, dstBegin, count);
820 }
821
822 /**
823 * Copies characters from this string into the destination character
824 * array.
825 * <p>
826 * The first character to be copied is at index <code>srcBegin</code>;
827 * the last character to be copied is at index <code>srcEnd-1</code>
828 * (thus the total number of characters to be copied is
829 * <code>srcEnd-srcBegin</code>). The characters are copied into the
830 * subarray of <code>dst</code> starting at index <code>dstBegin</code>
831 * and ending at index:
832 * <p><blockquote><pre>
833 * dstbegin + (srcEnd-srcBegin) - 1
834 * </pre></blockquote>
835 *
836 * @param srcBegin index of the first character in the string
837 * to copy.
838 * @param srcEnd index after the last character in the string
839 * to copy.
840 * @param dst the destination array.
841 * @param dstBegin the start offset in the destination array.
842 * @exception IndexOutOfBoundsException If any of the following
843 * is true:
844 * <ul><li><code>srcBegin</code> is negative.
845 * <li><code>srcBegin</code> is greater than <code>srcEnd</code>
846 * <li><code>srcEnd</code> is greater than the length of this
847 * string
848 * <li><code>dstBegin</code> is negative
849 * <li><code>dstBegin+(srcEnd-srcBegin)</code> is larger than
850 * <code>dst.length</code></ul>
851 */
852 public void getChars(int srcBegin, int srcEnd, char dst[], int dstBegin) {
853 if (srcBegin < 0) {
854 throw new StringIndexOutOfBoundsException(srcBegin);
855 }
856 if (srcEnd > count) {
857 throw new StringIndexOutOfBoundsException(srcEnd);
858 }
859 if (srcBegin > srcEnd) {
860 throw new StringIndexOutOfBoundsException(srcEnd - srcBegin);
861 }
862 System.arraycopy(value, offset + srcBegin, dst, dstBegin,
863 srcEnd - srcBegin);
864 }
865
866 /**
867 * Copies characters from this string into the destination byte array. Each
868 * byte receives the 8 low-order bits of the corresponding character. The
869 * eight high-order bits of each character are not copied and do not
870 * participate in the transfer in any way.
871 *
872 * <p> The first character to be copied is at index {@code srcBegin}; the
873 * last character to be copied is at index {@code srcEnd-1}. The total
874 * number of characters to be copied is {@code srcEnd-srcBegin}. The
875 * characters, converted to bytes, are copied into the subarray of {@code
876 * dst} starting at index {@code dstBegin} and ending at index:
877 *
878 * <blockquote><pre>
879 * dstbegin + (srcEnd-srcBegin) - 1
880 * </pre></blockquote>
881 *
882 * @deprecated This method does not properly convert characters into
883 * bytes. As of JDK 1.1, the preferred way to do this is via the
884 * {@link #getBytes()} method, which uses the platform's default charset.
885 *
886 * @param srcBegin
887 * Index of the first character in the string to copy
888 *
889 * @param srcEnd
890 * Index after the last character in the string to copy
891 *
892 * @param dst
893 * The destination array
894 *
895 * @param dstBegin
896 * The start offset in the destination array
897 *
898 * @throws IndexOutOfBoundsException
899 * If any of the following is true:
900 * <ul>
901 * <li> {@code srcBegin} is negative
902 * <li> {@code srcBegin} is greater than {@code srcEnd}
903 * <li> {@code srcEnd} is greater than the length of this String
904 * <li> {@code dstBegin} is negative
905 * <li> {@code dstBegin+(srcEnd-srcBegin)} is larger than {@code
906 * dst.length}
907 * </ul>
908 */
909 @Deprecated
910 public void getBytes(int srcBegin, int srcEnd, byte dst[], int dstBegin) {
911 if (srcBegin < 0) {
912 throw new StringIndexOutOfBoundsException(srcBegin);
913 }
914 if (srcEnd > count) {
915 throw new StringIndexOutOfBoundsException(srcEnd);
916 }
917 if (srcBegin > srcEnd) {
918 throw new StringIndexOutOfBoundsException(srcEnd - srcBegin);
919 }
920 int j = dstBegin;
921 int n = offset + srcEnd;
922 int i = offset + srcBegin;
923 char[] val = value; /* avoid getfield opcode */
924
925 while (i < n) {
926 dst[j++] = (byte)val[i++];
927 }
928 }
929
930 /**
931 * Encodes this {@code String} into a sequence of bytes using the named
932 * charset, storing the result into a new byte array.
933 *
934 * <p> The behavior of this method when this string cannot be encoded in
935 * the given charset is unspecified. The {@link
936 * java.nio.charset.CharsetEncoder} class should be used when more control
937 * over the encoding process is required.
938 *
939 * @param charsetName
940 * The name of a supported {@linkplain java.nio.charset.Charset
941 * charset}
942 *
943 * @return The resultant byte array
944 *
945 * @throws UnsupportedEncodingException
946 * If the named charset is not supported
947 *
948 * @since JDK1.1
949 */
950 public byte[] getBytes(String charsetName)
951 throws UnsupportedEncodingException
952 {
953 if (charsetName == null) throw new NullPointerException();
954 return StringCoding.encode(charsetName, value, offset, count);
955 }
956
957 /**
958 * Encodes this {@code String} into a sequence of bytes using the given
959 * {@linkplain java.nio.charset.Charset charset}, storing the result into a
960 * new byte array.
961 *
962 * <p> This method always replaces malformed-input and unmappable-character
963 * sequences with this charset's default replacement byte array. The
964 * {@link java.nio.charset.CharsetEncoder} class should be used when more
965 * control over the encoding process is required.
966 *
967 * @param charset
968 * The {@linkplain java.nio.charset.Charset} to be used to encode
969 * the {@code String}
970 *
971 * @return The resultant byte array
972 *
973 * @since 1.6
974 */
975 public byte[] getBytes(Charset charset) {
976 if (charset == null) throw new NullPointerException();
977 return StringCoding.encode(charset, value, offset, count);
978 }
979
980 /**
981 * Encodes this {@code String} into a sequence of bytes using the
982 * platform's default charset, storing the result into a new byte array.
983 *
984 * <p> The behavior of this method when this string cannot be encoded in
985 * the default charset is unspecified. The {@link
986 * java.nio.charset.CharsetEncoder} class should be used when more control
987 * over the encoding process is required.
988 *
989 * @return The resultant byte array
990 *
991 * @since JDK1.1
992 */
993 public byte[] getBytes() {
994 return StringCoding.encode(value, offset, count);
995 }
996
997 /**
998 * Compares this string to the specified object. The result is {@code
999 * true} if and only if the argument is not {@code null} and is a {@code
1000 * String} object that represents the same sequence of characters as this
1001 * object.
1002 *
1003 * @param anObject
1004 * The object to compare this {@code String} against
1005 *
1006 * @return {@code true} if the given object represents a {@code String}
1007 * equivalent to this string, {@code false} otherwise
1008 *
1009 * @see #compareTo(String)
1010 * @see #equalsIgnoreCase(String)
1011 */
1012 public boolean equals(Object anObject) {
1013 if (this == anObject) {
1014 return true;
1015 }
1016 if (anObject instanceof String) {
1017 String anotherString = (String)anObject;
1018 int n = count;
1019 if (n == anotherString.count) {
1020 char v1[] = value;
1021 char v2[] = anotherString.value;
1022 int i = offset;
1023 int j = anotherString.offset;
1024 while (n-- != 0) {
1025 if (v1[i++] != v2[j++])
1026 return false;
1027 }
1028 return true;
1029 }
1030 }
1031 return false;
1032 }
1033
1034 /**
1035 * Compares this string to the specified {@code StringBuffer}. The result
1036 * is {@code true} if and only if this {@code String} represents the same
1037 * sequence of characters as the specified {@code StringBuffer}.
1038 *
1039 * @param sb
1040 * The {@code StringBuffer} to compare this {@code String} against
1041 *
1042 * @return {@code true} if this {@code String} represents the same
1043 * sequence of characters as the specified {@code StringBuffer},
1044 * {@code false} otherwise
1045 *
1046 * @since 1.4
1047 */
1048 public boolean contentEquals(StringBuffer sb) {
1049 synchronized(sb) {
1050 return contentEquals((CharSequence)sb);
1051 }
1052 }
1053
1054 /**
1055 * Compares this string to the specified {@code CharSequence}. The result
1056 * is {@code true} if and only if this {@code String} represents the same
1057 * sequence of char values as the specified sequence.
1058 *
1059 * @param cs
1060 * The sequence to compare this {@code String} against
1061 *
1062 * @return {@code true} if this {@code String} represents the same
1063 * sequence of char values as the specified sequence, {@code
1064 * false} otherwise
1065 *
1066 * @since 1.5
1067 */
1068 public boolean contentEquals(CharSequence cs) {
1069 if (count != cs.length())
1070 return false;
1071 // Argument is a StringBuffer, StringBuilder
1072 if (cs instanceof AbstractStringBuilder) {
1073 char v1[] = value;
1074 char v2[] = ((AbstractStringBuilder)cs).getValue();
1075 int i = offset;
1076 int j = 0;
1077 int n = count;
1078 while (n-- != 0) {
1079 if (v1[i++] != v2[j++])
1080 return false;
1081 }
1082 return true;
1083 }
1084 // Argument is a String
1085 if (cs.equals(this))
1086 return true;
1087 // Argument is a generic CharSequence
1088 char v1[] = value;
1089 int i = offset;
1090 int j = 0;
1091 int n = count;
1092 while (n-- != 0) {
1093 if (v1[i++] != cs.charAt(j++))
1094 return false;
1095 }
1096 return true;
1097 }
1098
1099 /**
1100 * Compares this {@code String} to another {@code String}, ignoring case
1101 * considerations. Two strings are considered equal ignoring case if they
1102 * are of the same length and corresponding characters in the two strings
1103 * are equal ignoring case.
1104 *
1105 * <p> Two characters {@code c1} and {@code c2} are considered the same
1106 * ignoring case if at least one of the following is true:
1107 * <ul>
1108 * <li> The two characters are the same (as compared by the
1109 * {@code ==} operator)
1110 * <li> Applying the method {@link
1111 * java.lang.Character#toUpperCase(char)} to each character
1112 * produces the same result
1113 * <li> Applying the method {@link
1114 * java.lang.Character#toLowerCase(char)} to each character
1115 * produces the same result
1116 * </ul>
1117 *
1118 * @param anotherString
1119 * The {@code String} to compare this {@code String} against
1120 *
1121 * @return {@code true} if the argument is not {@code null} and it
1122 * represents an equivalent {@code String} ignoring case; {@code
1123 * false} otherwise
1124 *
1125 * @see #equals(Object)
1126 */
1127 public boolean equalsIgnoreCase(String anotherString) {
1128 return (this == anotherString) ? true :
1129 (anotherString != null) && (anotherString.count == count) &&
1130 regionMatches(true, 0, anotherString, 0, count);
1131 }
1132
1133 /**
1134 * Compares two strings lexicographically.
1135 * The comparison is based on the Unicode value of each character in
1136 * the strings. The character sequence represented by this
1137 * <code>String</code> object is compared lexicographically to the
1138 * character sequence represented by the argument string. The result is
1139 * a negative integer if this <code>String</code> object
1140 * lexicographically precedes the argument string. The result is a
1141 * positive integer if this <code>String</code> object lexicographically
1142 * follows the argument string. The result is zero if the strings
1143 * are equal; <code>compareTo</code> returns <code>0</code> exactly when
1144 * the {@link #equals(Object)} method would return <code>true</code>.
1145 * <p>
1146 * This is the definition of lexicographic ordering. If two strings are
1147 * different, then either they have different characters at some index
1148 * that is a valid index for both strings, or their lengths are different,
1149 * or both. If they have different characters at one or more index
1150 * positions, let <i>k</i> be the smallest such index; then the string
1151 * whose character at position <i>k</i> has the smaller value, as
1152 * determined by using the < operator, lexicographically precedes the
1153 * other string. In this case, <code>compareTo</code> returns the
1154 * difference of the two character values at position <code>k</code> in
1155 * the two string -- that is, the value:
1156 * <blockquote><pre>
1157 * this.charAt(k)-anotherString.charAt(k)
1158 * </pre></blockquote>
1159 * If there is no index position at which they differ, then the shorter
1160 * string lexicographically precedes the longer string. In this case,
1161 * <code>compareTo</code> returns the difference of the lengths of the
1162 * strings -- that is, the value:
1163 * <blockquote><pre>
1164 * this.length()-anotherString.length()
1165 * </pre></blockquote>
1166 *
1167 * @param anotherString the <code>String</code> to be compared.
1168 * @return the value <code>0</code> if the argument string is equal to
1169 * this string; a value less than <code>0</code> if this string
1170 * is lexicographically less than the string argument; and a
1171 * value greater than <code>0</code> if this string is
1172 * lexicographically greater than the string argument.
1173 */
1174 public int compareTo(String anotherString) {
1175 int len1 = count;
1176 int len2 = anotherString.count;
1177 int n = Math.min(len1, len2);
1178 char v1[] = value;
1179 char v2[] = anotherString.value;
1180 int i = offset;
1181 int j = anotherString.offset;
1182
1183 if (i == j) {
1184 int k = i;
1185 int lim = n + i;
1186 while (k < lim) {
1187 char c1 = v1[k];
1188 char c2 = v2[k];
1189 if (c1 != c2) {
1190 return c1 - c2;
1191 }
1192 k++;
1193 }
1194 } else {
1195 while (n-- != 0) {
1196 char c1 = v1[i++];
1197 char c2 = v2[j++];
1198 if (c1 != c2) {
1199 return c1 - c2;
1200 }
1201 }
1202 }
1203 return len1 - len2;
1204 }
1205
1206 /**
1207 * A Comparator that orders <code>String</code> objects as by
1208 * <code>compareToIgnoreCase</code>. This comparator is serializable.
1209 * <p>
1210 * Note that this Comparator does <em>not</em> take locale into account,
1211 * and will result in an unsatisfactory ordering for certain locales.
1212 * The java.text package provides <em>Collators</em> to allow
1213 * locale-sensitive ordering.
1214 *
1215 * @see java.text.Collator#compare(String, String)
1216 * @since 1.2
1217 */
1218 public static final Comparator<String> CASE_INSENSITIVE_ORDER
1219 = new CaseInsensitiveComparator();
1220 private static class CaseInsensitiveComparator
1221 implements Comparator<String>, java.io.Serializable {
1222 // use serialVersionUID from JDK 1.2.2 for interoperability
1223 private static final long serialVersionUID = 8575799808933029326L;
1224
1225 public int compare(String s1, String s2) {
1226 int n1 = s1.length();
1227 int n2 = s2.length();
1228 int min = Math.min(n1, n2);
1229 for (int i = 0; i < min; i++) {
1230 char c1 = s1.charAt(i);
1231 char c2 = s2.charAt(i);
1232 if (c1 != c2) {
1233 c1 = Character.toUpperCase(c1);
1234 c2 = Character.toUpperCase(c2);
1235 if (c1 != c2) {
1236 c1 = Character.toLowerCase(c1);
1237 c2 = Character.toLowerCase(c2);
1238 if (c1 != c2) {
1239 // No overflow because of numeric promotion
1240 return c1 - c2;
1241 }
1242 }
1243 }
1244 }
1245 return n1 - n2;
1246 }
1247 }
1248
1249 /**
1250 * Compares two strings lexicographically, ignoring case
1251 * differences. This method returns an integer whose sign is that of
1252 * calling <code>compareTo</code> with normalized versions of the strings
1253 * where case differences have been eliminated by calling
1254 * <code>Character.toLowerCase(Character.toUpperCase(character))</code> on
1255 * each character.
1256 * <p>
1257 * Note that this method does <em>not</em> take locale into account,
1258 * and will result in an unsatisfactory ordering for certain locales.
1259 * The java.text package provides <em>collators</em> to allow
1260 * locale-sensitive ordering.
1261 *
1262 * @param str the <code>String</code> to be compared.
1263 * @return a negative integer, zero, or a positive integer as the
1264 * specified String is greater than, equal to, or less
1265 * than this String, ignoring case considerations.
1266 * @see java.text.Collator#compare(String, String)
1267 * @since 1.2
1268 */
1269 public int compareToIgnoreCase(String str) {
1270 return CASE_INSENSITIVE_ORDER.compare(this, str);
1271 }
1272
1273 /**
1274 * Tests if two string regions are equal.
1275 * <p>
1276 * A substring of this <tt>String</tt> object is compared to a substring
1277 * of the argument other. The result is true if these substrings
1278 * represent identical character sequences. The substring of this
1279 * <tt>String</tt> object to be compared begins at index <tt>toffset</tt>
1280 * and has length <tt>len</tt>. The substring of other to be compared
1281 * begins at index <tt>ooffset</tt> and has length <tt>len</tt>. The
1282 * result is <tt>false</tt> if and only if at least one of the following
1283 * is true:
1284 * <ul><li><tt>toffset</tt> is negative.
1285 * <li><tt>ooffset</tt> is negative.
1286 * <li><tt>toffset+len</tt> is greater than the length of this
1287 * <tt>String</tt> object.
1288 * <li><tt>ooffset+len</tt> is greater than the length of the other
1289 * argument.
1290 * <li>There is some nonnegative integer <i>k</i> less than <tt>len</tt>
1291 * such that:
1292 * <tt>this.charAt(toffset+<i>k</i>) != other.charAt(ooffset+<i>k</i>)</tt>
1293 * </ul>
1294 *
1295 * @param toffset the starting offset of the subregion in this string.
1296 * @param other the string argument.
1297 * @param ooffset the starting offset of the subregion in the string
1298 * argument.
1299 * @param len the number of characters to compare.
1300 * @return <code>true</code> if the specified subregion of this string
1301 * exactly matches the specified subregion of the string argument;
1302 * <code>false</code> otherwise.
1303 */
1304 public boolean regionMatches(int toffset, String other, int ooffset,
1305 int len) {
1306 char ta[] = value;
1307 int to = offset + toffset;
1308 char pa[] = other.value;
1309 int po = other.offset + ooffset;
1310 // Note: toffset, ooffset, or len might be near -1>>>1.
1311 if ((ooffset < 0) || (toffset < 0) || (toffset > (long)count - len)
1312 || (ooffset > (long)other.count - len)) {
1313 return false;
1314 }
1315 while (len-- > 0) {
1316 if (ta[to++] != pa[po++]) {
1317 return false;
1318 }
1319 }
1320 return true;
1321 }
1322
1323 /**
1324 * Tests if two string regions are equal.
1325 * <p>
1326 * A substring of this <tt>String</tt> object is compared to a substring
1327 * of the argument <tt>other</tt>. The result is <tt>true</tt> if these
1328 * substrings represent character sequences that are the same, ignoring
1329 * case if and only if <tt>ignoreCase</tt> is true. The substring of
1330 * this <tt>String</tt> object to be compared begins at index
1331 * <tt>toffset</tt> and has length <tt>len</tt>. The substring of
1332 * <tt>other</tt> to be compared begins at index <tt>ooffset</tt> and
1333 * has length <tt>len</tt>. The result is <tt>false</tt> if and only if
1334 * at least one of the following is true:
1335 * <ul><li><tt>toffset</tt> is negative.
1336 * <li><tt>ooffset</tt> is negative.
1337 * <li><tt>toffset+len</tt> is greater than the length of this
1338 * <tt>String</tt> object.
1339 * <li><tt>ooffset+len</tt> is greater than the length of the other
1340 * argument.
1341 * <li><tt>ignoreCase</tt> is <tt>false</tt> and there is some nonnegative
1342 * integer <i>k</i> less than <tt>len</tt> such that:
1343 * <blockquote><pre>
1344 * this.charAt(toffset+k) != other.charAt(ooffset+k)
1345 * </pre></blockquote>
1346 * <li><tt>ignoreCase</tt> is <tt>true</tt> and there is some nonnegative
1347 * integer <i>k</i> less than <tt>len</tt> such that:
1348 * <blockquote><pre>
1349 * Character.toLowerCase(this.charAt(toffset+k)) !=
1350 Character.toLowerCase(other.charAt(ooffset+k))
1351 * </pre></blockquote>
1352 * and:
1353 * <blockquote><pre>
1354 * Character.toUpperCase(this.charAt(toffset+k)) !=
1355 * Character.toUpperCase(other.charAt(ooffset+k))
1356 * </pre></blockquote>
1357 * </ul>
1358 *
1359 * @param ignoreCase if <code>true</code>, ignore case when comparing
1360 * characters.
1361 * @param toffset the starting offset of the subregion in this
1362 * string.
1363 * @param other the string argument.
1364 * @param ooffset the starting offset of the subregion in the string
1365 * argument.
1366 * @param len the number of characters to compare.
1367 * @return <code>true</code> if the specified subregion of this string
1368 * matches the specified subregion of the string argument;
1369 * <code>false</code> otherwise. Whether the matching is exact
1370 * or case insensitive depends on the <code>ignoreCase</code>
1371 * argument.
1372 */
1373 public boolean regionMatches(boolean ignoreCase, int toffset,
1374 String other, int ooffset, int len) {
1375 char ta[] = value;
1376 int to = offset + toffset;
1377 char pa[] = other.value;
1378 int po = other.offset + ooffset;
1379 // Note: toffset, ooffset, or len might be near -1>>>1.
1380 if ((ooffset < 0) || (toffset < 0) || (toffset > (long)count - len) ||
1381 (ooffset > (long)other.count - len)) {
1382 return false;
1383 }
1384 while (len-- > 0) {
1385 char c1 = ta[to++];
1386 char c2 = pa[po++];
1387 if (c1 == c2) {
1388 continue;
1389 }
1390 if (ignoreCase) {
1391 // If characters don't match but case may be ignored,
1392 // try converting both characters to uppercase.
1393 // If the results match, then the comparison scan should
1394 // continue.
1395 char u1 = Character.toUpperCase(c1);
1396 char u2 = Character.toUpperCase(c2);
1397 if (u1 == u2) {
1398 continue;
1399 }
1400 // Unfortunately, conversion to uppercase does not work properly
1401 // for the Georgian alphabet, which has strange rules about case
1402 // conversion. So we need to make one last check before
1403 // exiting.
1404 if (Character.toLowerCase(u1) == Character.toLowerCase(u2)) {
1405 continue;
1406 }
1407 }
1408 return false;
1409 }
1410 return true;
1411 }
1412
1413 /**
1414 * Tests if the substring of this string beginning at the
1415 * specified index starts with the specified prefix.
1416 *
1417 * @param prefix the prefix.
1418 * @param toffset where to begin looking in this string.
1419 * @return <code>true</code> if the character sequence represented by the
1420 * argument is a prefix of the substring of this object starting
1421 * at index <code>toffset</code>; <code>false</code> otherwise.
1422 * The result is <code>false</code> if <code>toffset</code> is
1423 * negative or greater than the length of this
1424 * <code>String</code> object; otherwise the result is the same
1425 * as the result of the expression
1426 * <pre>
1427 * this.substring(toffset).startsWith(prefix)
1428 * </pre>
1429 */
1430 public boolean startsWith(String prefix, int toffset) {
1431 char ta[] = value;
1432 int to = offset + toffset;
1433 char pa[] = prefix.value;
1434 int po = prefix.offset;
1435 int pc = prefix.count;
1436 // Note: toffset might be near -1>>>1.
1437 if ((toffset < 0) || (toffset > count - pc)) {
1438 return false;
1439 }
1440 while (--pc >= 0) {
1441 if (ta[to++] != pa[po++]) {
1442 return false;
1443 }
1444 }
1445 return true;
1446 }
1447
1448 /**
1449 * Tests if this string starts with the specified prefix.
1450 *
1451 * @param prefix the prefix.
1452 * @return <code>true</code> if the character sequence represented by the
1453 * argument is a prefix of the character sequence represented by
1454 * this string; <code>false</code> otherwise.
1455 * Note also that <code>true</code> will be returned if the
1456 * argument is an empty string or is equal to this
1457 * <code>String</code> object as determined by the
1458 * {@link #equals(Object)} method.
1459 * @since 1. 0
1460 */
1461 public boolean startsWith(String prefix) {
1462 return startsWith(prefix, 0);
1463 }
1464
1465 /**
1466 * Tests if this string ends with the specified suffix.
1467 *
1468 * @param suffix the suffix.
1469 * @return <code>true</code> if the character sequence represented by the
1470 * argument is a suffix of the character sequence represented by
1471 * this object; <code>false</code> otherwise. Note that the
1472 * result will be <code>true</code> if the argument is the
1473 * empty string or is equal to this <code>String</code> object
1474 * as determined by the {@link #equals(Object)} method.
1475 */
1476 public boolean endsWith(String suffix) {
1477 return startsWith(suffix, count - suffix.count);
1478 }
1479
1480 /**
1481 * Returns a hash code for this string. The hash code for a
1482 * <code>String</code> object is computed as
1483 * <blockquote><pre>
1484 * s[0]*31^(n-1) + s[1]*31^(n-2) + ... + s[n-1]
1485 * </pre></blockquote>
1486 * using <code>int</code> arithmetic, where <code>s[i]</code> is the
1487 * <i>i</i>th character of the string, <code>n</code> is the length of
1488 * the string, and <code>^</code> indicates exponentiation.
1489 * (The hash value of the empty string is zero.)
1490 *
1491 * @return a hash code value for this object.
1492 */
1493 public int hashCode() {
1494 int h = hash;
1495 if (h == 0 && count > 0) {
1496 int off = offset;
1497 char val[] = value;
1498 int len = count;
1499
1500 for (int i = 0; i < len; i++) {
1501 h = 31*h + val[off++];
1502 }
1503 hash = h;
1504 }
1505 return h;
1506 }
1507
1508 /**
1509 * Returns the index within this string of the first occurrence of
1510 * the specified character. If a character with value
1511 * <code>ch</code> occurs in the character sequence represented by
1512 * this <code>String</code> object, then the index (in Unicode
1513 * code units) of the first such occurrence is returned. For
1514 * values of <code>ch</code> in the range from 0 to 0xFFFF
1515 * (inclusive), this is the smallest value <i>k</i> such that:
1516 * <blockquote><pre>
1517 * this.charAt(<i>k</i>) == ch
1518 * </pre></blockquote>
1519 * is true. For other values of <code>ch</code>, it is the
1520 * smallest value <i>k</i> such that:
1521 * <blockquote><pre>
1522 * this.codePointAt(<i>k</i>) == ch
1523 * </pre></blockquote>
1524 * is true. In either case, if no such character occurs in this
1525 * string, then <code>-1</code> is returned.
1526 *
1527 * @param ch a character (Unicode code point).
1528 * @return the index of the first occurrence of the character in the
1529 * character sequence represented by this object, or
1530 * <code>-1</code> if the character does not occur.
1531 */
1532 public int indexOf(int ch) {
1533 return indexOf(ch, 0);
1534 }
1535
1536 /**
1537 * Returns the index within this string of the first occurrence of the
1538 * specified character, starting the search at the specified index.
1539 * <p>
1540 * If a character with value <code>ch</code> occurs in the
1541 * character sequence represented by this <code>String</code>
1542 * object at an index no smaller than <code>fromIndex</code>, then
1543 * the index of the first such occurrence is returned. For values
1544 * of <code>ch</code> in the range from 0 to 0xFFFF (inclusive),
1545 * this is the smallest value <i>k</i> such that:
1546 * <blockquote><pre>
1547 * (this.charAt(<i>k</i>) == ch) && (<i>k</i> >= fromIndex)
1548 * </pre></blockquote>
1549 * is true. For other values of <code>ch</code>, it is the
1550 * smallest value <i>k</i> such that:
1551 * <blockquote><pre>
1552 * (this.codePointAt(<i>k</i>) == ch) && (<i>k</i> >= fromIndex)
1553 * </pre></blockquote>
1554 * is true. In either case, if no such character occurs in this
1555 * string at or after position <code>fromIndex</code>, then
1556 * <code>-1</code> is returned.
1557 *
1558 * <p>
1559 * There is no restriction on the value of <code>fromIndex</code>. If it
1560 * is negative, it has the same effect as if it were zero: this entire
1561 * string may be searched. If it is greater than the length of this
1562 * string, it has the same effect as if it were equal to the length of
1563 * this string: <code>-1</code> is returned.
1564 *
1565 * <p>All indices are specified in <code>char</code> values
1566 * (Unicode code units).
1567 *
1568 * @param ch a character (Unicode code point).
1569 * @param fromIndex the index to start the search from.
1570 * @return the index of the first occurrence of the character in the
1571 * character sequence represented by this object that is greater
1572 * than or equal to <code>fromIndex</code>, or <code>-1</code>
1573 * if the character does not occur.
1574 */
1575 public int indexOf(int ch, int fromIndex) {
1576 if (fromIndex < 0) {
1577 fromIndex = 0;
1578 } else if (fromIndex >= count) {
1579 // Note: fromIndex might be near -1>>>1.
1580 return -1;
1581 }
1582
1583 if (ch < Character.MIN_SUPPLEMENTARY_CODE_POINT) {
1584 // handle most cases here (ch is a BMP code point or a
1585 // negative value (invalid code point))
1586 final char[] value = this.value;
1587 final int offset = this.offset;
1588 final int max = offset + count;
1589 for (int i = offset + fromIndex; i < max ; i++) {
1590 if (value[i] == ch) {
1591 return i - offset;
1592 }
1593 }
1594 return -1;
1595 } else {
1596 return indexOfSupplementary(ch, fromIndex);
1597 }
1598 }
1599
1600 /**
1601 * Handles (rare) calls of indexOf with a supplementary character.
1602 */
1603 private int indexOfSupplementary(int ch, int fromIndex) {
1604 if (Character.isValidCodePoint(ch)) {
1605 final char[] value = this.value;
1606 final int offset = this.offset;
1607 final char hi = Character.highSurrogate(ch);
1608 final char lo = Character.lowSurrogate(ch);
1609 final int max = offset + count - 1;
1610 for (int i = offset + fromIndex; i < max; i++) {
1611 if (value[i] == hi && value[i+1] == lo) {
1612 return i - offset;
1613 }
1614 }
1615 }
1616 return -1;
1617 }
1618
1619 /**
1620 * Returns the index within this string of the last occurrence of
1621 * the specified character. For values of <code>ch</code> in the
1622 * range from 0 to 0xFFFF (inclusive), the index (in Unicode code
1623 * units) returned is the largest value <i>k</i> such that:
1624 * <blockquote><pre>
1625 * this.charAt(<i>k</i>) == ch
1626 * </pre></blockquote>
1627 * is true. For other values of <code>ch</code>, it is the
1628 * largest value <i>k</i> such that:
1629 * <blockquote><pre>
1630 * this.codePointAt(<i>k</i>) == ch
1631 * </pre></blockquote>
1632 * is true. In either case, if no such character occurs in this
1633 * string, then <code>-1</code> is returned. The
1634 * <code>String</code> is searched backwards starting at the last
1635 * character.
1636 *
1637 * @param ch a character (Unicode code point).
1638 * @return the index of the last occurrence of the character in the
1639 * character sequence represented by this object, or
1640 * <code>-1</code> if the character does not occur.
1641 */
1642 public int lastIndexOf(int ch) {
1643 return lastIndexOf(ch, count - 1);
1644 }
1645
1646 /**
1647 * Returns the index within this string of the last occurrence of
1648 * the specified character, searching backward starting at the
1649 * specified index. For values of <code>ch</code> in the range
1650 * from 0 to 0xFFFF (inclusive), the index returned is the largest
1651 * value <i>k</i> such that:
1652 * <blockquote><pre>
1653 * (this.charAt(<i>k</i>) == ch) && (<i>k</i> <= fromIndex)
1654 * </pre></blockquote>
1655 * is true. For other values of <code>ch</code>, it is the
1656 * largest value <i>k</i> such that:
1657 * <blockquote><pre>
1658 * (this.codePointAt(<i>k</i>) == ch) && (<i>k</i> <= fromIndex)
1659 * </pre></blockquote>
1660 * is true. In either case, if no such character occurs in this
1661 * string at or before position <code>fromIndex</code>, then
1662 * <code>-1</code> is returned.
1663 *
1664 * <p>All indices are specified in <code>char</code> values
1665 * (Unicode code units).
1666 *
1667 * @param ch a character (Unicode code point).
1668 * @param fromIndex the index to start the search from. There is no
1669 * restriction on the value of <code>fromIndex</code>. If it is
1670 * greater than or equal to the length of this string, it has
1671 * the same effect as if it were equal to one less than the
1672 * length of this string: this entire string may be searched.
1673 * If it is negative, it has the same effect as if it were -1:
1674 * -1 is returned.
1675 * @return the index of the last occurrence of the character in the
1676 * character sequence represented by this object that is less
1677 * than or equal to <code>fromIndex</code>, or <code>-1</code>
1678 * if the character does not occur before that point.
1679 */
1680 public int lastIndexOf(int ch, int fromIndex) {
1681 if (ch < Character.MIN_SUPPLEMENTARY_CODE_POINT) {
1682 // handle most cases here (ch is a BMP code point or a
1683 // negative value (invalid code point))
1684 final char[] value = this.value;
1685 final int offset = this.offset;
1686 int i = offset + Math.min(fromIndex, count - 1);
1687 for (; i >= offset ; i--) {
1688 if (value[i] == ch) {
1689 return i - offset;
1690 }
1691 }
1692 return -1;
1693 } else {
1694 return lastIndexOfSupplementary(ch, fromIndex);
1695 }
1696 }
1697
1698 /**
1699 * Handles (rare) calls of lastIndexOf with a supplementary character.
1700 */
1701 private int lastIndexOfSupplementary(int ch, int fromIndex) {
1702 if (Character.isValidCodePoint(ch)) {
1703 final char[] value = this.value;
1704 final int offset = this.offset;
1705 char hi = Character.highSurrogate(ch);
1706 char lo = Character.lowSurrogate(ch);
1707 int i = offset + Math.min(fromIndex, count - 2);
1708 for (; i >= offset; i--) {
1709 if (value[i] == hi && value[i+1] == lo) {
1710 return i - offset;
1711 }
1712 }
1713 }
1714 return -1;
1715 }
1716
1717 /**
1718 * Returns the index within this string of the first occurrence of the
1719 * specified substring.
1720 *
1721 * <p>The returned index is the smallest value <i>k</i> for which:
1722 * <blockquote><pre>
1723 * this.startsWith(str, <i>k</i>)
1724 * </pre></blockquote>
1725 * If no such value of <i>k</i> exists, then {@code -1} is returned.
1726 *
1727 * @param str the substring to search for.
1728 * @return the index of the first occurrence of the specified substring,
1729 * or {@code -1} if there is no such occurrence.
1730 */
1731 public int indexOf(String str) {
1732 return indexOf(str, 0);
1733 }
1734
1735 /**
1736 * Returns the index within this string of the first occurrence of the
1737 * specified substring, starting at the specified index.
1738 *
1739 * <p>The returned index is the smallest value <i>k</i> for which:
1740 * <blockquote><pre>
1741 * <i>k</i> >= fromIndex && this.startsWith(str, <i>k</i>)
1742 * </pre></blockquote>
1743 * If no such value of <i>k</i> exists, then {@code -1} is returned.
1744 *
1745 * @param str the substring to search for.
1746 * @param fromIndex the index from which to start the search.
1747 * @return the index of the first occurrence of the specified substring,
1748 * starting at the specified index,
1749 * or {@code -1} if there is no such occurrence.
1750 */
1751 public int indexOf(String str, int fromIndex) {
1752 return indexOf(value, offset, count,
1753 str.value, str.offset, str.count, fromIndex);
1754 }
1755
1756 /**
1757 * Code shared by String and StringBuffer to do searches. The
1758 * source is the character array being searched, and the target
1759 * is the string being searched for.
1760 *
1761 * @param source the characters being searched.
1762 * @param sourceOffset offset of the source string.
1763 * @param sourceCount count of the source string.
1764 * @param target the characters being searched for.
1765 * @param targetOffset offset of the target string.
1766 * @param targetCount count of the target string.
1767 * @param fromIndex the index to begin searching from.
1768 */
1769 static int indexOf(char[] source, int sourceOffset, int sourceCount,
1770 char[] target, int targetOffset, int targetCount,
1771 int fromIndex) {
1772 if (fromIndex >= sourceCount) {
1773 return (targetCount == 0 ? sourceCount : -1);
1774 }
1775 if (fromIndex < 0) {
1776 fromIndex = 0;
1777 }
1778 if (targetCount == 0) {
1779 return fromIndex;
1780 }
1781
1782 char first = target[targetOffset];
1783 int max = sourceOffset + (sourceCount - targetCount);
1784
1785 for (int i = sourceOffset + fromIndex; i <= max; i++) {
1786 /* Look for first character. */
1787 if (source[i] != first) {
1788 while (++i <= max && source[i] != first);
1789 }
1790
1791 /* Found first character, now look at the rest of v2 */
1792 if (i <= max) {
1793 int j = i + 1;
1794 int end = j + targetCount - 1;
1795 for (int k = targetOffset + 1; j < end && source[j] ==
1796 target[k]; j++, k++);
1797
1798 if (j == end) {
1799 /* Found whole string. */
1800 return i - sourceOffset;
1801 }
1802 }
1803 }
1804 return -1;
1805 }
1806
1807 /**
1808 * Returns the index within this string of the last occurrence of the
1809 * specified substring. The last occurrence of the empty string ""
1810 * is considered to occur at the index value {@code this.length()}.
1811 *
1812 * <p>The returned index is the largest value <i>k</i> for which:
1813 * <blockquote><pre>
1814 * this.startsWith(str, <i>k</i>)
1815 * </pre></blockquote>
1816 * If no such value of <i>k</i> exists, then {@code -1} is returned.
1817 *
1818 * @param str the substring to search for.
1819 * @return the index of the last occurrence of the specified substring,
1820 * or {@code -1} if there is no such occurrence.
1821 */
1822 public int lastIndexOf(String str) {
1823 return lastIndexOf(str, count);
1824 }
1825
1826 /**
1827 * Returns the index within this string of the last occurrence of the
1828 * specified substring, searching backward starting at the specified index.
1829 *
1830 * <p>The returned index is the largest value <i>k</i> for which:
1831 * <blockquote><pre>
1832 * <i>k</i> <= fromIndex && this.startsWith(str, <i>k</i>)
1833 * </pre></blockquote>
1834 * If no such value of <i>k</i> exists, then {@code -1} is returned.
1835 *
1836 * @param str the substring to search for.
1837 * @param fromIndex the index to start the search from.
1838 * @return the index of the last occurrence of the specified substring,
1839 * searching backward from the specified index,
1840 * or {@code -1} if there is no such occurrence.
1841 */
1842 public int lastIndexOf(String str, int fromIndex) {
1843 return lastIndexOf(value, offset, count,
1844 str.value, str.offset, str.count, fromIndex);
1845 }
1846
1847 /**
1848 * Code shared by String and StringBuffer to do searches. The
1849 * source is the character array being searched, and the target
1850 * is the string being searched for.
1851 *
1852 * @param source the characters being searched.
1853 * @param sourceOffset offset of the source string.
1854 * @param sourceCount count of the source string.
1855 * @param target the characters being searched for.
1856 * @param targetOffset offset of the target string.
1857 * @param targetCount count of the target string.
1858 * @param fromIndex the index to begin searching from.
1859 */
1860 static int lastIndexOf(char[] source, int sourceOffset, int sourceCount,
1861 char[] target, int targetOffset, int targetCount,
1862 int fromIndex) {
1863 /*
1864 * Check arguments; return immediately where possible. For
1865 * consistency, don't check for null str.
1866 */
1867 int rightIndex = sourceCount - targetCount;
1868 if (fromIndex < 0) {
1869 return -1;
1870 }
1871 if (fromIndex > rightIndex) {
1872 fromIndex = rightIndex;
1873 }
1874 /* Empty string always matches. */
1875 if (targetCount == 0) {
1876 return fromIndex;
1877 }
1878
1879 int strLastIndex = targetOffset + targetCount - 1;
1880 char strLastChar = target[strLastIndex];
1881 int min = sourceOffset + targetCount - 1;
1882 int i = min + fromIndex;
1883
1884 startSearchForLastChar:
1885 while (true) {
1886 while (i >= min && source[i] != strLastChar) {
1887 i--;
1888 }
1889 if (i < min) {
1890 return -1;
1891 }
1892 int j = i - 1;
1893 int start = j - (targetCount - 1);
1894 int k = strLastIndex - 1;
1895
1896 while (j > start) {
1897 if (source[j--] != target[k--]) {
1898 i--;
1899 continue startSearchForLastChar;
1900 }
1901 }
1902 return start - sourceOffset + 1;
1903 }
1904 }
1905
1906 /**
1907 * Returns a new string that is a substring of this string. The
1908 * substring begins with the character at the specified index and
1909 * extends to the end of this string. <p>
1910 * Examples:
1911 * <blockquote><pre>
1912 * "unhappy".substring(2) returns "happy"
1913 * "Harbison".substring(3) returns "bison"
1914 * "emptiness".substring(9) returns "" (an empty string)
1915 * </pre></blockquote>
1916 *
1917 * @param beginIndex the beginning index, inclusive.
1918 * @return the specified substring.
1919 * @exception IndexOutOfBoundsException if
1920 * <code>beginIndex</code> is negative or larger than the
1921 * length of this <code>String</code> object.
1922 */
1923 public String substring(int beginIndex) {
1924 return substring(beginIndex, count);
1925 }
1926
1927 /**
1928 * Returns a new string that is a substring of this string. The
1929 * substring begins at the specified <code>beginIndex</code> and
1930 * extends to the character at index <code>endIndex - 1</code>.
1931 * Thus the length of the substring is <code>endIndex-beginIndex</code>.
1932 * <p>
1933 * Examples:
1934 * <blockquote><pre>
1935 * "hamburger".substring(4, 8) returns "urge"
1936 * "smiles".substring(1, 5) returns "mile"
1937 * </pre></blockquote>
1938 *
1939 * @param beginIndex the beginning index, inclusive.
1940 * @param endIndex the ending index, exclusive.
1941 * @return the specified substring.
1942 * @exception IndexOutOfBoundsException if the
1943 * <code>beginIndex</code> is negative, or
1944 * <code>endIndex</code> is larger than the length of
1945 * this <code>String</code> object, or
1946 * <code>beginIndex</code> is larger than
1947 * <code>endIndex</code>.
1948 */
1949 public String substring(int beginIndex, int endIndex) {
1950 if (beginIndex < 0) {
1951 throw new StringIndexOutOfBoundsException(beginIndex);
1952 }
1953 if (endIndex > count) {
1954 throw new StringIndexOutOfBoundsException(endIndex);
1955 }
1956 if (beginIndex > endIndex) {
1957 throw new StringIndexOutOfBoundsException(endIndex - beginIndex);
1958 }
1959 return ((beginIndex == 0) && (endIndex == count)) ? this :
1960 new String(offset + beginIndex, endIndex - beginIndex, value);
1961 }
1962
1963 /**
1964 * Returns a new character sequence that is a subsequence of this sequence.
1965 *
1966 * <p> An invocation of this method of the form
1967 *
1968 * <blockquote><pre>
1969 * str.subSequence(begin, end)</pre></blockquote>
1970 *
1971 * behaves in exactly the same way as the invocation
1972 *
1973 * <blockquote><pre>
1974 * str.substring(begin, end)</pre></blockquote>
1975 *
1976 * This method is defined so that the <tt>String</tt> class can implement
1977 * the {@link CharSequence} interface. </p>
1978 *
1979 * @param beginIndex the begin index, inclusive.
1980 * @param endIndex the end index, exclusive.
1981 * @return the specified subsequence.
1982 *
1983 * @throws IndexOutOfBoundsException
1984 * if <tt>beginIndex</tt> or <tt>endIndex</tt> are negative,
1985 * if <tt>endIndex</tt> is greater than <tt>length()</tt>,
1986 * or if <tt>beginIndex</tt> is greater than <tt>startIndex</tt>
1987 *
1988 * @since 1.4
1989 * @spec JSR-51
1990 */
1991 public CharSequence subSequence(int beginIndex, int endIndex) {
1992 return this.substring(beginIndex, endIndex);
1993 }
1994
1995 /**
1996 * Concatenates the specified string to the end of this string.
1997 * <p>
1998 * If the length of the argument string is <code>0</code>, then this
1999 * <code>String</code> object is returned. Otherwise, a new
2000 * <code>String</code> object is created, representing a character
2001 * sequence that is the concatenation of the character sequence
2002 * represented by this <code>String</code> object and the character
2003 * sequence represented by the argument string.<p>
2004 * Examples:
2005 * <blockquote><pre>
2006 * "cares".concat("s") returns "caress"
2007 * "to".concat("get").concat("her") returns "together"
2008 * </pre></blockquote>
2009 *
2010 * @param str the <code>String</code> that is concatenated to the end
2011 * of this <code>String</code>.
2012 * @return a string that represents the concatenation of this object's
2013 * characters followed by the string argument's characters.
2014 */
2015 public String concat(String str) {
2016 int otherLen = str.length();
2017 if (otherLen == 0) {
2018 return this;
2019 }
2020 char buf[] = new char[count + otherLen];
2021 getChars(0, count, buf, 0);
2022 str.getChars(0, otherLen, buf, count);
2023 return new String(0, count + otherLen, buf);
2024 }
2025
2026 /**
2027 * Returns a new string resulting from replacing all occurrences of
2028 * <code>oldChar</code> in this string with <code>newChar</code>.
2029 * <p>
2030 * If the character <code>oldChar</code> does not occur in the
2031 * character sequence represented by this <code>String</code> object,
2032 * then a reference to this <code>String</code> object is returned.
2033 * Otherwise, a new <code>String</code> object is created that
2034 * represents a character sequence identical to the character sequence
2035 * represented by this <code>String</code> object, except that every
2036 * occurrence of <code>oldChar</code> is replaced by an occurrence
2037 * of <code>newChar</code>.
2038 * <p>
2039 * Examples:
2040 * <blockquote><pre>
2041 * "mesquite in your cellar".replace('e', 'o')
2042 * returns "mosquito in your collar"
2043 * "the war of baronets".replace('r', 'y')
2044 * returns "the way of bayonets"
2045 * "sparring with a purple porpoise".replace('p', 't')
2046 * returns "starring with a turtle tortoise"
2047 * "JonL".replace('q', 'x') returns "JonL" (no change)
2048 * </pre></blockquote>
2049 *
2050 * @param oldChar the old character.
2051 * @param newChar the new character.
2052 * @return a string derived from this string by replacing every
2053 * occurrence of <code>oldChar</code> with <code>newChar</code>.
2054 */
2055 public String replace(char oldChar, char newChar) {
2056 if (oldChar != newChar) {
2057 int len = count;
2058 int i = -1;
2059 char[] val = value; /* avoid getfield opcode */
2060 int off = offset; /* avoid getfield opcode */
2061
2062 while (++i < len) {
2063 if (val[off + i] == oldChar) {
2064 break;
2065 }
2066 }
2067 if (i < len) {
2068 char buf[] = new char[len];
2069 for (int j = 0 ; j < i ; j++) {
2070 buf[j] = val[off+j];
2071 }
2072 while (i < len) {
2073 char c = val[off + i];
2074 buf[i] = (c == oldChar) ? newChar : c;
2075 i++;
2076 }
2077 return new String(0, len, buf);
2078 }
2079 }
2080 return this;
2081 }
2082
2083 /**
2084 * Tells whether or not this string matches the given <a
2085 * href="../util/regex/Pattern.html#sum">regular expression</a>.
2086 *
2087 * <p> An invocation of this method of the form
2088 * <i>str</i><tt>.matches(</tt><i>regex</i><tt>)</tt> yields exactly the
2089 * same result as the expression
2090 *
2091 * <blockquote><tt> {@link java.util.regex.Pattern}.{@link
2092 * java.util.regex.Pattern#matches(String,CharSequence)
2093 * matches}(</tt><i>regex</i><tt>,</tt> <i>str</i><tt>)</tt></blockquote>
2094 *
2095 * @param regex
2096 * the regular expression to which this string is to be matched
2097 *
2098 * @return <tt>true</tt> if, and only if, this string matches the
2099 * given regular expression
2100 *
2101 * @throws PatternSyntaxException
2102 * if the regular expression's syntax is invalid
2103 *
2104 * @see java.util.regex.Pattern
2105 *
2106 * @since 1.4
2107 * @spec JSR-51
2108 */
2109 public boolean matches(String regex) {
2110 return Pattern.matches(regex, this);
2111 }
2112
2113 /**
2114 * Returns true if and only if this string contains the specified
2115 * sequence of char values.
2116 *
2117 * @param s the sequence to search for
2118 * @return true if this string contains <code>s</code>, false otherwise
2119 * @throws NullPointerException if <code>s</code> is <code>null</code>
2120 * @since 1.5
2121 */
2122 public boolean contains(CharSequence s) {
2123 return indexOf(s.toString()) > -1;
2124 }
2125
2126 /**
2127 * Replaces the first substring of this string that matches the given <a
2128 * href="../util/regex/Pattern.html#sum">regular expression</a> with the
2129 * given replacement.
2130 *
2131 * <p> An invocation of this method of the form
2132 * <i>str</i><tt>.replaceFirst(</tt><i>regex</i><tt>,</tt> <i>repl</i><tt>)</tt>
2133 * yields exactly the same result as the expression
2134 *
2135 * <blockquote><tt>
2136 * {@link java.util.regex.Pattern}.{@link java.util.regex.Pattern#compile
2137 * compile}(</tt><i>regex</i><tt>).{@link
2138 * java.util.regex.Pattern#matcher(java.lang.CharSequence)
2139 * matcher}(</tt><i>str</i><tt>).{@link java.util.regex.Matcher#replaceFirst
2140 * replaceFirst}(</tt><i>repl</i><tt>)</tt></blockquote>
2141 *
2142 *<p>
2143 * Note that backslashes (<tt>\</tt>) and dollar signs (<tt>$</tt>) in the
2144 * replacement string may cause the results to be different than if it were
2145 * being treated as a literal replacement string; see
2146 * {@link java.util.regex.Matcher#replaceFirst}.
2147 * Use {@link java.util.regex.Matcher#quoteReplacement} to suppress the special
2148 * meaning of these characters, if desired.
2149 *
2150 * @param regex
2151 * the regular expression to which this string is to be matched
2152 * @param replacement
2153 * the string to be substituted for the first match
2154 *
2155 * @return The resulting <tt>String</tt>
2156 *
2157 * @throws PatternSyntaxException
2158 * if the regular expression's syntax is invalid
2159 *
2160 * @see java.util.regex.Pattern
2161 *
2162 * @since 1.4
2163 * @spec JSR-51
2164 */
2165 public String replaceFirst(String regex, String replacement) {
2166 return Pattern.compile(regex).matcher(this).replaceFirst(replacement);
2167 }
2168
2169 /**
2170 * Replaces each substring of this string that matches the given <a
2171 * href="../util/regex/Pattern.html#sum">regular expression</a> with the
2172 * given replacement.
2173 *
2174 * <p> An invocation of this method of the form
2175 * <i>str</i><tt>.replaceAll(</tt><i>regex</i><tt>,</tt> <i>repl</i><tt>)</tt>
2176 * yields exactly the same result as the expression
2177 *
2178 * <blockquote><tt>
2179 * {@link java.util.regex.Pattern}.{@link java.util.regex.Pattern#compile
2180 * compile}(</tt><i>regex</i><tt>).{@link
2181 * java.util.regex.Pattern#matcher(java.lang.CharSequence)
2182 * matcher}(</tt><i>str</i><tt>).{@link java.util.regex.Matcher#replaceAll
2183 * replaceAll}(</tt><i>repl</i><tt>)</tt></blockquote>
2184 *
2185 *<p>
2186 * Note that backslashes (<tt>\</tt>) and dollar signs (<tt>$</tt>) 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 <tt>String</tt>
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</code> or
2223 * <code>replacement</code> is <code>null</code>.
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 <tt>limit</tt> 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 <tt>"boo:and:foo"</tt>, 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><tt>{ "boo", "and:foo" }</tt></td></tr>
2265 * <tr><td align=center>:</td>
2266 * <td align=center>5</td>
2267 * <td><tt>{ "boo", "and", "foo" }</tt></td></tr>
2268 * <tr><td align=center>:</td>
2269 * <td align=center>-2</td>
2270 * <td><tt>{ "boo", "and", "foo" }</tt></td></tr>
2271 * <tr><td align=center>o</td>
2272 * <td align=center>5</td>
2273 * <td><tt>{ "b", "", ":and:f", "", "" }</tt></td></tr>
2274 * <tr><td align=center>o</td>
2275 * <td align=center>-2</td>
2276 * <td><tt>{ "b", "", ":and:f", "", "" }</tt></td></tr>
2277 * <tr><td align=center>o</td>
2278 * <td align=center>0</td>
2279 * <td><tt>{ "b", "", ":and:f" }</tt></td></tr>
2280 * </table></blockquote>
2281 *
2282 * <p> An invocation of this method of the form
2283 * <i>str.</i><tt>split(</tt><i>regex</i><tt>,</tt> <i>n</i><tt>)</tt>
2284 * yields the same result as the expression
2285 *
2286 * <blockquote>
2287 * {@link java.util.regex.Pattern}.{@link java.util.regex.Pattern#compile
2288 * compile}<tt>(</tt><i>regex</i><tt>)</tt>.{@link
2289 * java.util.regex.Pattern#split(java.lang.CharSequence,int)
2290 * split}<tt>(</tt><i>str</i><tt>,</tt> <i>n</i><tt>)</tt>
2291 * </blockquote>
2292 *
2293 *
2294 * @param regex
2295 * the delimiting regular expression
2296 *
2297 * @param limit
2298 * the result threshold, as described above
2299 *
2300 * @return the array of strings computed by splitting this string
2301 * around matches of the given regular expression
2302 *
2303 * @throws PatternSyntaxException
2304 * if the regular expression's syntax is invalid
2305 *
2306 * @see java.util.regex.Pattern
2307 *
2308 * @since 1.4
2309 * @spec JSR-51
2310 */
2311 public String[] split(String regex, int limit) {
2312 /* fastpath if the regex is a
2313 (1)one-char String and this character is not one of the
2314 RegEx's meta characters ".$|()[{^?*+\\", or
2315 (2)two-char String and the first char is the backslash and
2316 the second is not the ascii digit or ascii letter.
2317 */
2318 char ch = 0;
2319 if (((regex.count == 1 &&
2320 ".$|()[{^?*+\\".indexOf(ch = regex.charAt(0)) == -1) ||
2321 (regex.length() == 2 &&
2322 regex.charAt(0) == '\\' &&
2323 (((ch = regex.charAt(1))-'0')|('9'-ch)) < 0 &&
2324 ((ch-'a')|('z'-ch)) < 0 &&
2325 ((ch-'A')|('Z'-ch)) < 0)) &&
2326 (ch < Character.MIN_HIGH_SURROGATE ||
2327 ch > Character.MAX_LOW_SURROGATE))
2328 {
2329 int off = 0;
2330 int next = 0;
2331 boolean limited = limit > 0;
2332 ArrayList<String> list = new ArrayList<>();
2333 while ((next = indexOf(ch, off)) != -1) {
2334 if (!limited || list.size() < limit - 1) {
2335 list.add(substring(off, next));
2336 off = next + 1;
2337 } else { // last one
2338 //assert (list.size() == limit - 1);
2339 list.add(substring(off, count));
2340 off = count;
2341 break;
2342 }
2343 }
2344 // If no match was found, return this
2345 if (off == 0)
2346 return new String[] { this };
2347
2348 // Add remaining segment
2349 if (!limited || list.size() < limit)
2350 list.add(substring(off, count));
2351
2352 // Construct result
2353 int resultSize = list.size();
2354 if (limit == 0)
2355 while (resultSize > 0 && list.get(resultSize-1).length() == 0)
2356 resultSize--;
2357 String[] result = new String[resultSize];
2358 return list.subList(0, resultSize).toArray(result);
2359 }
2360 return Pattern.compile(regex).split(this, limit);
2361 }
2362
2363 /**
2364 * Splits this string around matches of the given <a
2365 * href="../util/regex/Pattern.html#sum">regular expression</a>.
2366 *
2367 * <p> This method works as if by invoking the two-argument {@link
2368 * #split(String, int) split} method with the given expression and a limit
2369 * argument of zero. Trailing empty strings are therefore not included in
2370 * the resulting array.
2371 *
2372 * <p> The string <tt>"boo:and:foo"</tt>, for example, yields the following
2373 * results with these expressions:
2374 *
2375 * <blockquote><table cellpadding=1 cellspacing=0 summary="Split examples showing regex and result">
2376 * <tr>
2377 * <th>Regex</th>
2378 * <th>Result</th>
2379 * </tr>
2380 * <tr><td align=center>:</td>
2381 * <td><tt>{ "boo", "and", "foo" }</tt></td></tr>
2382 * <tr><td align=center>o</td>
2383 * <td><tt>{ "b", "", ":and:f" }</tt></td></tr>
2384 * </table></blockquote>
2385 *
2386 *
2387 * @param regex
2388 * the delimiting regular expression
2389 *
2390 * @return the array of strings computed by splitting this string
2391 * around matches of the given regular expression
2392 *
2393 * @throws PatternSyntaxException
2394 * if the regular expression's syntax is invalid
2395 *
2396 * @see java.util.regex.Pattern
2397 *
2398 * @since 1.4
2399 * @spec JSR-51
2400 */
2401 public String[] split(String regex) {
2402 return split(regex, 0);
2403 }
2404
2405 /**
2406 * Converts all of the characters in this <code>String</code> to lower
2407 * case using the rules of the given <code>Locale</code>. Case mapping is based
2408 * on the Unicode Standard version specified by the {@link java.lang.Character Character}
2409 * class. Since case mappings are not always 1:1 char mappings, the resulting
2410 * <code>String</code> may be a different length than the original <code>String</code>.
2411 * <p>
2412 * Examples of lowercase mappings are in the following table:
2413 * <table border="1" summary="Lowercase mapping examples showing language code of locale, upper case, lower case, and description">
2414 * <tr>
2415 * <th>Language Code of Locale</th>
2416 * <th>Upper Case</th>
2417 * <th>Lower Case</th>
2418 * <th>Description</th>
2419 * </tr>
2420 * <tr>
2421 * <td>tr (Turkish)</td>
2422 * <td>\u0130</td>
2423 * <td>\u0069</td>
2424 * <td>capital letter I with dot above -> small letter i</td>
2425 * </tr>
2426 * <tr>
2427 * <td>tr (Turkish)</td>
2428 * <td>\u0049</td>
2429 * <td>\u0131</td>
2430 * <td>capital letter I -> small letter dotless i </td>
2431 * </tr>
2432 * <tr>
2433 * <td>(all)</td>
2434 * <td>French Fries</td>
2435 * <td>french fries</td>
2436 * <td>lowercased all chars in String</td>
2437 * </tr>
2438 * <tr>
2439 * <td>(all)</td>
2440 * <td><img src="doc-files/capiota.gif" alt="capiota"><img src="doc-files/capchi.gif" alt="capchi">
2441 * <img src="doc-files/captheta.gif" alt="captheta"><img src="doc-files/capupsil.gif" alt="capupsil">
2442 * <img src="doc-files/capsigma.gif" alt="capsigma"></td>
2443 * <td><img src="doc-files/iota.gif" alt="iota"><img src="doc-files/chi.gif" alt="chi">
2444 * <img src="doc-files/theta.gif" alt="theta"><img src="doc-files/upsilon.gif" alt="upsilon">
2445 * <img src="doc-files/sigma1.gif" alt="sigma"></td>
2446 * <td>lowercased all chars in String</td>
2447 * </tr>
2448 * </table>
2449 *
2450 * @param locale use the case transformation rules for this locale
2451 * @return the <code>String</code>, converted to lowercase.
2452 * @see java.lang.String#toLowerCase()
2453 * @see java.lang.String#toUpperCase()
2454 * @see java.lang.String#toUpperCase(Locale)
2455 * @since 1.1
2456 */
2457 public String toLowerCase(Locale locale) {
2458 if (locale == null) {
2459 throw new NullPointerException();
2460 }
2461
2462 int firstUpper;
2463
2464 /* Now check if there are any characters that need to be changed. */
2465 scan: {
2466 for (firstUpper = 0 ; firstUpper < count; ) {
2467 char c = value[offset+firstUpper];
2468 if ((c >= Character.MIN_HIGH_SURROGATE) &&
2469 (c <= Character.MAX_HIGH_SURROGATE)) {
2470 int supplChar = codePointAt(firstUpper);
2471 if (supplChar != Character.toLowerCase(supplChar)) {
2472 break scan;
2473 }
2474 firstUpper += Character.charCount(supplChar);
2475 } else {
2476 if (c != Character.toLowerCase(c)) {
2477 break scan;
2478 }
2479 firstUpper++;
2480 }
2481 }
2482 return this;
2483 }
2484
2485 char[] result = new char[count];
2486 int resultOffset = 0; /* result may grow, so i+resultOffset
2487 * is the write location in result */
2488
2489 /* Just copy the first few lowerCase characters. */
2490 System.arraycopy(value, offset, result, 0, firstUpper);
2491
2492 String lang = locale.getLanguage();
2493 boolean localeDependent =
2494 (lang == "tr" || lang == "az" || lang == "lt");
2495 char[] lowerCharArray;
2496 int lowerChar;
2497 int srcChar;
2498 int srcCount;
2499 for (int i = firstUpper; i < count; i += srcCount) {
2500 srcChar = (int)value[offset+i];
2501 if ((char)srcChar >= Character.MIN_HIGH_SURROGATE &&
2502 (char)srcChar <= Character.MAX_HIGH_SURROGATE) {
2503 srcChar = codePointAt(i);
2504 srcCount = Character.charCount(srcChar);
2505 } else {
2506 srcCount = 1;
2507 }
2508 if (localeDependent || srcChar == '\u03A3') { // GREEK CAPITAL LETTER SIGMA
2509 lowerChar = ConditionalSpecialCasing.toLowerCaseEx(this, i, locale);
2510 } else if (srcChar == '\u0130') { // LATIN CAPITAL LETTER I DOT
2511 lowerChar = Character.ERROR;
2512 } else {
2513 lowerChar = Character.toLowerCase(srcChar);
2514 }
2515 if ((lowerChar == Character.ERROR) ||
2516 (lowerChar >= Character.MIN_SUPPLEMENTARY_CODE_POINT)) {
2517 if (lowerChar == Character.ERROR) {
2518 if (!localeDependent && srcChar == '\u0130') {
2519 lowerCharArray =
2520 ConditionalSpecialCasing.toLowerCaseCharArray(this, i, Locale.ENGLISH);
2521 } else {
2522 lowerCharArray =
2523 ConditionalSpecialCasing.toLowerCaseCharArray(this, i, locale);
2524 }
2525 } else if (srcCount == 2) {
2526 resultOffset += Character.toChars(lowerChar, result, i + resultOffset) - srcCount;
2527 continue;
2528 } else {
2529 lowerCharArray = Character.toChars(lowerChar);
2530 }
2531
2532 /* Grow result if needed */
2533 int mapLen = lowerCharArray.length;
2534 if (mapLen > srcCount) {
2535 char[] result2 = new char[result.length + mapLen - srcCount];
2536 System.arraycopy(result, 0, result2, 0,
2537 i + resultOffset);
2538 result = result2;
2539 }
2540 for (int x=0; x<mapLen; ++x) {
2541 result[i+resultOffset+x] = lowerCharArray[x];
2542 }
2543 resultOffset += (mapLen - srcCount);
2544 } else {
2545 result[i+resultOffset] = (char)lowerChar;
2546 }
2547 }
2548 return new String(0, count+resultOffset, result);
2549 }
2550
2551 /**
2552 * Converts all of the characters in this <code>String</code> to lower
2553 * case using the rules of the default locale. This is equivalent to calling
2554 * <code>toLowerCase(Locale.getDefault())</code>.
2555 * <p>
2556 * <b>Note:</b> This method is locale sensitive, and may produce unexpected
2557 * results if used for strings that are intended to be interpreted locale
2558 * independently.
2559 * Examples are programming language identifiers, protocol keys, and HTML
2560 * tags.
2561 * For instance, <code>"TITLE".toLowerCase()</code> in a Turkish locale
2562 * returns <code>"t\u005Cu0131tle"</code>, where '\u005Cu0131' is the
2563 * LATIN SMALL LETTER DOTLESS I character.
2564 * To obtain correct results for locale insensitive strings, use
2565 * <code>toLowerCase(Locale.ENGLISH)</code>.
2566 * <p>
2567 * @return the <code>String</code>, converted to lowercase.
2568 * @see java.lang.String#toLowerCase(Locale)
2569 */
2570 public String toLowerCase() {
2571 return toLowerCase(Locale.getDefault());
2572 }
2573
2574 /**
2575 * Converts all of the characters in this <code>String</code> to upper
2576 * case using the rules of the given <code>Locale</code>. Case mapping is based
2577 * on the Unicode Standard version specified by the {@link java.lang.Character Character}
2578 * class. Since case mappings are not always 1:1 char mappings, the resulting
2579 * <code>String</code> may be a different length than the original <code>String</code>.
2580 * <p>
2581 * Examples of locale-sensitive and 1:M case mappings are in the following table.
2582 * <p>
2583 * <table border="1" summary="Examples of locale-sensitive and 1:M case mappings. Shows Language code of locale, lower case, upper case, and description.">
2584 * <tr>
2585 * <th>Language Code of Locale</th>
2586 * <th>Lower Case</th>
2587 * <th>Upper Case</th>
2588 * <th>Description</th>
2589 * </tr>
2590 * <tr>
2591 * <td>tr (Turkish)</td>
2592 * <td>\u0069</td>
2593 * <td>\u0130</td>
2594 * <td>small letter i -> capital letter I with dot above</td>
2595 * </tr>
2596 * <tr>
2597 * <td>tr (Turkish)</td>
2598 * <td>\u0131</td>
2599 * <td>\u0049</td>
2600 * <td>small letter dotless i -> capital letter I</td>
2601 * </tr>
2602 * <tr>
2603 * <td>(all)</td>
2604 * <td>\u00df</td>
2605 * <td>\u0053 \u0053</td>
2606 * <td>small letter sharp s -> two letters: SS</td>
2607 * </tr>
2608 * <tr>
2609 * <td>(all)</td>
2610 * <td>Fahrvergnügen</td>
2611 * <td>FAHRVERGNÜGEN</td>
2612 * <td></td>
2613 * </tr>
2614 * </table>
2615 * @param locale use the case transformation rules for this locale
2616 * @return the <code>String</code>, converted to uppercase.
2617 * @see java.lang.String#toUpperCase()
2618 * @see java.lang.String#toLowerCase()
2619 * @see java.lang.String#toLowerCase(Locale)
2620 * @since 1.1
2621 */
2622 public String toUpperCase(Locale locale) {
2623 if (locale == null) {
2624 throw new NullPointerException();
2625 }
2626
2627 int firstLower;
2628
2629 /* Now check if there are any characters that need to be changed. */
2630 scan: {
2631 for (firstLower = 0 ; firstLower < count; ) {
2632 int c = (int)value[offset+firstLower];
2633 int srcCount;
2634 if ((c >= Character.MIN_HIGH_SURROGATE) &&
2635 (c <= Character.MAX_HIGH_SURROGATE)) {
2636 c = codePointAt(firstLower);
2637 srcCount = Character.charCount(c);
2638 } else {
2639 srcCount = 1;
2640 }
2641 int upperCaseChar = Character.toUpperCaseEx(c);
2642 if ((upperCaseChar == Character.ERROR) ||
2643 (c != upperCaseChar)) {
2644 break scan;
2645 }
2646 firstLower += srcCount;
2647 }
2648 return this;
2649 }
2650
2651 char[] result = new char[count]; /* may grow */
2652 int resultOffset = 0; /* result may grow, so i+resultOffset
2653 * is the write location in result */
2654
2655 /* Just copy the first few upperCase characters. */
2656 System.arraycopy(value, offset, result, 0, firstLower);
2657
2658 String lang = locale.getLanguage();
2659 boolean localeDependent =
2660 (lang == "tr" || lang == "az" || lang == "lt");
2661 char[] upperCharArray;
2662 int upperChar;
2663 int srcChar;
2664 int srcCount;
2665 for (int i = firstLower; i < count; i += srcCount) {
2666 srcChar = (int)value[offset+i];
2667 if ((char)srcChar >= Character.MIN_HIGH_SURROGATE &&
2668 (char)srcChar <= Character.MAX_HIGH_SURROGATE) {
2669 srcChar = codePointAt(i);
2670 srcCount = Character.charCount(srcChar);
2671 } else {
2672 srcCount = 1;
2673 }
2674 if (localeDependent) {
2675 upperChar = ConditionalSpecialCasing.toUpperCaseEx(this, i, locale);
2676 } else {
2677 upperChar = Character.toUpperCaseEx(srcChar);
2678 }
2679 if ((upperChar == Character.ERROR) ||
2680 (upperChar >= Character.MIN_SUPPLEMENTARY_CODE_POINT)) {
2681 if (upperChar == Character.ERROR) {
2682 if (localeDependent) {
2683 upperCharArray =
2684 ConditionalSpecialCasing.toUpperCaseCharArray(this, i, locale);
2685 } else {
2686 upperCharArray = Character.toUpperCaseCharArray(srcChar);
2687 }
2688 } else if (srcCount == 2) {
2689 resultOffset += Character.toChars(upperChar, result, i + resultOffset) - srcCount;
2690 continue;
2691 } else {
2692 upperCharArray = Character.toChars(upperChar);
2693 }
2694
2695 /* Grow result if needed */
2696 int mapLen = upperCharArray.length;
2697 if (mapLen > srcCount) {
2698 char[] result2 = new char[result.length + mapLen - srcCount];
2699 System.arraycopy(result, 0, result2, 0,
2700 i + resultOffset);
2701 result = result2;
2702 }
2703 for (int x=0; x<mapLen; ++x) {
2704 result[i+resultOffset+x] = upperCharArray[x];
2705 }
2706 resultOffset += (mapLen - srcCount);
2707 } else {
2708 result[i+resultOffset] = (char)upperChar;
2709 }
2710 }
2711 return new String(0, count+resultOffset, result);
2712 }
2713
2714 /**
2715 * Converts all of the characters in this <code>String</code> to upper
2716 * case using the rules of the default locale. This method is equivalent to
2717 * <code>toUpperCase(Locale.getDefault())</code>.
2718 * <p>
2719 * <b>Note:</b> This method is locale sensitive, and may produce unexpected
2720 * results if used for strings that are intended to be interpreted locale
2721 * independently.
2722 * Examples are programming language identifiers, protocol keys, and HTML
2723 * tags.
2724 * For instance, <code>"title".toUpperCase()</code> in a Turkish locale
2725 * returns <code>"T\u005Cu0130TLE"</code>, where '\u005Cu0130' is the
2726 * LATIN CAPITAL LETTER I WITH DOT ABOVE character.
2727 * To obtain correct results for locale insensitive strings, use
2728 * <code>toUpperCase(Locale.ENGLISH)</code>.
2729 * <p>
2730 * @return the <code>String</code>, converted to uppercase.
2731 * @see java.lang.String#toUpperCase(Locale)
2732 */
2733 public String toUpperCase() {
2734 return toUpperCase(Locale.getDefault());
2735 }
2736
2737 /**
2738 * Returns a copy of the string, with leading and trailing whitespace
2739 * omitted.
2740 * <p>
2741 * If this <code>String</code> object represents an empty character
2742 * sequence, or the first and last characters of character sequence
2743 * represented by this <code>String</code> object both have codes
2744 * greater than <code>'\u0020'</code> (the space character), then a
2745 * reference to this <code>String</code> object is returned.
2746 * <p>
2747 * Otherwise, if there is no character with a code greater than
2748 * <code>'\u0020'</code> in the string, then a new
2749 * <code>String</code> object representing an empty string is created
2750 * and returned.
2751 * <p>
2752 * Otherwise, let <i>k</i> be the index of the first character in the
2753 * string whose code is greater than <code>'\u0020'</code>, and let
2754 * <i>m</i> be the index of the last character in the string whose code
2755 * is greater than <code>'\u0020'</code>. A new <code>String</code>
2756 * object is created, representing the substring of this string that
2757 * begins with the character at index <i>k</i> and ends with the
2758 * character at index <i>m</i>-that is, the result of
2759 * <code>this.substring(<i>k</i>, <i>m</i>+1)</code>.
2760 * <p>
2761 * This method may be used to trim whitespace (as defined above) from
2762 * the beginning and end of a string.
2763 *
2764 * @return A copy of this string with leading and trailing white
2765 * space removed, or this string if it has no leading or
2766 * trailing white space.
2767 */
2768 public String trim() {
2769 int len = count;
2770 int st = 0;
2771 int off = offset; /* avoid getfield opcode */
2772 char[] val = value; /* avoid getfield opcode */
2773
2774 while ((st < len) && (val[off + st] <= ' ')) {
2775 st++;
2776 }
2777 while ((st < len) && (val[off + len - 1] <= ' ')) {
2778 len--;
2779 }
2780 return ((st > 0) || (len < count)) ? 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 char result[] = new char[count];
2801 getChars(0, count, result, 0);
2802 return result;
2803 }
2804
2805 /**
2806 * Returns a formatted string using the specified format string and
2807 * arguments.
2808 *
2809 * <p> The locale always used is the one returned by {@link
2810 * java.util.Locale#getDefault() Locale.getDefault()}.
2811 *
2812 * @param format
2813 * A <a href="../util/Formatter.html#syntax">format string</a>
2814 *
2815 * @param args
2816 * Arguments referenced by the format specifiers in the format
2817 * string. If there are more arguments than format specifiers, the
2818 * extra arguments are ignored. The number of arguments is
2819 * variable and may be zero. The maximum number of arguments is
2820 * limited by the maximum dimension of a Java array as defined by
2821 * <cite>The Java™ Virtual Machine Specification</cite>.
2822 * The behaviour on a
2823 * <tt>null</tt> argument depends on the <a
2824 * href="../util/Formatter.html#syntax">conversion</a>.
2825 *
2826 * @throws IllegalFormatException
2827 * If a format string contains an illegal syntax, a format
2828 * specifier that is incompatible with the given arguments,
2829 * insufficient arguments given the format string, or other
2830 * illegal conditions. For specification of all possible
2831 * formatting errors, see the <a
2832 * href="../util/Formatter.html#detail">Details</a> section of the
2833 * formatter class specification.
2834 *
2835 * @throws NullPointerException
2836 * If the <tt>format</tt> is <tt>null</tt>
2837 *
2838 * @return A formatted string
2839 *
2840 * @see java.util.Formatter
2841 * @since 1.5
2842 */
2843 public static String format(String format, Object ... args) {
2844 return new Formatter().format(format, args).toString();
2845 }
2846
2847 /**
2848 * Returns a formatted string using the specified locale, format string,
2849 * and arguments.
2850 *
2851 * @param l
2852 * The {@linkplain java.util.Locale locale} to apply during
2853 * formatting. If <tt>l</tt> is <tt>null</tt> then no localization
2854 * is applied.
2855 *
2856 * @param format
2857 * A <a href="../util/Formatter.html#syntax">format string</a>
2858 *
2859 * @param args
2860 * Arguments referenced by the format specifiers in the format
2861 * string. If there are more arguments than format specifiers, the
2862 * extra arguments are ignored. The number of arguments is
2863 * variable and may be zero. The maximum number of arguments is
2864 * limited by the maximum dimension of a Java array as defined by
2865 * <cite>The Java™ Virtual Machine Specification</cite>.
2866 * The behaviour on a
2867 * <tt>null</tt> argument depends on the <a
2868 * href="../util/Formatter.html#syntax">conversion</a>.
2869 *
2870 * @throws IllegalFormatException
2871 * If a format string contains an illegal syntax, a format
2872 * specifier that is incompatible with the given arguments,
2873 * insufficient arguments given the format string, or other
2874 * illegal conditions. For specification of all possible
2875 * formatting errors, see the <a
2876 * href="../util/Formatter.html#detail">Details</a> section of the
2877 * formatter class specification
2878 *
2879 * @throws NullPointerException
2880 * If the <tt>format</tt> is <tt>null</tt>
2881 *
2882 * @return A formatted string
2883 *
2884 * @see java.util.Formatter
2885 * @since 1.5
2886 */
2887 public static String format(Locale l, String format, Object ... args) {
2888 return new Formatter(l).format(format, args).toString();
2889 }
2890
2891 /**
2892 * Returns the string representation of the <code>Object</code> argument.
2893 *
2894 * @param obj an <code>Object</code>.
2895 * @return if the argument is <code>null</code>, then a string equal to
2896 * <code>"null"</code>; otherwise, the value of
2897 * <code>obj.toString()</code> is returned.
2898 * @see java.lang.Object#toString()
2899 */
2900 public static String valueOf(Object obj) {
2901 return (obj == null) ? "null" : obj.toString();
2902 }
2903
2904 /**
2905 * Returns the string representation of the <code>char</code> array
2906 * argument. The contents of the character array are copied; subsequent
2907 * modification of the character array does not affect the newly
2908 * created string.
2909 *
2910 * @param data a <code>char</code> array.
2911 * @return a newly allocated string representing the same sequence of
2912 * characters contained in the character array argument.
2913 */
2914 public static String valueOf(char data[]) {
2915 return new String(data);
2916 }
2917
2918 /**
2919 * Returns the string representation of a specific subarray of the
2920 * <code>char</code> array argument.
2921 * <p>
2922 * The <code>offset</code> argument is the index of the first
2923 * character of the subarray. The <code>count</code> argument
2924 * specifies the length of the subarray. The contents of the subarray
2925 * are copied; subsequent modification of the character array does not
2926 * affect the newly created string.
2927 *
2928 * @param data the character array.
2929 * @param offset the initial offset into the value of the
2930 * <code>String</code>.
2931 * @param count the length of the value of the <code>String</code>.
2932 * @return a string representing the sequence of characters contained
2933 * in the subarray of the character array argument.
2934 * @exception IndexOutOfBoundsException if <code>offset</code> is
2935 * negative, or <code>count</code> is negative, or
2936 * <code>offset+count</code> is larger than
2937 * <code>data.length</code>.
2938 */
2939 public static String valueOf(char data[], int offset, int count) {
2940 return new String(data, offset, count);
2941 }
2942
2943 /**
2944 * Returns a String that represents the character sequence in the
2945 * array specified.
2946 *
2947 * @param data the character array.
2948 * @param offset initial offset of the subarray.
2949 * @param count length of the subarray.
2950 * @return a <code>String</code> that contains the characters of the
2951 * specified subarray of the character array.
2952 */
2953 public static String copyValueOf(char data[], int offset, int count) {
2954 // All public String constructors now copy the data.
2955 return new String(data, offset, count);
2956 }
2957
2958 /**
2959 * Returns a String that represents the character sequence in the
2960 * array specified.
2961 *
2962 * @param data the character array.
2963 * @return a <code>String</code> that contains the characters of the
2964 * character array.
2965 */
2966 public static String copyValueOf(char data[]) {
2967 return copyValueOf(data, 0, data.length);
2968 }
2969
2970 /**
2971 * Returns the string representation of the <code>boolean</code> argument.
2972 *
2973 * @param b a <code>boolean</code>.
2974 * @return if the argument is <code>true</code>, a string equal to
2975 * <code>"true"</code> is returned; otherwise, a string equal to
2976 * <code>"false"</code> is returned.
2977 */
2978 public static String valueOf(boolean b) {
2979 return b ? "true" : "false";
2980 }
2981
2982 /**
2983 * Returns the string representation of the <code>char</code>
2984 * argument.
2985 *
2986 * @param c a <code>char</code>.
2987 * @return a string of length <code>1</code> containing
2988 * as its single character the argument <code>c</code>.
2989 */
2990 public static String valueOf(char c) {
2991 char data[] = {c};
2992 return new String(0, 1, data);
2993 }
2994
2995 /**
2996 * Returns the string representation of the <code>int</code> argument.
2997 * <p>
2998 * The representation is exactly the one returned by the
2999 * <code>Integer.toString</code> method of one argument.
3000 *
3001 * @param i an <code>int</code>.
3002 * @return a string representation of the <code>int</code> argument.
3003 * @see java.lang.Integer#toString(int, int)
3004 */
3005 public static String valueOf(int i) {
3006 return Integer.toString(i);
3007 }
3008
3009 /**
3010 * Returns the string representation of the <code>long</code> argument.
3011 * <p>
3012 * The representation is exactly the one returned by the
3013 * <code>Long.toString</code> method of one argument.
3014 *
3015 * @param l a <code>long</code>.
3016 * @return a string representation of the <code>long</code> argument.
3017 * @see java.lang.Long#toString(long)
3018 */
3019 public static String valueOf(long l) {
3020 return Long.toString(l);
3021 }
3022
3023 /**
3024 * Returns the string representation of the <code>float</code> argument.
3025 * <p>
3026 * The representation is exactly the one returned by the
3027 * <code>Float.toString</code> method of one argument.
3028 *
3029 * @param f a <code>float</code>.
3030 * @return a string representation of the <code>float</code> argument.
3031 * @see java.lang.Float#toString(float)
3032 */
3033 public static String valueOf(float f) {
3034 return Float.toString(f);
3035 }
3036
3037 /**
3038 * Returns the string representation of the <code>double</code> argument.
3039 * <p>
3040 * The representation is exactly the one returned by the
3041 * <code>Double.toString</code> method of one argument.
3042 *
3043 * @param d a <code>double</code>.
3044 * @return a string representation of the <code>double</code> argument.
3045 * @see java.lang.Double#toString(double)
3046 */
3047 public static String valueOf(double d) {
3048 return Double.toString(d);
3049 }
3050
3051 /**
3052 * Returns a canonical representation for the string object.
3053 * <p>
3054 * A pool of strings, initially empty, is maintained privately by the
3055 * class <code>String</code>.
3056 * <p>
3057 * When the intern method is invoked, if the pool already contains a
3058 * string equal to this <code>String</code> object as determined by
3059 * the {@link #equals(Object)} method, then the string from the pool is
3060 * returned. Otherwise, this <code>String</code> object is added to the
3061 * pool and a reference to this <code>String</code> object is returned.
3062 * <p>
3063 * It follows that for any two strings <code>s</code> and <code>t</code>,
3064 * <code>s.intern() == t.intern()</code> is <code>true</code>
3065 * if and only if <code>s.equals(t)</code> is <code>true</code>.
3066 * <p>
3067 * All literal strings and string-valued constant expressions are
3068 * interned. String literals are defined in section 3.10.5 of the
3069 * <cite>The Java™ Language Specification</cite>.
3070 *
3071 * @return a string that has the same contents as this string, but is
3072 * guaranteed to be from a pool of unique strings.
3073 */
3074 public native String intern();
3075
3076 /**
3077 * Seed value used for each alternative hash calculated.
3078 */
3079 private static final int HASHING_SEED;
3080
3081 static {
3082 long nanos = System.nanoTime();
3083 long now = System.currentTimeMillis();
3084 int SEED_MATERIAL[] = {
3085 System.identityHashCode(String.class),
3086 System.identityHashCode(System.class),
3087 System.identityHashCode(Thread.currentThread()),
3088 (int) (nanos >>> 32),
3089 (int) nanos,
3090 (int) (now >>> 32),
3091 (int) now,
3092 (int) (System.nanoTime() >> 2)
3093 };
3094
3095 int h = 0;
3096 for(int each : SEED_MATERIAL) {
3097 h ^= each;
3098 }
3099
3100 // Spread bits to regularize both segment and index locations,
3101 // using variant of single-word Wang/Jenkins hash.
3102 h += (h << 15) ^ 0xffffcd7d;
3103 h ^= (h >>> 10);
3104 h += (h << 3);
3105 h ^= (h >>> 6);
3106 h += (h << 2) + (h << 14);
3107
3108 HASHING_SEED = h ^ (h >>> 16);
3109 }
3110
3111 /**
3112 * Cached value of the alternative hashing algorithm result
3113 */
3114 private transient int hash32 = 0;
3115
3116 /**
3117 * Calculates a 32-bit hash value for this string.
3118 *
3119 * @return a 32-bit hash value for this string.
3120 */
3121 int hash32() {
3122 int h = hash32;
3123 if (0 == h) {
3124 // harmless data race on hash32 here.
3125 h = sun.misc.Hashing.murmur3_32(HASHING_SEED, value, offset, count);
3126
3127 // ensure result is not zero to avoid recalcing
3128 h = (0 != h) ? h : 1;
3129
3130 hash32 = h;
3131 }
3132
3133 return h;
3134 }
3135
3136 }