1 /*
2 * Copyright 1994-2006 Sun Microsystems, Inc. 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. Sun designates this
8 * particular file as subject to the "Classpath" exception as provided
9 * by Sun 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 Sun Microsystems, Inc., 4150 Network Circle, Santa Clara,
22 * CA 95054 USA or visit www.sun.com if you need additional information or
23 * have any questions.
24 */
25
26 package java.lang;
27
28 import java.io.ObjectStreamClass;
29 import java.io.ObjectStreamField;
30 import java.io.UnsupportedEncodingException;
31 import java.nio.charset.Charset;
32 import java.util.ArrayList;
33 import java.util.Arrays;
34 import java.util.Comparator;
35 import java.util.Formatter;
36 import java.util.Locale;
37 import java.util.regex.Matcher;
38 import java.util.regex.Pattern;
39 import java.util.regex.PatternSyntaxException;
40
41
42 /**
43 * The <code>String</code> class represents character strings. All
44 * string literals in Java programs, such as <code>"abc"</code>, are
45 * implemented as instances of this class.
46 * <p>
47 * Strings are constant; their values cannot be changed after they
48 * are created. String buffers support mutable strings.
49 * Because String objects are immutable they can be shared. For example:
50 * <p><blockquote><pre>
51 * String str = "abc";
52 * </pre></blockquote><p>
53 * is equivalent to:
54 * <p><blockquote><pre>
55 * char data[] = {'a', 'b', 'c'};
56 * String str = new String(data);
57 * </pre></blockquote><p>
58 * Here are some more examples of how strings can be used:
59 * <p><blockquote><pre>
60 * System.out.println("abc");
61 * String cde = "cde";
62 * System.out.println("abc" + cde);
63 * String c = "abc".substring(2,3);
64 * String d = cde.substring(1, 2);
65 * </pre></blockquote>
66 * <p>
67 * The class <code>String</code> includes methods for examining
68 * individual characters of the sequence, for comparing strings, for
69 * searching strings, for extracting substrings, and for creating a
70 * copy of a string with all characters translated to uppercase or to
71 * lowercase. Case mapping is based on the Unicode Standard version
72 * specified by the {@link java.lang.Character Character} class.
73 * <p>
74 * The Java language provides special support for the string
75 * concatenation operator ( + ), and for conversion of
76 * other objects to strings. String concatenation is implemented
77 * through the <code>StringBuilder</code>(or <code>StringBuffer</code>)
78 * class and its <code>append</code> method.
79 * String conversions are implemented through the method
80 * <code>toString</code>, defined by <code>Object</code> and
81 * inherited by all classes in Java. For additional information on
82 * string concatenation and conversion, see Gosling, Joy, and Steele,
83 * <i>The Java Language Specification</i>.
84 *
85 * <p> Unless otherwise noted, passing a <tt>null</tt> argument to a constructor
86 * or method in this class will cause a {@link NullPointerException} to be
87 * thrown.
88 *
89 * <p>A <code>String</code> represents a string in the UTF-16 format
90 * in which <em>supplementary characters</em> are represented by <em>surrogate
91 * pairs</em> (see the section <a href="Character.html#unicode">Unicode
92 * Character Representations</a> in the <code>Character</code> class for
93 * more information).
94 * Index values refer to <code>char</code> code units, so a supplementary
95 * character uses two positions in a <code>String</code>.
96 * <p>The <code>String</code> class provides methods for dealing with
97 * Unicode code points (i.e., characters), in addition to those for
98 * dealing with Unicode code units (i.e., <code>char</code> values).
99 *
100 * @author Lee Boynton
101 * @author Arthur van Hoff
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 // Pass 1: Compute precise size of char[]
277 int n = 0;
278 for (int i = offset; i < offset + count; i++) {
279 int c = codePoints[i];
280 if (c >= Character.MIN_CODE_POINT &&
281 c < Character.MIN_SUPPLEMENTARY_CODE_POINT)
282 n += 1;
283 else if (Character.isSupplementaryCodePoint(c))
284 n += 2;
285 else throw new IllegalArgumentException(Integer.toString(c));
286 }
287
288 // Pass 2: Allocate and fill in char[]
289 char[] v = new char[n];
290 for (int i = offset, j = 0; i < offset + count; i++) {
291 int c = codePoints[i];
292 if (c < Character.MIN_SUPPLEMENTARY_CODE_POINT) {
293 v[j++] = (char) c;
294 } else {
295 Character.toSurrogates(c, v, j);
296 j += 2;
297 }
298 }
299
300 this.value = v;
301 this.count = v.length;
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) {
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 int max = offset + count;
1577 char v[] = value;
1578
1579 if (fromIndex < 0) {
1580 fromIndex = 0;
1581 } else if (fromIndex >= count) {
1582 // Note: fromIndex might be near -1>>>1.
1583 return -1;
1584 }
1585
1586 int i = offset + fromIndex;
1587 if (ch < Character.MIN_SUPPLEMENTARY_CODE_POINT) {
1588 // handle most cases here (ch is a BMP code point or a
1589 // negative value (invalid code point))
1590 for (; i < max ; i++) {
1591 if (v[i] == ch) {
1592 return i - offset;
1593 }
1594 }
1595 return -1;
1596 }
1597
1598 if (ch <= Character.MAX_CODE_POINT) {
1599 // handle supplementary characters here
1600 char[] surrogates = Character.toChars(ch);
1601 for (; i < max; i++) {
1602 if (v[i] == surrogates[0]) {
1603 if (i + 1 == max) {
1604 break;
1605 }
1606 if (v[i+1] == surrogates[1]) {
1607 return i - offset;
1608 }
1609 }
1610 }
1611 }
1612 return -1;
1613 }
1614
1615 /**
1616 * Returns the index within this string of the last occurrence of
1617 * the specified character. For values of <code>ch</code> in the
1618 * range from 0 to 0xFFFF (inclusive), the index (in Unicode code
1619 * units) returned is the largest value <i>k</i> such that:
1620 * <blockquote><pre>
1621 * this.charAt(<i>k</i>) == ch
1622 * </pre></blockquote>
1623 * is true. For other values of <code>ch</code>, it is the
1624 * largest value <i>k</i> such that:
1625 * <blockquote><pre>
1626 * this.codePointAt(<i>k</i>) == ch
1627 * </pre></blockquote>
1628 * is true. In either case, if no such character occurs in this
1629 * string, then <code>-1</code> is returned. The
1630 * <code>String</code> is searched backwards starting at the last
1631 * character.
1632 *
1633 * @param ch a character (Unicode code point).
1634 * @return the index of the last occurrence of the character in the
1635 * character sequence represented by this object, or
1636 * <code>-1</code> if the character does not occur.
1637 */
1638 public int lastIndexOf(int ch) {
1639 return lastIndexOf(ch, count - 1);
1640 }
1641
1642 /**
1643 * Returns the index within this string of the last occurrence of
1644 * the specified character, searching backward starting at the
1645 * specified index. For values of <code>ch</code> in the range
1646 * from 0 to 0xFFFF (inclusive), the index returned is the largest
1647 * value <i>k</i> such that:
1648 * <blockquote><pre>
1649 * (this.charAt(<i>k</i>) == ch) && (<i>k</i> <= fromIndex)
1650 * </pre></blockquote>
1651 * is true. For other values of <code>ch</code>, it is the
1652 * largest value <i>k</i> such that:
1653 * <blockquote><pre>
1654 * (this.codePointAt(<i>k</i>) == ch) && (<i>k</i> <= fromIndex)
1655 * </pre></blockquote>
1656 * is true. In either case, if no such character occurs in this
1657 * string at or before position <code>fromIndex</code>, then
1658 * <code>-1</code> is returned.
1659 *
1660 * <p>All indices are specified in <code>char</code> values
1661 * (Unicode code units).
1662 *
1663 * @param ch a character (Unicode code point).
1664 * @param fromIndex the index to start the search from. There is no
1665 * restriction on the value of <code>fromIndex</code>. If it is
1666 * greater than or equal to the length of this string, it has
1667 * the same effect as if it were equal to one less than the
1668 * length of this string: this entire string may be searched.
1669 * If it is negative, it has the same effect as if it were -1:
1670 * -1 is returned.
1671 * @return the index of the last occurrence of the character in the
1672 * character sequence represented by this object that is less
1673 * than or equal to <code>fromIndex</code>, or <code>-1</code>
1674 * if the character does not occur before that point.
1675 */
1676 public int lastIndexOf(int ch, int fromIndex) {
1677 int min = offset;
1678 char v[] = value;
1679
1680 int i = offset + ((fromIndex >= count) ? count - 1 : fromIndex);
1681
1682 if (ch < Character.MIN_SUPPLEMENTARY_CODE_POINT) {
1683 // handle most cases here (ch is a BMP code point or a
1684 // negative value (invalid code point))
1685 for (; i >= min ; i--) {
1686 if (v[i] == ch) {
1687 return i - offset;
1688 }
1689 }
1690 return -1;
1691 }
1692
1693 int max = offset + count;
1694 if (ch <= Character.MAX_CODE_POINT) {
1695 // handle supplementary characters here
1696 char[] surrogates = Character.toChars(ch);
1697 for (; i >= min; i--) {
1698 if (v[i] == surrogates[0]) {
1699 if (i + 1 == max) {
1700 break;
1701 }
1702 if (v[i+1] == surrogates[1]) {
1703 return i - offset;
1704 }
1705 }
1706 }
1707 }
1708 return -1;
1709 }
1710
1711 /**
1712 * Returns the index within this string of the first occurrence of the
1713 * specified substring. The integer returned is the smallest value
1714 * <i>k</i> such that:
1715 * <blockquote><pre>
1716 * this.startsWith(str, <i>k</i>)
1717 * </pre></blockquote>
1718 * is <code>true</code>.
1719 *
1720 * @param str any string.
1721 * @return if the string argument occurs as a substring within this
1722 * object, then the index of the first character of the first
1723 * such substring is returned; if it does not occur as a
1724 * substring, <code>-1</code> is returned.
1725 */
1726 public int indexOf(String str) {
1727 return indexOf(str, 0);
1728 }
1729
1730 /**
1731 * Returns the index within this string of the first occurrence of the
1732 * specified substring, starting at the specified index. The integer
1733 * returned is the smallest value <tt>k</tt> for which:
1734 * <blockquote><pre>
1735 * k >= Math.min(fromIndex, this.length()) && this.startsWith(str, k)
1736 * </pre></blockquote>
1737 * If no such value of <i>k</i> exists, then -1 is returned.
1738 *
1739 * @param str the substring for which to search.
1740 * @param fromIndex the index from which to start the search.
1741 * @return the index within this string of the first occurrence of the
1742 * specified substring, starting at the specified index.
1743 */
1744 public int indexOf(String str, int fromIndex) {
1745 return indexOf(value, offset, count,
1746 str.value, str.offset, str.count, fromIndex);
1747 }
1748
1749 /**
1750 * Code shared by String and StringBuffer to do searches. The
1751 * source is the character array being searched, and the target
1752 * is the string being searched for.
1753 *
1754 * @param source the characters being searched.
1755 * @param sourceOffset offset of the source string.
1756 * @param sourceCount count of the source string.
1757 * @param target the characters being searched for.
1758 * @param targetOffset offset of the target string.
1759 * @param targetCount count of the target string.
1760 * @param fromIndex the index to begin searching from.
1761 */
1762 static int indexOf(char[] source, int sourceOffset, int sourceCount,
1763 char[] target, int targetOffset, int targetCount,
1764 int fromIndex) {
1765 if (fromIndex >= sourceCount) {
1766 return (targetCount == 0 ? sourceCount : -1);
1767 }
1768 if (fromIndex < 0) {
1769 fromIndex = 0;
1770 }
1771 if (targetCount == 0) {
1772 return fromIndex;
1773 }
1774
1775 char first = target[targetOffset];
1776 int max = sourceOffset + (sourceCount - targetCount);
1777
1778 for (int i = sourceOffset + fromIndex; i <= max; i++) {
1779 /* Look for first character. */
1780 if (source[i] != first) {
1781 while (++i <= max && source[i] != first);
1782 }
1783
1784 /* Found first character, now look at the rest of v2 */
1785 if (i <= max) {
1786 int j = i + 1;
1787 int end = j + targetCount - 1;
1788 for (int k = targetOffset + 1; j < end && source[j] ==
1789 target[k]; j++, k++);
1790
1791 if (j == end) {
1792 /* Found whole string. */
1793 return i - sourceOffset;
1794 }
1795 }
1796 }
1797 return -1;
1798 }
1799
1800 /**
1801 * Returns the index within this string of the rightmost occurrence
1802 * of the specified substring. The rightmost empty string "" is
1803 * considered to occur at the index value <code>this.length()</code>.
1804 * The returned index is the largest value <i>k</i> such that
1805 * <blockquote><pre>
1806 * this.startsWith(str, k)
1807 * </pre></blockquote>
1808 * is true.
1809 *
1810 * @param str the substring to search for.
1811 * @return if the string argument occurs one or more times as a substring
1812 * within this object, then the index of the first character of
1813 * the last such substring is returned. If it does not occur as
1814 * a substring, <code>-1</code> is returned.
1815 */
1816 public int lastIndexOf(String str) {
1817 return lastIndexOf(str, count);
1818 }
1819
1820 /**
1821 * Returns the index within this string of the last occurrence of the
1822 * specified substring, searching backward starting at the specified index.
1823 * The integer returned is the largest value <i>k</i> such that:
1824 * <blockquote><pre>
1825 * k <= Math.min(fromIndex, this.length()) && this.startsWith(str, k)
1826 * </pre></blockquote>
1827 * If no such value of <i>k</i> exists, then -1 is returned.
1828 *
1829 * @param str the substring to search for.
1830 * @param fromIndex the index to start the search from.
1831 * @return the index within this string of the last occurrence of the
1832 * specified substring.
1833 */
1834 public int lastIndexOf(String str, int fromIndex) {
1835 return lastIndexOf(value, offset, count,
1836 str.value, str.offset, str.count, fromIndex);
1837 }
1838
1839 /**
1840 * Code shared by String and StringBuffer to do searches. The
1841 * source is the character array being searched, and the target
1842 * is the string being searched for.
1843 *
1844 * @param source the characters being searched.
1845 * @param sourceOffset offset of the source string.
1846 * @param sourceCount count of the source string.
1847 * @param target the characters being searched for.
1848 * @param targetOffset offset of the target string.
1849 * @param targetCount count of the target string.
1850 * @param fromIndex the index to begin searching from.
1851 */
1852 static int lastIndexOf(char[] source, int sourceOffset, int sourceCount,
1853 char[] target, int targetOffset, int targetCount,
1854 int fromIndex) {
1855 /*
1856 * Check arguments; return immediately where possible. For
1857 * consistency, don't check for null str.
1858 */
1859 int rightIndex = sourceCount - targetCount;
1860 if (fromIndex < 0) {
1861 return -1;
1862 }
1863 if (fromIndex > rightIndex) {
1864 fromIndex = rightIndex;
1865 }
1866 /* Empty string always matches. */
1867 if (targetCount == 0) {
1868 return fromIndex;
1869 }
1870
1871 int strLastIndex = targetOffset + targetCount - 1;
1872 char strLastChar = target[strLastIndex];
1873 int min = sourceOffset + targetCount - 1;
1874 int i = min + fromIndex;
1875
1876 startSearchForLastChar:
1877 while (true) {
1878 while (i >= min && source[i] != strLastChar) {
1879 i--;
1880 }
1881 if (i < min) {
1882 return -1;
1883 }
1884 int j = i - 1;
1885 int start = j - (targetCount - 1);
1886 int k = strLastIndex - 1;
1887
1888 while (j > start) {
1889 if (source[j--] != target[k--]) {
1890 i--;
1891 continue startSearchForLastChar;
1892 }
1893 }
1894 return start - sourceOffset + 1;
1895 }
1896 }
1897
1898 /**
1899 * Returns a new string that is a substring of this string. The
1900 * substring begins with the character at the specified index and
1901 * extends to the end of this string. <p>
1902 * Examples:
1903 * <blockquote><pre>
1904 * "unhappy".substring(2) returns "happy"
1905 * "Harbison".substring(3) returns "bison"
1906 * "emptiness".substring(9) returns "" (an empty string)
1907 * </pre></blockquote>
1908 *
1909 * @param beginIndex the beginning index, inclusive.
1910 * @return the specified substring.
1911 * @exception IndexOutOfBoundsException if
1912 * <code>beginIndex</code> is negative or larger than the
1913 * length of this <code>String</code> object.
1914 */
1915 public String substring(int beginIndex) {
1916 return substring(beginIndex, count);
1917 }
1918
1919 /**
1920 * Returns a new string that is a substring of this string. The
1921 * substring begins at the specified <code>beginIndex</code> and
1922 * extends to the character at index <code>endIndex - 1</code>.
1923 * Thus the length of the substring is <code>endIndex-beginIndex</code>.
1924 * <p>
1925 * Examples:
1926 * <blockquote><pre>
1927 * "hamburger".substring(4, 8) returns "urge"
1928 * "smiles".substring(1, 5) returns "mile"
1929 * </pre></blockquote>
1930 *
1931 * @param beginIndex the beginning index, inclusive.
1932 * @param endIndex the ending index, exclusive.
1933 * @return the specified substring.
1934 * @exception IndexOutOfBoundsException if the
1935 * <code>beginIndex</code> is negative, or
1936 * <code>endIndex</code> is larger than the length of
1937 * this <code>String</code> object, or
1938 * <code>beginIndex</code> is larger than
1939 * <code>endIndex</code>.
1940 */
1941 public String substring(int beginIndex, int endIndex) {
1942 if (beginIndex < 0) {
1943 throw new StringIndexOutOfBoundsException(beginIndex);
1944 }
1945 if (endIndex > count) {
1946 throw new StringIndexOutOfBoundsException(endIndex);
1947 }
1948 if (beginIndex > endIndex) {
1949 throw new StringIndexOutOfBoundsException(endIndex - beginIndex);
1950 }
1951 return ((beginIndex == 0) && (endIndex == count)) ? this :
1952 new String(offset + beginIndex, endIndex - beginIndex, value);
1953 }
1954
1955 /**
1956 * Returns a new character sequence that is a subsequence of this sequence.
1957 *
1958 * <p> An invocation of this method of the form
1959 *
1960 * <blockquote><pre>
1961 * str.subSequence(begin, end)</pre></blockquote>
1962 *
1963 * behaves in exactly the same way as the invocation
1964 *
1965 * <blockquote><pre>
1966 * str.substring(begin, end)</pre></blockquote>
1967 *
1968 * This method is defined so that the <tt>String</tt> class can implement
1969 * the {@link CharSequence} interface. </p>
1970 *
1971 * @param beginIndex the begin index, inclusive.
1972 * @param endIndex the end index, exclusive.
1973 * @return the specified subsequence.
1974 *
1975 * @throws IndexOutOfBoundsException
1976 * if <tt>beginIndex</tt> or <tt>endIndex</tt> are negative,
1977 * if <tt>endIndex</tt> is greater than <tt>length()</tt>,
1978 * or if <tt>beginIndex</tt> is greater than <tt>startIndex</tt>
1979 *
1980 * @since 1.4
1981 * @spec JSR-51
1982 */
1983 public CharSequence subSequence(int beginIndex, int endIndex) {
1984 return this.substring(beginIndex, endIndex);
1985 }
1986
1987 /**
1988 * Concatenates the specified string to the end of this string.
1989 * <p>
1990 * If the length of the argument string is <code>0</code>, then this
1991 * <code>String</code> object is returned. Otherwise, a new
1992 * <code>String</code> object is created, representing a character
1993 * sequence that is the concatenation of the character sequence
1994 * represented by this <code>String</code> object and the character
1995 * sequence represented by the argument string.<p>
1996 * Examples:
1997 * <blockquote><pre>
1998 * "cares".concat("s") returns "caress"
1999 * "to".concat("get").concat("her") returns "together"
2000 * </pre></blockquote>
2001 *
2002 * @param str the <code>String</code> that is concatenated to the end
2003 * of this <code>String</code>.
2004 * @return a string that represents the concatenation of this object's
2005 * characters followed by the string argument's characters.
2006 */
2007 public String concat(String str) {
2008 int otherLen = str.length();
2009 if (otherLen == 0) {
2010 return this;
2011 }
2012 char buf[] = new char[count + otherLen];
2013 getChars(0, count, buf, 0);
2014 str.getChars(0, otherLen, buf, count);
2015 return new String(0, count + otherLen, buf);
2016 }
2017
2018 /**
2019 * Returns a new string resulting from replacing all occurrences of
2020 * <code>oldChar</code> in this string with <code>newChar</code>.
2021 * <p>
2022 * If the character <code>oldChar</code> does not occur in the
2023 * character sequence represented by this <code>String</code> object,
2024 * then a reference to this <code>String</code> object is returned.
2025 * Otherwise, a new <code>String</code> object is created that
2026 * represents a character sequence identical to the character sequence
2027 * represented by this <code>String</code> object, except that every
2028 * occurrence of <code>oldChar</code> is replaced by an occurrence
2029 * of <code>newChar</code>.
2030 * <p>
2031 * Examples:
2032 * <blockquote><pre>
2033 * "mesquite in your cellar".replace('e', 'o')
2034 * returns "mosquito in your collar"
2035 * "the war of baronets".replace('r', 'y')
2036 * returns "the way of bayonets"
2037 * "sparring with a purple porpoise".replace('p', 't')
2038 * returns "starring with a turtle tortoise"
2039 * "JonL".replace('q', 'x') returns "JonL" (no change)
2040 * </pre></blockquote>
2041 *
2042 * @param oldChar the old character.
2043 * @param newChar the new character.
2044 * @return a string derived from this string by replacing every
2045 * occurrence of <code>oldChar</code> with <code>newChar</code>.
2046 */
2047 public String replace(char oldChar, char newChar) {
2048 if (oldChar != newChar) {
2049 int len = count;
2050 int i = -1;
2051 char[] val = value; /* avoid getfield opcode */
2052 int off = offset; /* avoid getfield opcode */
2053
2054 while (++i < len) {
2055 if (val[off + i] == oldChar) {
2056 break;
2057 }
2058 }
2059 if (i < len) {
2060 char buf[] = new char[len];
2061 for (int j = 0 ; j < i ; j++) {
2062 buf[j] = val[off+j];
2063 }
2064 while (i < len) {
2065 char c = val[off + i];
2066 buf[i] = (c == oldChar) ? newChar : c;
2067 i++;
2068 }
2069 return new String(0, len, buf);
2070 }
2071 }
2072 return this;
2073 }
2074
2075 /**
2076 * Tells whether or not this string matches the given <a
2077 * href="../util/regex/Pattern.html#sum">regular expression</a>.
2078 *
2079 * <p> An invocation of this method of the form
2080 * <i>str</i><tt>.matches(</tt><i>regex</i><tt>)</tt> yields exactly the
2081 * same result as the expression
2082 *
2083 * <blockquote><tt> {@link java.util.regex.Pattern}.{@link
2084 * java.util.regex.Pattern#matches(String,CharSequence)
2085 * matches}(</tt><i>regex</i><tt>,</tt> <i>str</i><tt>)</tt></blockquote>
2086 *
2087 * @param regex
2088 * the regular expression to which this string is to be matched
2089 *
2090 * @return <tt>true</tt> if, and only if, this string matches the
2091 * given regular expression
2092 *
2093 * @throws PatternSyntaxException
2094 * if the regular expression's syntax is invalid
2095 *
2096 * @see java.util.regex.Pattern
2097 *
2098 * @since 1.4
2099 * @spec JSR-51
2100 */
2101 public boolean matches(String regex) {
2102 return Pattern.matches(regex, this);
2103 }
2104
2105 /**
2106 * Returns true if and only if this string contains the specified
2107 * sequence of char values.
2108 *
2109 * @param s the sequence to search for
2110 * @return true if this string contains <code>s</code>, false otherwise
2111 * @throws NullPointerException if <code>s</code> is <code>null</code>
2112 * @since 1.5
2113 */
2114 public boolean contains(CharSequence s) {
2115 return indexOf(s.toString()) > -1;
2116 }
2117
2118 /**
2119 * Replaces the first substring of this string that matches the given <a
2120 * href="../util/regex/Pattern.html#sum">regular expression</a> with the
2121 * given replacement.
2122 *
2123 * <p> An invocation of this method of the form
2124 * <i>str</i><tt>.replaceFirst(</tt><i>regex</i><tt>,</tt> <i>repl</i><tt>)</tt>
2125 * yields exactly the same result as the expression
2126 *
2127 * <blockquote><tt>
2128 * {@link java.util.regex.Pattern}.{@link java.util.regex.Pattern#compile
2129 * compile}(</tt><i>regex</i><tt>).{@link
2130 * java.util.regex.Pattern#matcher(java.lang.CharSequence)
2131 * matcher}(</tt><i>str</i><tt>).{@link java.util.regex.Matcher#replaceFirst
2132 * replaceFirst}(</tt><i>repl</i><tt>)</tt></blockquote>
2133 *
2134 *<p>
2135 * Note that backslashes (<tt>\</tt>) and dollar signs (<tt>$</tt>) in the
2136 * replacement string may cause the results to be different than if it were
2137 * being treated as a literal replacement string; see
2138 * {@link java.util.regex.Matcher#replaceFirst}.
2139 * Use {@link java.util.regex.Matcher#quoteReplacement} to suppress the special
2140 * meaning of these characters, if desired.
2141 *
2142 * @param regex
2143 * the regular expression to which this string is to be matched
2144 * @param replacement
2145 * the string to be substituted for the first match
2146 *
2147 * @return The resulting <tt>String</tt>
2148 *
2149 * @throws PatternSyntaxException
2150 * if the regular expression's syntax is invalid
2151 *
2152 * @see java.util.regex.Pattern
2153 *
2154 * @since 1.4
2155 * @spec JSR-51
2156 */
2157 public String replaceFirst(String regex, String replacement) {
2158 return Pattern.compile(regex).matcher(this).replaceFirst(replacement);
2159 }
2160
2161 /**
2162 * Replaces each substring of this string that matches the given <a
2163 * href="../util/regex/Pattern.html#sum">regular expression</a> with the
2164 * given replacement.
2165 *
2166 * <p> An invocation of this method of the form
2167 * <i>str</i><tt>.replaceAll(</tt><i>regex</i><tt>,</tt> <i>repl</i><tt>)</tt>
2168 * yields exactly the same result as the expression
2169 *
2170 * <blockquote><tt>
2171 * {@link java.util.regex.Pattern}.{@link java.util.regex.Pattern#compile
2172 * compile}(</tt><i>regex</i><tt>).{@link
2173 * java.util.regex.Pattern#matcher(java.lang.CharSequence)
2174 * matcher}(</tt><i>str</i><tt>).{@link java.util.regex.Matcher#replaceAll
2175 * replaceAll}(</tt><i>repl</i><tt>)</tt></blockquote>
2176 *
2177 *<p>
2178 * Note that backslashes (<tt>\</tt>) and dollar signs (<tt>$</tt>) in the
2179 * replacement string may cause the results to be different than if it were
2180 * being treated as a literal replacement string; see
2181 * {@link java.util.regex.Matcher#replaceAll Matcher.replaceAll}.
2182 * Use {@link java.util.regex.Matcher#quoteReplacement} to suppress the special
2183 * meaning of these characters, if desired.
2184 *
2185 * @param regex
2186 * the regular expression to which this string is to be matched
2187 * @param replacement
2188 * the string to be substituted for each match
2189 *
2190 * @return The resulting <tt>String</tt>
2191 *
2192 * @throws PatternSyntaxException
2193 * if the regular expression's syntax is invalid
2194 *
2195 * @see java.util.regex.Pattern
2196 *
2197 * @since 1.4
2198 * @spec JSR-51
2199 */
2200 public String replaceAll(String regex, String replacement) {
2201 return Pattern.compile(regex).matcher(this).replaceAll(replacement);
2202 }
2203
2204 /**
2205 * Replaces each substring of this string that matches the literal target
2206 * sequence with the specified literal replacement sequence. The
2207 * replacement proceeds from the beginning of the string to the end, for
2208 * example, replacing "aa" with "b" in the string "aaa" will result in
2209 * "ba" rather than "ab".
2210 *
2211 * @param target The sequence of char values to be replaced
2212 * @param replacement The replacement sequence of char values
2213 * @return The resulting string
2214 * @throws NullPointerException if <code>target</code> or
2215 * <code>replacement</code> is <code>null</code>.
2216 * @since 1.5
2217 */
2218 public String replace(CharSequence target, CharSequence replacement) {
2219 return Pattern.compile(target.toString(), Pattern.LITERAL).matcher(
2220 this).replaceAll(Matcher.quoteReplacement(replacement.toString()));
2221 }
2222
2223 /**
2224 * Splits this string around matches of the given
2225 * <a href="../util/regex/Pattern.html#sum">regular expression</a>.
2226 *
2227 * <p> The array returned by this method contains each substring of this
2228 * string that is terminated by another substring that matches the given
2229 * expression or is terminated by the end of the string. The substrings in
2230 * the array are in the order in which they occur in this string. If the
2231 * expression does not match any part of the input then the resulting array
2232 * has just one element, namely this string.
2233 *
2234 * <p> The <tt>limit</tt> parameter controls the number of times the
2235 * pattern is applied and therefore affects the length of the resulting
2236 * array. If the limit <i>n</i> is greater than zero then the pattern
2237 * will be applied at most <i>n</i> - 1 times, the array's
2238 * length will be no greater than <i>n</i>, and the array's last entry
2239 * will contain all input beyond the last matched delimiter. If <i>n</i>
2240 * is non-positive then the pattern will be applied as many times as
2241 * possible and the array can have any length. If <i>n</i> is zero then
2242 * the pattern will be applied as many times as possible, the array can
2243 * have any length, and trailing empty strings will be discarded.
2244 *
2245 * <p> The string <tt>"boo:and:foo"</tt>, for example, yields the
2246 * following results with these parameters:
2247 *
2248 * <blockquote><table cellpadding=1 cellspacing=0 summary="Split example showing regex, limit, and result">
2249 * <tr>
2250 * <th>Regex</th>
2251 * <th>Limit</th>
2252 * <th>Result</th>
2253 * </tr>
2254 * <tr><td align=center>:</td>
2255 * <td align=center>2</td>
2256 * <td><tt>{ "boo", "and:foo" }</tt></td></tr>
2257 * <tr><td align=center>:</td>
2258 * <td align=center>5</td>
2259 * <td><tt>{ "boo", "and", "foo" }</tt></td></tr>
2260 * <tr><td align=center>:</td>
2261 * <td align=center>-2</td>
2262 * <td><tt>{ "boo", "and", "foo" }</tt></td></tr>
2263 * <tr><td align=center>o</td>
2264 * <td align=center>5</td>
2265 * <td><tt>{ "b", "", ":and:f", "", "" }</tt></td></tr>
2266 * <tr><td align=center>o</td>
2267 * <td align=center>-2</td>
2268 * <td><tt>{ "b", "", ":and:f", "", "" }</tt></td></tr>
2269 * <tr><td align=center>o</td>
2270 * <td align=center>0</td>
2271 * <td><tt>{ "b", "", ":and:f" }</tt></td></tr>
2272 * </table></blockquote>
2273 *
2274 * <p> An invocation of this method of the form
2275 * <i>str.</i><tt>split(</tt><i>regex</i><tt>,</tt> <i>n</i><tt>)</tt>
2276 * yields the same result as the expression
2277 *
2278 * <blockquote>
2279 * {@link java.util.regex.Pattern}.{@link java.util.regex.Pattern#compile
2280 * compile}<tt>(</tt><i>regex</i><tt>)</tt>.{@link
2281 * java.util.regex.Pattern#split(java.lang.CharSequence,int)
2282 * split}<tt>(</tt><i>str</i><tt>,</tt> <i>n</i><tt>)</tt>
2283 * </blockquote>
2284 *
2285 *
2286 * @param regex
2287 * the delimiting regular expression
2288 *
2289 * @param limit
2290 * the result threshold, as described above
2291 *
2292 * @return the array of strings computed by splitting this string
2293 * around matches of the given regular expression
2294 *
2295 * @throws PatternSyntaxException
2296 * if the regular expression's syntax is invalid
2297 *
2298 * @see java.util.regex.Pattern
2299 *
2300 * @since 1.4
2301 * @spec JSR-51
2302 */
2303 public String[] split(String regex, int limit) {
2304 return Pattern.compile(regex).split(this, limit);
2305 }
2306
2307 /**
2308 * Splits this string around matches of the given <a
2309 * href="../util/regex/Pattern.html#sum">regular expression</a>.
2310 *
2311 * <p> This method works as if by invoking the two-argument {@link
2312 * #split(String, int) split} method with the given expression and a limit
2313 * argument of zero. Trailing empty strings are therefore not included in
2314 * the resulting array.
2315 *
2316 * <p> The string <tt>"boo:and:foo"</tt>, for example, yields the following
2317 * results with these expressions:
2318 *
2319 * <blockquote><table cellpadding=1 cellspacing=0 summary="Split examples showing regex and result">
2320 * <tr>
2321 * <th>Regex</th>
2322 * <th>Result</th>
2323 * </tr>
2324 * <tr><td align=center>:</td>
2325 * <td><tt>{ "boo", "and", "foo" }</tt></td></tr>
2326 * <tr><td align=center>o</td>
2327 * <td><tt>{ "b", "", ":and:f" }</tt></td></tr>
2328 * </table></blockquote>
2329 *
2330 *
2331 * @param regex
2332 * the delimiting regular expression
2333 *
2334 * @return the array of strings computed by splitting this string
2335 * around matches of the given regular expression
2336 *
2337 * @throws PatternSyntaxException
2338 * if the regular expression's syntax is invalid
2339 *
2340 * @see java.util.regex.Pattern
2341 *
2342 * @since 1.4
2343 * @spec JSR-51
2344 */
2345 public String[] split(String regex) {
2346 return split(regex, 0);
2347 }
2348
2349 /**
2350 * Converts all of the characters in this <code>String</code> to lower
2351 * case using the rules of the given <code>Locale</code>. Case mapping is based
2352 * on the Unicode Standard version specified by the {@link java.lang.Character Character}
2353 * class. Since case mappings are not always 1:1 char mappings, the resulting
2354 * <code>String</code> may be a different length than the original <code>String</code>.
2355 * <p>
2356 * Examples of lowercase mappings are in the following table:
2357 * <table border="1" summary="Lowercase mapping examples showing language code of locale, upper case, lower case, and description">
2358 * <tr>
2359 * <th>Language Code of Locale</th>
2360 * <th>Upper Case</th>
2361 * <th>Lower Case</th>
2362 * <th>Description</th>
2363 * </tr>
2364 * <tr>
2365 * <td>tr (Turkish)</td>
2366 * <td>\u0130</td>
2367 * <td>\u0069</td>
2368 * <td>capital letter I with dot above -> small letter i</td>
2369 * </tr>
2370 * <tr>
2371 * <td>tr (Turkish)</td>
2372 * <td>\u0049</td>
2373 * <td>\u0131</td>
2374 * <td>capital letter I -> small letter dotless i </td>
2375 * </tr>
2376 * <tr>
2377 * <td>(all)</td>
2378 * <td>French Fries</td>
2379 * <td>french fries</td>
2380 * <td>lowercased all chars in String</td>
2381 * </tr>
2382 * <tr>
2383 * <td>(all)</td>
2384 * <td><img src="doc-files/capiota.gif" alt="capiota"><img src="doc-files/capchi.gif" alt="capchi">
2385 * <img src="doc-files/captheta.gif" alt="captheta"><img src="doc-files/capupsil.gif" alt="capupsil">
2386 * <img src="doc-files/capsigma.gif" alt="capsigma"></td>
2387 * <td><img src="doc-files/iota.gif" alt="iota"><img src="doc-files/chi.gif" alt="chi">
2388 * <img src="doc-files/theta.gif" alt="theta"><img src="doc-files/upsilon.gif" alt="upsilon">
2389 * <img src="doc-files/sigma1.gif" alt="sigma"></td>
2390 * <td>lowercased all chars in String</td>
2391 * </tr>
2392 * </table>
2393 *
2394 * @param locale use the case transformation rules for this locale
2395 * @return the <code>String</code>, converted to lowercase.
2396 * @see java.lang.String#toLowerCase()
2397 * @see java.lang.String#toUpperCase()
2398 * @see java.lang.String#toUpperCase(Locale)
2399 * @since 1.1
2400 */
2401 public String toLowerCase(Locale locale) {
2402 if (locale == null) {
2403 throw new NullPointerException();
2404 }
2405
2406 int firstUpper;
2407
2408 /* Now check if there are any characters that need to be changed. */
2409 scan: {
2410 for (firstUpper = 0 ; firstUpper < count; ) {
2411 char c = value[offset+firstUpper];
2412 if ((c >= Character.MIN_HIGH_SURROGATE) &&
2413 (c <= Character.MAX_HIGH_SURROGATE)) {
2414 int supplChar = codePointAt(firstUpper);
2415 if (supplChar != Character.toLowerCase(supplChar)) {
2416 break scan;
2417 }
2418 firstUpper += Character.charCount(supplChar);
2419 } else {
2420 if (c != Character.toLowerCase(c)) {
2421 break scan;
2422 }
2423 firstUpper++;
2424 }
2425 }
2426 return this;
2427 }
2428
2429 char[] result = new char[count];
2430 int resultOffset = 0; /* result may grow, so i+resultOffset
2431 * is the write location in result */
2432
2433 /* Just copy the first few lowerCase characters. */
2434 System.arraycopy(value, offset, result, 0, firstUpper);
2435
2436 String lang = locale.getLanguage();
2437 boolean localeDependent =
2438 (lang == "tr" || lang == "az" || lang == "lt");
2439 char[] lowerCharArray;
2440 int lowerChar;
2441 int srcChar;
2442 int srcCount;
2443 for (int i = firstUpper; i < count; i += srcCount) {
2444 srcChar = (int)value[offset+i];
2445 if ((char)srcChar >= Character.MIN_HIGH_SURROGATE &&
2446 (char)srcChar <= Character.MAX_HIGH_SURROGATE) {
2447 srcChar = codePointAt(i);
2448 srcCount = Character.charCount(srcChar);
2449 } else {
2450 srcCount = 1;
2451 }
2452 if (localeDependent || srcChar == '\u03A3') { // GREEK CAPITAL LETTER SIGMA
2453 lowerChar = ConditionalSpecialCasing.toLowerCaseEx(this, i, locale);
2454 } else {
2455 lowerChar = Character.toLowerCase(srcChar);
2456 }
2457 if ((lowerChar == Character.ERROR) ||
2458 (lowerChar >= Character.MIN_SUPPLEMENTARY_CODE_POINT)) {
2459 if (lowerChar == Character.ERROR) {
2460 lowerCharArray =
2461 ConditionalSpecialCasing.toLowerCaseCharArray(this, i, locale);
2462 } else if (srcCount == 2) {
2463 resultOffset += Character.toChars(lowerChar, result, i + resultOffset) - srcCount;
2464 continue;
2465 } else {
2466 lowerCharArray = Character.toChars(lowerChar);
2467 }
2468
2469 /* Grow result if needed */
2470 int mapLen = lowerCharArray.length;
2471 if (mapLen > srcCount) {
2472 char[] result2 = new char[result.length + mapLen - srcCount];
2473 System.arraycopy(result, 0, result2, 0,
2474 i + resultOffset);
2475 result = result2;
2476 }
2477 for (int x=0; x<mapLen; ++x) {
2478 result[i+resultOffset+x] = lowerCharArray[x];
2479 }
2480 resultOffset += (mapLen - srcCount);
2481 } else {
2482 result[i+resultOffset] = (char)lowerChar;
2483 }
2484 }
2485 return new String(0, count+resultOffset, result);
2486 }
2487
2488 /**
2489 * Converts all of the characters in this <code>String</code> to lower
2490 * case using the rules of the default locale. This is equivalent to calling
2491 * <code>toLowerCase(Locale.getDefault())</code>.
2492 * <p>
2493 * <b>Note:</b> This method is locale sensitive, and may produce unexpected
2494 * results if used for strings that are intended to be interpreted locale
2495 * independently.
2496 * Examples are programming language identifiers, protocol keys, and HTML
2497 * tags.
2498 * For instance, <code>"TITLE".toLowerCase()</code> in a Turkish locale
2499 * returns <code>"t\u0131tle"</code>, where '\u0131' is the LATIN SMALL
2500 * LETTER DOTLESS I character.
2501 * To obtain correct results for locale insensitive strings, use
2502 * <code>toLowerCase(Locale.ENGLISH)</code>.
2503 * <p>
2504 * @return the <code>String</code>, converted to lowercase.
2505 * @see java.lang.String#toLowerCase(Locale)
2506 */
2507 public String toLowerCase() {
2508 return toLowerCase(Locale.getDefault());
2509 }
2510
2511 /**
2512 * Converts all of the characters in this <code>String</code> to upper
2513 * case using the rules of the given <code>Locale</code>. Case mapping is based
2514 * on the Unicode Standard version specified by the {@link java.lang.Character Character}
2515 * class. Since case mappings are not always 1:1 char mappings, the resulting
2516 * <code>String</code> may be a different length than the original <code>String</code>.
2517 * <p>
2518 * Examples of locale-sensitive and 1:M case mappings are in the following table.
2519 * <p>
2520 * <table border="1" summary="Examples of locale-sensitive and 1:M case mappings. Shows Language code of locale, lower case, upper case, and description.">
2521 * <tr>
2522 * <th>Language Code of Locale</th>
2523 * <th>Lower Case</th>
2524 * <th>Upper Case</th>
2525 * <th>Description</th>
2526 * </tr>
2527 * <tr>
2528 * <td>tr (Turkish)</td>
2529 * <td>\u0069</td>
2530 * <td>\u0130</td>
2531 * <td>small letter i -> capital letter I with dot above</td>
2532 * </tr>
2533 * <tr>
2534 * <td>tr (Turkish)</td>
2535 * <td>\u0131</td>
2536 * <td>\u0049</td>
2537 * <td>small letter dotless i -> capital letter I</td>
2538 * </tr>
2539 * <tr>
2540 * <td>(all)</td>
2541 * <td>\u00df</td>
2542 * <td>\u0053 \u0053</td>
2543 * <td>small letter sharp s -> two letters: SS</td>
2544 * </tr>
2545 * <tr>
2546 * <td>(all)</td>
2547 * <td>Fahrvergnügen</td>
2548 * <td>FAHRVERGNÜGEN</td>
2549 * <td></td>
2550 * </tr>
2551 * </table>
2552 * @param locale use the case transformation rules for this locale
2553 * @return the <code>String</code>, converted to uppercase.
2554 * @see java.lang.String#toUpperCase()
2555 * @see java.lang.String#toLowerCase()
2556 * @see java.lang.String#toLowerCase(Locale)
2557 * @since 1.1
2558 */
2559 public String toUpperCase(Locale locale) {
2560 if (locale == null) {
2561 throw new NullPointerException();
2562 }
2563
2564 int firstLower;
2565
2566 /* Now check if there are any characters that need to be changed. */
2567 scan: {
2568 for (firstLower = 0 ; firstLower < count; ) {
2569 int c = (int)value[offset+firstLower];
2570 int srcCount;
2571 if ((c >= Character.MIN_HIGH_SURROGATE) &&
2572 (c <= Character.MAX_HIGH_SURROGATE)) {
2573 c = codePointAt(firstLower);
2574 srcCount = Character.charCount(c);
2575 } else {
2576 srcCount = 1;
2577 }
2578 int upperCaseChar = Character.toUpperCaseEx(c);
2579 if ((upperCaseChar == Character.ERROR) ||
2580 (c != upperCaseChar)) {
2581 break scan;
2582 }
2583 firstLower += srcCount;
2584 }
2585 return this;
2586 }
2587
2588 char[] result = new char[count]; /* may grow */
2589 int resultOffset = 0; /* result may grow, so i+resultOffset
2590 * is the write location in result */
2591
2592 /* Just copy the first few upperCase characters. */
2593 System.arraycopy(value, offset, result, 0, firstLower);
2594
2595 String lang = locale.getLanguage();
2596 boolean localeDependent =
2597 (lang == "tr" || lang == "az" || lang == "lt");
2598 char[] upperCharArray;
2599 int upperChar;
2600 int srcChar;
2601 int srcCount;
2602 for (int i = firstLower; i < count; i += srcCount) {
2603 srcChar = (int)value[offset+i];
2604 if ((char)srcChar >= Character.MIN_HIGH_SURROGATE &&
2605 (char)srcChar <= Character.MAX_HIGH_SURROGATE) {
2606 srcChar = codePointAt(i);
2607 srcCount = Character.charCount(srcChar);
2608 } else {
2609 srcCount = 1;
2610 }
2611 if (localeDependent) {
2612 upperChar = ConditionalSpecialCasing.toUpperCaseEx(this, i, locale);
2613 } else {
2614 upperChar = Character.toUpperCaseEx(srcChar);
2615 }
2616 if ((upperChar == Character.ERROR) ||
2617 (upperChar >= Character.MIN_SUPPLEMENTARY_CODE_POINT)) {
2618 if (upperChar == Character.ERROR) {
2619 if (localeDependent) {
2620 upperCharArray =
2621 ConditionalSpecialCasing.toUpperCaseCharArray(this, i, locale);
2622 } else {
2623 upperCharArray = Character.toUpperCaseCharArray(srcChar);
2624 }
2625 } else if (srcCount == 2) {
2626 resultOffset += Character.toChars(upperChar, result, i + resultOffset) - srcCount;
2627 continue;
2628 } else {
2629 upperCharArray = Character.toChars(upperChar);
2630 }
2631
2632 /* Grow result if needed */
2633 int mapLen = upperCharArray.length;
2634 if (mapLen > srcCount) {
2635 char[] result2 = new char[result.length + mapLen - srcCount];
2636 System.arraycopy(result, 0, result2, 0,
2637 i + resultOffset);
2638 result = result2;
2639 }
2640 for (int x=0; x<mapLen; ++x) {
2641 result[i+resultOffset+x] = upperCharArray[x];
2642 }
2643 resultOffset += (mapLen - srcCount);
2644 } else {
2645 result[i+resultOffset] = (char)upperChar;
2646 }
2647 }
2648 return new String(0, count+resultOffset, result);
2649 }
2650
2651 /**
2652 * Converts all of the characters in this <code>String</code> to upper
2653 * case using the rules of the default locale. This method is equivalent to
2654 * <code>toUpperCase(Locale.getDefault())</code>.
2655 * <p>
2656 * <b>Note:</b> This method is locale sensitive, and may produce unexpected
2657 * results if used for strings that are intended to be interpreted locale
2658 * independently.
2659 * Examples are programming language identifiers, protocol keys, and HTML
2660 * tags.
2661 * For instance, <code>"title".toUpperCase()</code> in a Turkish locale
2662 * returns <code>"T\u0130TLE"</code>, where '\u0130' is the LATIN CAPITAL
2663 * LETTER I WITH DOT ABOVE character.
2664 * To obtain correct results for locale insensitive strings, use
2665 * <code>toUpperCase(Locale.ENGLISH)</code>.
2666 * <p>
2667 * @return the <code>String</code>, converted to uppercase.
2668 * @see java.lang.String#toUpperCase(Locale)
2669 */
2670 public String toUpperCase() {
2671 return toUpperCase(Locale.getDefault());
2672 }
2673
2674 /**
2675 * Returns a copy of the string, with leading and trailing whitespace
2676 * omitted.
2677 * <p>
2678 * If this <code>String</code> object represents an empty character
2679 * sequence, or the first and last characters of character sequence
2680 * represented by this <code>String</code> object both have codes
2681 * greater than <code>'\u0020'</code> (the space character), then a
2682 * reference to this <code>String</code> object is returned.
2683 * <p>
2684 * Otherwise, if there is no character with a code greater than
2685 * <code>'\u0020'</code> in the string, then a new
2686 * <code>String</code> object representing an empty string is created
2687 * and returned.
2688 * <p>
2689 * Otherwise, let <i>k</i> be the index of the first character in the
2690 * string whose code is greater than <code>'\u0020'</code>, and let
2691 * <i>m</i> be the index of the last character in the string whose code
2692 * is greater than <code>'\u0020'</code>. A new <code>String</code>
2693 * object is created, representing the substring of this string that
2694 * begins with the character at index <i>k</i> and ends with the
2695 * character at index <i>m</i>-that is, the result of
2696 * <code>this.substring(<i>k</i>, <i>m</i>+1)</code>.
2697 * <p>
2698 * This method may be used to trim whitespace (as defined above) from
2699 * the beginning and end of a string.
2700 *
2701 * @return A copy of this string with leading and trailing white
2702 * space removed, or this string if it has no leading or
2703 * trailing white space.
2704 */
2705 public String trim() {
2706 int len = count;
2707 int st = 0;
2708 int off = offset; /* avoid getfield opcode */
2709 char[] val = value; /* avoid getfield opcode */
2710
2711 while ((st < len) && (val[off + st] <= ' ')) {
2712 st++;
2713 }
2714 while ((st < len) && (val[off + len - 1] <= ' ')) {
2715 len--;
2716 }
2717 return ((st > 0) || (len < count)) ? substring(st, len) : this;
2718 }
2719
2720 /**
2721 * This object (which is already a string!) is itself returned.
2722 *
2723 * @return the string itself.
2724 */
2725 public String toString() {
2726 return this;
2727 }
2728
2729 /**
2730 * Converts this string to a new character array.
2731 *
2732 * @return a newly allocated character array whose length is the length
2733 * of this string and whose contents are initialized to contain
2734 * the character sequence represented by this string.
2735 */
2736 public char[] toCharArray() {
2737 char result[] = new char[count];
2738 getChars(0, count, result, 0);
2739 return result;
2740 }
2741
2742 /**
2743 * Returns a formatted string using the specified format string and
2744 * arguments.
2745 *
2746 * <p> The locale always used is the one returned by {@link
2747 * java.util.Locale#getDefault() Locale.getDefault()}.
2748 *
2749 * @param format
2750 * A <a href="../util/Formatter.html#syntax">format string</a>
2751 *
2752 * @param args
2753 * Arguments referenced by the format specifiers in the format
2754 * string. If there are more arguments than format specifiers, the
2755 * extra arguments are ignored. The number of arguments is
2756 * variable and may be zero. The maximum number of arguments is
2757 * limited by the maximum dimension of a Java array as defined by
2758 * the <a href="http://java.sun.com/docs/books/vmspec/">Java
2759 * Virtual Machine Specification</a>. The behaviour on a
2760 * <tt>null</tt> argument depends on the <a
2761 * href="../util/Formatter.html#syntax">conversion</a>.
2762 *
2763 * @throws IllegalFormatException
2764 * If a format string contains an illegal syntax, a format
2765 * specifier that is incompatible with the given arguments,
2766 * insufficient arguments given the format string, or other
2767 * illegal conditions. For specification of all possible
2768 * formatting errors, see the <a
2769 * href="../util/Formatter.html#detail">Details</a> section of the
2770 * formatter class specification.
2771 *
2772 * @throws NullPointerException
2773 * If the <tt>format</tt> is <tt>null</tt>
2774 *
2775 * @return A formatted string
2776 *
2777 * @see java.util.Formatter
2778 * @since 1.5
2779 */
2780 public static String format(String format, Object ... args) {
2781 return new Formatter().format(format, args).toString();
2782 }
2783
2784 /**
2785 * Returns a formatted string using the specified locale, format string,
2786 * and arguments.
2787 *
2788 * @param l
2789 * The {@linkplain java.util.Locale locale} to apply during
2790 * formatting. If <tt>l</tt> is <tt>null</tt> then no localization
2791 * is applied.
2792 *
2793 * @param format
2794 * A <a href="../util/Formatter.html#syntax">format string</a>
2795 *
2796 * @param args
2797 * Arguments referenced by the format specifiers in the format
2798 * string. If there are more arguments than format specifiers, the
2799 * extra arguments are ignored. The number of arguments is
2800 * variable and may be zero. The maximum number of arguments is
2801 * limited by the maximum dimension of a Java array as defined by
2802 * the <a href="http://java.sun.com/docs/books/vmspec/">Java
2803 * Virtual Machine Specification</a>. The behaviour on a
2804 * <tt>null</tt> argument depends on the <a
2805 * href="../util/Formatter.html#syntax">conversion</a>.
2806 *
2807 * @throws IllegalFormatException
2808 * If a format string contains an illegal syntax, a format
2809 * specifier that is incompatible with the given arguments,
2810 * insufficient arguments given the format string, or other
2811 * illegal conditions. For specification of all possible
2812 * formatting errors, see the <a
2813 * href="../util/Formatter.html#detail">Details</a> section of the
2814 * formatter class specification
2815 *
2816 * @throws NullPointerException
2817 * If the <tt>format</tt> is <tt>null</tt>
2818 *
2819 * @return A formatted string
2820 *
2821 * @see java.util.Formatter
2822 * @since 1.5
2823 */
2824 public static String format(Locale l, String format, Object ... args) {
2825 return new Formatter(l).format(format, args).toString();
2826 }
2827
2828 /**
2829 * Returns the string representation of the <code>Object</code> argument.
2830 *
2831 * @param obj an <code>Object</code>.
2832 * @return if the argument is <code>null</code>, then a string equal to
2833 * <code>"null"</code>; otherwise, the value of
2834 * <code>obj.toString()</code> is returned.
2835 * @see java.lang.Object#toString()
2836 */
2837 public static String valueOf(Object obj) {
2838 return (obj == null) ? "null" : obj.toString();
2839 }
2840
2841 /**
2842 * Returns the string representation of the <code>char</code> array
2843 * argument. The contents of the character array are copied; subsequent
2844 * modification of the character array does not affect the newly
2845 * created string.
2846 *
2847 * @param data a <code>char</code> array.
2848 * @return a newly allocated string representing the same sequence of
2849 * characters contained in the character array argument.
2850 */
2851 public static String valueOf(char data[]) {
2852 return new String(data);
2853 }
2854
2855 /**
2856 * Returns the string representation of a specific subarray of the
2857 * <code>char</code> array argument.
2858 * <p>
2859 * The <code>offset</code> argument is the index of the first
2860 * character of the subarray. The <code>count</code> argument
2861 * specifies the length of the subarray. The contents of the subarray
2862 * are copied; subsequent modification of the character array does not
2863 * affect the newly created string.
2864 *
2865 * @param data the character array.
2866 * @param offset the initial offset into the value of the
2867 * <code>String</code>.
2868 * @param count the length of the value of the <code>String</code>.
2869 * @return a string representing the sequence of characters contained
2870 * in the subarray of the character array argument.
2871 * @exception IndexOutOfBoundsException if <code>offset</code> is
2872 * negative, or <code>count</code> is negative, or
2873 * <code>offset+count</code> is larger than
2874 * <code>data.length</code>.
2875 */
2876 public static String valueOf(char data[], int offset, int count) {
2877 return new String(data, offset, count);
2878 }
2879
2880 /**
2881 * Returns a String that represents the character sequence in the
2882 * array specified.
2883 *
2884 * @param data the character array.
2885 * @param offset initial offset of the subarray.
2886 * @param count length of the subarray.
2887 * @return a <code>String</code> that contains the characters of the
2888 * specified subarray of the character array.
2889 */
2890 public static String copyValueOf(char data[], int offset, int count) {
2891 // All public String constructors now copy the data.
2892 return new String(data, offset, count);
2893 }
2894
2895 /**
2896 * Returns a String that represents the character sequence in the
2897 * array specified.
2898 *
2899 * @param data the character array.
2900 * @return a <code>String</code> that contains the characters of the
2901 * character array.
2902 */
2903 public static String copyValueOf(char data[]) {
2904 return copyValueOf(data, 0, data.length);
2905 }
2906
2907 /**
2908 * Returns the string representation of the <code>boolean</code> argument.
2909 *
2910 * @param b a <code>boolean</code>.
2911 * @return if the argument is <code>true</code>, a string equal to
2912 * <code>"true"</code> is returned; otherwise, a string equal to
2913 * <code>"false"</code> is returned.
2914 */
2915 public static String valueOf(boolean b) {
2916 return b ? "true" : "false";
2917 }
2918
2919 /**
2920 * Returns the string representation of the <code>char</code>
2921 * argument.
2922 *
2923 * @param c a <code>char</code>.
2924 * @return a string of length <code>1</code> containing
2925 * as its single character the argument <code>c</code>.
2926 */
2927 public static String valueOf(char c) {
2928 char data[] = {c};
2929 return new String(0, 1, data);
2930 }
2931
2932 /**
2933 * Returns the string representation of the <code>int</code> argument.
2934 * <p>
2935 * The representation is exactly the one returned by the
2936 * <code>Integer.toString</code> method of one argument.
2937 *
2938 * @param i an <code>int</code>.
2939 * @return a string representation of the <code>int</code> argument.
2940 * @see java.lang.Integer#toString(int, int)
2941 */
2942 public static String valueOf(int i) {
2943 return Integer.toString(i, 10);
2944 }
2945
2946 /**
2947 * Returns the string representation of the <code>long</code> argument.
2948 * <p>
2949 * The representation is exactly the one returned by the
2950 * <code>Long.toString</code> method of one argument.
2951 *
2952 * @param l a <code>long</code>.
2953 * @return a string representation of the <code>long</code> argument.
2954 * @see java.lang.Long#toString(long)
2955 */
2956 public static String valueOf(long l) {
2957 return Long.toString(l, 10);
2958 }
2959
2960 /**
2961 * Returns the string representation of the <code>float</code> argument.
2962 * <p>
2963 * The representation is exactly the one returned by the
2964 * <code>Float.toString</code> method of one argument.
2965 *
2966 * @param f a <code>float</code>.
2967 * @return a string representation of the <code>float</code> argument.
2968 * @see java.lang.Float#toString(float)
2969 */
2970 public static String valueOf(float f) {
2971 return Float.toString(f);
2972 }
2973
2974 /**
2975 * Returns the string representation of the <code>double</code> argument.
2976 * <p>
2977 * The representation is exactly the one returned by the
2978 * <code>Double.toString</code> method of one argument.
2979 *
2980 * @param d a <code>double</code>.
2981 * @return a string representation of the <code>double</code> argument.
2982 * @see java.lang.Double#toString(double)
2983 */
2984 public static String valueOf(double d) {
2985 return Double.toString(d);
2986 }
2987
2988 /**
2989 * Returns a canonical representation for the string object.
2990 * <p>
2991 * A pool of strings, initially empty, is maintained privately by the
2992 * class <code>String</code>.
2993 * <p>
2994 * When the intern method is invoked, if the pool already contains a
2995 * string equal to this <code>String</code> object as determined by
2996 * the {@link #equals(Object)} method, then the string from the pool is
2997 * returned. Otherwise, this <code>String</code> object is added to the
2998 * pool and a reference to this <code>String</code> object is returned.
2999 * <p>
3000 * It follows that for any two strings <code>s</code> and <code>t</code>,
3001 * <code>s.intern() == t.intern()</code> is <code>true</code>
3002 * if and only if <code>s.equals(t)</code> is <code>true</code>.
3003 * <p>
3004 * All literal strings and string-valued constant expressions are
3005 * interned. String literals are defined in §3.10.5 of the
3006 * <a href="http://java.sun.com/docs/books/jls/html/">Java Language
3007 * Specification</a>
3008 *
3009 * @return a string that has the same contents as this string, but is
3010 * guaranteed to be from a pool of unique strings.
3011 */
3012 public native String intern();
3013
3014 }
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