1 /*
2 * Copyright (c) 1994, 2010, Oracle and/or its affiliates. All rights reserved.
3 * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.
4 *
5 * This code is free software; you can redistribute it and/or modify it
6 * under the terms of the GNU General Public License version 2 only, as
7 * published by the Free Software Foundation. Oracle designates this
8 * particular file as subject to the "Classpath" exception as provided
9 * by Oracle in the LICENSE file that accompanied this code.
10 *
11 * This code is distributed in the hope that it will be useful, but WITHOUT
12 * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
13 * FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License
14 * version 2 for more details (a copy is included in the LICENSE file that
15 * accompanied this code).
16 *
17 * You should have received a copy of the GNU General Public License version
18 * 2 along with this work; if not, write to the Free Software Foundation,
19 * Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA.
20 *
21 * Please contact Oracle, 500 Oracle Parkway, Redwood Shores, CA 94065 USA
22 * or visit www.oracle.com if you need additional information or have any
23 * questions.
24 */
25
26 package java.lang;
27
28 import java.io.ObjectStreamField;
29 import java.io.UnsupportedEncodingException;
30 import java.nio.charset.Charset;
31 import java.util.ArrayList;
32 import java.util.Arrays;
33 import java.util.Comparator;
34 import java.util.Formatter;
35 import java.util.Locale;
36 import java.util.regex.Matcher;
37 import java.util.regex.Pattern;
38 import java.util.regex.PatternSyntaxException;
39
40 /**
41 * The {@code String} class represents character strings. All
42 * string literals in Java programs, such as {@code "abc"}, are
43 * implemented as instances of this class.
44 * <p>
45 * Strings are constant; their values cannot be changed after they
46 * are created. String buffers support mutable strings.
47 * Because String objects are immutable they can be shared. For example:
48 * <p><blockquote><pre>
49 * String str = "abc";
50 * </pre></blockquote><p>
51 * is equivalent to:
52 * <p><blockquote><pre>
53 * char data[] = {'a', 'b', 'c'};
54 * String str = new String(data);
55 * </pre></blockquote><p>
56 * Here are some more examples of how strings can be used:
57 * <p><blockquote><pre>
58 * System.out.println("abc");
59 * String cde = "cde";
60 * System.out.println("abc" + cde);
61 * String c = "abc".substring(2,3);
62 * String d = cde.substring(1, 2);
63 * </pre></blockquote>
64 * <p>
65 * The class {@code String} includes methods for examining
66 * individual characters of the sequence, for comparing strings, for
67 * searching strings, for extracting substrings, and for creating a
68 * copy of a string with all characters translated to uppercase or to
69 * lowercase. Case mapping is based on the Unicode Standard version
70 * specified by the {@link java.lang.Character Character} class.
71 * <p>
72 * The Java language provides special support for the string
73 * concatenation operator ( + ), and for conversion of
74 * other objects to strings. String concatenation is implemented
75 * through the {@code StringBuilder}(or {@code StringBuffer})
76 * class and its {@code append} method.
77 * String conversions are implemented through the method
78 * {@code toString}, defined by {@code Object} and
79 * inherited by all classes in Java. For additional information on
80 * string concatenation and conversion, see Gosling, Joy, and Steele,
81 * <i>The Java Language Specification</i>.
82 *
83 * <p> Unless otherwise noted, passing a <tt>null</tt> argument to a constructor
84 * or method in this class will cause a {@link NullPointerException} to be
85 * thrown.
86 *
87 * <p>A {@code String} represents a string in the UTF-16 format
88 * in which <em>supplementary characters</em> are represented by <em>surrogate
89 * pairs</em> (see the section <a href="Character.html#unicode">Unicode
90 * Character Representations</a> in the {@code Character} class for
91 * more information).
92 * Index values refer to {@code char} code units, so a supplementary
93 * character uses two positions in a {@code String}.
94 * <p>The {@code String} class provides methods for dealing with
95 * Unicode code points (i.e., characters), in addition to those for
96 * dealing with Unicode code units (i.e., {@code char} values).
97 *
98 * @author Lee Boynton
99 * @author Arthur van Hoff
100 * @author Martin Buchholz
101 * @author Ulf Zibis
102 * @see java.lang.Object#toString()
103 * @see java.lang.StringBuffer
104 * @see java.lang.StringBuilder
105 * @see java.nio.charset.Charset
106 * @since JDK1.0
107 */
108
109 public final class String
110 implements java.io.Serializable, Comparable<String>, CharSequence {
111 /** The value is used for character storage. */
112 private final char value[];
113
114 /** Cache the hash code for the string */
115 private int hash; // Default to 0
116
117 /** use serialVersionUID from JDK 1.0.2 for interoperability */
118 private static final long serialVersionUID = -6849794470754667710L;
119
120 /**
121 * Class String is special cased within the Serialization Stream Protocol.
122 *
123 * A String instance is written initially into an ObjectOutputStream in the
124 * following format:
125 * <pre>
126 * {@code TC_STRING} (utf String)
127 * </pre>
128 * The String is written by method {@code DataOutput.writeUTF}.
129 * A new handle is generated to refer to all future references to the
130 * string instance within the stream.
131 */
132 private static final ObjectStreamField[] serialPersistentFields =
133 new ObjectStreamField[0];
134
135 /**
136 * Initializes a newly created {@code String} object so that it represents
137 * an empty character sequence. Note that use of this constructor is
138 * unnecessary since Strings are immutable.
139 */
140 public String() {
141 this.value = new char[0];
142 }
143
144 /**
145 * Initializes a newly created {@code String} object so that it represents
146 * the same sequence of characters as the argument; in other words, the
147 * newly created string is a copy of the argument string. Unless an
148 * explicit copy of {@code original} is needed, use of this constructor is
149 * unnecessary since Strings are immutable.
150 *
151 * @param original
152 * A {@code String}
153 */
154 public String(String original) {
155 this.value = original.value;
156 this.hash = original.hash;
157 }
158
159 /**
160 * Allocates a new {@code String} so that it represents the sequence of
161 * characters currently contained in the character array argument. The
162 * contents of the character array are copied; subsequent modification of
163 * the character array does not affect the newly created string.
164 *
165 * @param value
166 * The initial value of the string
167 */
168 public String(char value[]) {
169 this.value = Arrays.copyOf(value, value.length);
170 }
171
172 /**
173 * Allocates a new {@code String} that contains characters from a subarray
174 * of the character array argument. The {@code offset} argument is the
175 * index of the first character of the subarray and the {@code count}
176 * argument specifies the length of the subarray. The contents of the
177 * subarray are copied; subsequent modification of the character array does
178 * not affect the newly created string.
179 *
180 * @param value
181 * Array that is the source of characters
182 *
183 * @param offset
184 * The initial offset
185 *
186 * @param count
187 * The length
188 *
189 * @throws IndexOutOfBoundsException
190 * If the {@code offset} and {@code count} arguments index
191 * characters outside the bounds of the {@code value} array
192 */
193 public String(char value[], int offset, int count) {
194 if (offset < 0) {
195 throw new StringIndexOutOfBoundsException(offset);
196 }
197 if (count < 0) {
198 throw new StringIndexOutOfBoundsException(count);
199 }
200 // Note: offset or count might be near -1>>>1.
201 if (offset > value.length - count) {
202 throw new StringIndexOutOfBoundsException(offset + count);
203 }
204 this.value = Arrays.copyOfRange(value, offset, offset+count);
205 }
206
207 /**
208 * Allocates a new {@code String} that contains characters from a subarray
209 * of the <a href="Character.html#unicode">Unicode code point</a> array
210 * argument. The {@code offset} argument is the index of the first code
211 * point of the subarray and the {@code count} argument specifies the
212 * length of the subarray. The contents of the subarray are converted to
213 * {@code char}s; subsequent modification of the {@code int} array does not
214 * affect the newly created string.
215 *
216 * @param codePoints
217 * Array that is the source of Unicode code points
218 *
219 * @param offset
220 * The initial offset
221 *
222 * @param count
223 * The length
224 *
225 * @throws IllegalArgumentException
226 * If any invalid Unicode code point is found in {@code
227 * codePoints}
228 *
229 * @throws IndexOutOfBoundsException
230 * If the {@code offset} and {@code count} arguments index
231 * characters outside the bounds of the {@code codePoints} array
232 *
233 * @since 1.5
234 */
235 public String(int[] codePoints, int offset, int count) {
236 if (offset < 0) {
237 throw new StringIndexOutOfBoundsException(offset);
238 }
239 if (count < 0) {
240 throw new StringIndexOutOfBoundsException(count);
241 }
242 // Note: offset or count might be near -1>>>1.
243 if (offset > codePoints.length - count) {
244 throw new StringIndexOutOfBoundsException(offset + count);
245 }
246
247 final int end = offset + count;
248
249 // Pass 1: Compute precise size of char[]
250 int n = count;
251 for (int i = offset; i < end; i++) {
252 int c = codePoints[i];
253 if (Character.isBmpCodePoint(c))
254 continue;
255 else if (Character.isValidCodePoint(c))
256 n++;
257 else throw new IllegalArgumentException(Integer.toString(c));
258 }
259
260 // Pass 2: Allocate and fill in char[]
261 final char[] v = new char[n];
262
263 for (int i = offset, j = 0; i < end; i++, j++) {
264 int c = codePoints[i];
265 if (Character.isBmpCodePoint(c))
266 v[j] = (char)c;
267 else
268 Character.toSurrogates(c, v, j++);
269 }
270
271 this.value = v;
272 }
273
274 /**
275 * Allocates a new {@code String} constructed from a subarray of an array
276 * of 8-bit integer values.
277 *
278 * <p> The {@code offset} argument is the index of the first byte of the
279 * subarray, and the {@code count} argument specifies the length of the
280 * subarray.
281 *
282 * <p> Each {@code byte} in the subarray is converted to a {@code char} as
283 * specified in the method above.
284 *
285 * @deprecated This method does not properly convert bytes into characters.
286 * As of JDK 1.1, the preferred way to do this is via the
287 * {@code String} constructors that take a {@link
288 * java.nio.charset.Charset}, charset name, or that use the platform's
289 * default charset.
290 *
291 * @param ascii
292 * The bytes to be converted to characters
293 *
294 * @param hibyte
295 * The top 8 bits of each 16-bit Unicode code unit
296 *
297 * @param offset
298 * The initial offset
299 * @param count
300 * The length
301 *
302 * @throws IndexOutOfBoundsException
303 * If the {@code offset} or {@code count} argument is invalid
304 *
305 * @see #String(byte[], int)
306 * @see #String(byte[], int, int, java.lang.String)
307 * @see #String(byte[], int, int, java.nio.charset.Charset)
308 * @see #String(byte[], int, int)
309 * @see #String(byte[], java.lang.String)
310 * @see #String(byte[], java.nio.charset.Charset)
311 * @see #String(byte[])
312 */
313 @Deprecated
314 public String(byte ascii[], int hibyte, int offset, int count) {
315 checkBounds(ascii, offset, count);
316 char value[] = new char[count];
317
318 if (hibyte == 0) {
319 for (int i = count; i-- > 0;) {
320 value[i] = (char)(ascii[i + offset] & 0xff);
321 }
322 } else {
323 hibyte <<= 8;
324 for (int i = count; i-- > 0;) {
325 value[i] = (char)(hibyte | (ascii[i + offset] & 0xff));
326 }
327 }
328 this.value = value;
329 }
330
331 /**
332 * Allocates a new {@code String} containing characters constructed from
333 * an array of 8-bit integer values. Each character <i>c</i>in the
334 * resulting string is constructed from the corresponding component
335 * <i>b</i> in the byte array such that:
336 *
337 * <blockquote><pre>
338 * <b><i>c</i></b> == (char)(((hibyte & 0xff) << 8)
339 * | (<b><i>b</i></b> & 0xff))
340 * </pre></blockquote>
341 *
342 * @deprecated This method does not properly convert bytes into
343 * characters. As of JDK 1.1, the preferred way to do this is via the
344 * {@code String} constructors that take a {@link
345 * java.nio.charset.Charset}, charset name, or that use the platform's
346 * default charset.
347 *
348 * @param ascii
349 * The bytes to be converted to characters
350 *
351 * @param hibyte
352 * The top 8 bits of each 16-bit Unicode code unit
353 *
354 * @see #String(byte[], int, int, java.lang.String)
355 * @see #String(byte[], int, int, java.nio.charset.Charset)
356 * @see #String(byte[], int, int)
357 * @see #String(byte[], java.lang.String)
358 * @see #String(byte[], java.nio.charset.Charset)
359 * @see #String(byte[])
360 */
361 @Deprecated
362 public String(byte ascii[], int hibyte) {
363 this(ascii, hibyte, 0, ascii.length);
364 }
365
366 /* Common private utility method used to bounds check the byte array
367 * and requested offset & length values used by the String(byte[],..)
368 * constructors.
369 */
370 private static void checkBounds(byte[] bytes, int offset, int length) {
371 if (length < 0)
372 throw new StringIndexOutOfBoundsException(length);
373 if (offset < 0)
374 throw new StringIndexOutOfBoundsException(offset);
375 if (offset > bytes.length - length)
376 throw new StringIndexOutOfBoundsException(offset + length);
377 }
378
379 /**
380 * Constructs a new {@code String} by decoding the specified subarray of
381 * bytes using the specified charset. The length of the new {@code String}
382 * is a function of the charset, and hence may not be equal to the length
383 * of the subarray.
384 *
385 * <p> The behavior of this constructor when the given bytes are not valid
386 * in the given charset is unspecified. The {@link
387 * java.nio.charset.CharsetDecoder} class should be used when more control
388 * over the decoding process is required.
389 *
390 * @param bytes
391 * The bytes to be decoded into characters
392 *
393 * @param offset
394 * The index of the first byte to decode
395 *
396 * @param length
397 * The number of bytes to decode
398
399 * @param charsetName
400 * The name of a supported {@linkplain java.nio.charset.Charset
401 * charset}
402 *
403 * @throws UnsupportedEncodingException
404 * If the named charset is not supported
405 *
406 * @throws IndexOutOfBoundsException
407 * If the {@code offset} and {@code length} arguments index
408 * characters outside the bounds of the {@code bytes} array
409 *
410 * @since JDK1.1
411 */
412 public String(byte bytes[], int offset, int length, String charsetName)
413 throws UnsupportedEncodingException {
414 if (charsetName == null)
415 throw new NullPointerException("charsetName");
416 checkBounds(bytes, offset, length);
417 this.value = StringCoding.decode(charsetName, bytes, offset, length);
418 }
419
420 /**
421 * Constructs a new {@code String} by decoding the specified subarray of
422 * bytes using the specified {@linkplain java.nio.charset.Charset charset}.
423 * The length of the new {@code String} is a function of the charset, and
424 * hence may not be equal to the length of the subarray.
425 *
426 * <p> This method always replaces malformed-input and unmappable-character
427 * sequences with this charset's default replacement string. The {@link
428 * java.nio.charset.CharsetDecoder} class should be used when more control
429 * over the decoding process is required.
430 *
431 * @param bytes
432 * The bytes to be decoded into characters
433 *
434 * @param offset
435 * The index of the first byte to decode
436 *
437 * @param length
438 * The number of bytes to decode
439 *
440 * @param charset
441 * The {@linkplain java.nio.charset.Charset charset} to be used to
442 * decode the {@code bytes}
443 *
444 * @throws IndexOutOfBoundsException
445 * If the {@code offset} and {@code length} arguments index
446 * characters outside the bounds of the {@code bytes} array
447 *
448 * @since 1.6
449 */
450 public String(byte bytes[], int offset, int length, Charset charset) {
451 if (charset == null)
452 throw new NullPointerException("charset");
453 checkBounds(bytes, offset, length);
454 this.value = StringCoding.decode(charset, bytes, offset, length);
455 }
456
457 /**
458 * Constructs a new {@code String} by decoding the specified array of bytes
459 * using the specified {@linkplain java.nio.charset.Charset charset}. The
460 * length of the new {@code String} is a function of the charset, and hence
461 * may not be equal to the length of the byte array.
462 *
463 * <p> The behavior of this constructor when the given bytes are not valid
464 * in the given charset is unspecified. The {@link
465 * java.nio.charset.CharsetDecoder} class should be used when more control
466 * over the decoding process is required.
467 *
468 * @param bytes
469 * The bytes to be decoded into characters
470 *
471 * @param charsetName
472 * The name of a supported {@linkplain java.nio.charset.Charset
473 * charset}
474 *
475 * @throws UnsupportedEncodingException
476 * If the named charset is not supported
477 *
478 * @since JDK1.1
479 */
480 public String(byte bytes[], String charsetName)
481 throws UnsupportedEncodingException {
482 this(bytes, 0, bytes.length, charsetName);
483 }
484
485 /**
486 * Constructs a new {@code String} by decoding the specified array of
487 * bytes using the specified {@linkplain java.nio.charset.Charset charset}.
488 * The length of the new {@code String} is a function of the charset, and
489 * hence may not be equal to the length of the byte array.
490 *
491 * <p> This method always replaces malformed-input and unmappable-character
492 * sequences with this charset's default replacement string. The {@link
493 * java.nio.charset.CharsetDecoder} class should be used when more control
494 * over the decoding process is required.
495 *
496 * @param bytes
497 * The bytes to be decoded into characters
498 *
499 * @param charset
500 * The {@linkplain java.nio.charset.Charset charset} to be used to
501 * decode the {@code bytes}
502 *
503 * @since 1.6
504 */
505 public String(byte bytes[], Charset charset) {
506 this(bytes, 0, bytes.length, charset);
507 }
508
509 /**
510 * Constructs a new {@code String} by decoding the specified subarray of
511 * bytes using the platform's default charset. The length of the new
512 * {@code String} is a function of the charset, and hence may not be equal
513 * to the length of the subarray.
514 *
515 * <p> The behavior of this constructor when the given bytes are not valid
516 * in the default charset is unspecified. The {@link
517 * java.nio.charset.CharsetDecoder} class should be used when more control
518 * over the decoding process is required.
519 *
520 * @param bytes
521 * The bytes to be decoded into characters
522 *
523 * @param offset
524 * The index of the first byte to decode
525 *
526 * @param length
527 * The number of bytes to decode
528 *
529 * @throws IndexOutOfBoundsException
530 * If the {@code offset} and the {@code length} arguments index
531 * characters outside the bounds of the {@code bytes} array
532 *
533 * @since JDK1.1
534 */
535 public String(byte bytes[], int offset, int length) {
536 checkBounds(bytes, offset, length);
537 this.value = StringCoding.decode(bytes, offset, length);
538 }
539
540 /**
541 * Constructs a new {@code String} by decoding the specified array of bytes
542 * using the platform's default charset. The length of the new {@code
543 * String} is a function of the charset, and hence may not be equal to the
544 * length of the byte array.
545 *
546 * <p> The behavior of this constructor when the given bytes are not valid
547 * in the default charset is unspecified. The {@link
548 * java.nio.charset.CharsetDecoder} class should be used when more control
549 * over the decoding process is required.
550 *
551 * @param bytes
552 * The bytes to be decoded into characters
553 *
554 * @since JDK1.1
555 */
556 public String(byte bytes[]) {
557 this(bytes, 0, bytes.length);
558 }
559
560 /**
561 * Allocates a new string that contains the sequence of characters
562 * currently contained in the string buffer argument. The contents of the
563 * string buffer are copied; subsequent modification of the string buffer
564 * does not affect the newly created string.
565 *
566 * @param buffer
567 * A {@code StringBuffer}
568 */
569 public String(StringBuffer buffer) {
570 synchronized(buffer) {
571 this.value = Arrays.copyOf(buffer.getValue(), buffer.length());
572 }
573 }
574
575 /**
576 * Allocates a new string that contains the sequence of characters
577 * currently contained in the string builder argument. The contents of the
578 * string builder are copied; subsequent modification of the string builder
579 * does not affect the newly created string.
580 *
581 * <p> This constructor is provided to ease migration to {@code
582 * StringBuilder}. Obtaining a string from a string builder via the {@code
583 * toString} method is likely to run faster and is generally preferred.
584 *
585 * @param builder
586 * A {@code StringBuilder}
587 *
588 * @since 1.5
589 */
590 public String(StringBuilder builder) {
591 this.value = Arrays.copyOf(builder.getValue(), builder.length());
592 }
593
594 /*
595 * Package private constructor which shares value array for speed.
596 * this constructor is always expected to be called with share==true.
597 * a separate constructor is needed because we already have a public
598 * String(char[]) constructor that makes a copy of the given char[].
599 */
600 String(char[] value, boolean share) {
601 // assert share : "unshared not supported";
602 this.value = value;
603 }
604
605 /**
606 * Returns the length of this string.
607 * The length is equal to the number of <a href="Character.html#unicode">Unicode
608 * code units</a> in the string.
609 *
610 * @return the length of the sequence of characters represented by this
611 * object.
612 */
613 public int length() {
614 return value.length;
615 }
616
617 /**
618 * Returns <tt>true</tt> if, and only if, {@link #length()} is <tt>0</tt>.
619 *
620 * @return <tt>true</tt> if {@link #length()} is <tt>0</tt>, otherwise
621 * <tt>false</tt>
622 *
623 * @since 1.6
624 */
625 public boolean isEmpty() {
626 return value.length == 0;
627 }
628
629 /**
630 * Returns the {@code char} value at the
631 * specified index. An index ranges from {@code 0} to
632 * {@code length() - 1}. The first {@code char} value of the sequence
633 * is at index {@code 0}, the next at index {@code 1},
634 * and so on, as for array indexing.
635 *
636 * <p>If the {@code char} value specified by the index is a
637 * <a href="Character.html#unicode">surrogate</a>, the surrogate
638 * value is returned.
639 *
640 * @param index the index of the {@code char} value.
641 * @return the {@code char} value at the specified index of this string.
642 * The first {@code char} value is at index {@code 0}.
643 * @exception IndexOutOfBoundsException if the {@code index}
644 * argument is negative or not less than the length of this
645 * string.
646 */
647 public char charAt(int index) {
648 if ((index < 0) || (index >= value.length)) {
649 throw new StringIndexOutOfBoundsException(index);
650 }
651 return value[index];
652 }
653
654 /**
655 * Returns the character (Unicode code point) at the specified
656 * index. The index refers to {@code char} values
657 * (Unicode code units) and ranges from {@code 0} to
658 * {@link #length()}{@code - 1}.
659 *
660 * <p> If the {@code char} value specified at the given index
661 * is in the high-surrogate range, the following index is less
662 * than the length of this {@code String}, and the
663 * {@code char} value at the following index is in the
664 * low-surrogate range, then the supplementary code point
665 * corresponding to this surrogate pair is returned. Otherwise,
666 * the {@code char} value at the given index is returned.
667 *
668 * @param index the index to the {@code char} values
669 * @return the code point value of the character at the
670 * {@code index}
671 * @exception IndexOutOfBoundsException if the {@code index}
672 * argument is negative or not less than the length of this
673 * string.
674 * @since 1.5
675 */
676 public int codePointAt(int index) {
677 if ((index < 0) || (index >= value.length)) {
678 throw new StringIndexOutOfBoundsException(index);
679 }
680 return Character.codePointAtImpl(value, index, value.length);
681 }
682
683 /**
684 * Returns the character (Unicode code point) before the specified
685 * index. The index refers to {@code char} values
686 * (Unicode code units) and ranges from {@code 1} to {@link
687 * CharSequence#length() length}.
688 *
689 * <p> If the {@code char} value at {@code (index - 1)}
690 * is in the low-surrogate range, {@code (index - 2)} is not
691 * negative, and the {@code char} value at {@code (index -
692 * 2)} is in the high-surrogate range, then the
693 * supplementary code point value of the surrogate pair is
694 * returned. If the {@code char} value at {@code index -
695 * 1} is an unpaired low-surrogate or a high-surrogate, the
696 * surrogate value is returned.
697 *
698 * @param index the index following the code point that should be returned
699 * @return the Unicode code point value before the given index.
700 * @exception IndexOutOfBoundsException if the {@code index}
701 * argument is less than 1 or greater than the length
702 * of this string.
703 * @since 1.5
704 */
705 public int codePointBefore(int index) {
706 int i = index - 1;
707 if ((i < 0) || (i >= value.length)) {
708 throw new StringIndexOutOfBoundsException(index);
709 }
710 return Character.codePointBeforeImpl(value, index, 0);
711 }
712
713 /**
714 * Returns the number of Unicode code points in the specified text
715 * range of this {@code String}. The text range begins at the
716 * specified {@code beginIndex} and extends to the
717 * {@code char} at index {@code endIndex - 1}. Thus the
718 * length (in {@code char}s) of the text range is
719 * {@code endIndex-beginIndex}. Unpaired surrogates within
720 * the text range count as one code point each.
721 *
722 * @param beginIndex the index to the first {@code char} of
723 * the text range.
724 * @param endIndex the index after the last {@code char} of
725 * the text range.
726 * @return the number of Unicode code points in the specified text
727 * range
728 * @exception IndexOutOfBoundsException if the
729 * {@code beginIndex} is negative, or {@code endIndex}
730 * is larger than the length of this {@code String}, or
731 * {@code beginIndex} is larger than {@code endIndex}.
732 * @since 1.5
733 */
734 public int codePointCount(int beginIndex, int endIndex) {
735 if (beginIndex < 0 || endIndex > value.length || beginIndex > endIndex) {
736 throw new IndexOutOfBoundsException();
737 }
738 return Character.codePointCountImpl(value, beginIndex, endIndex - beginIndex);
739 }
740
741 /**
742 * Returns the index within this {@code String} that is
743 * offset from the given {@code index} by
744 * {@code codePointOffset} code points. Unpaired surrogates
745 * within the text range given by {@code index} and
746 * {@code codePointOffset} count as one code point each.
747 *
748 * @param index the index to be offset
749 * @param codePointOffset the offset in code points
750 * @return the index within this {@code String}
751 * @exception IndexOutOfBoundsException if {@code index}
752 * is negative or larger then the length of this
753 * {@code String}, or if {@code codePointOffset} is positive
754 * and the substring starting with {@code index} has fewer
755 * than {@code codePointOffset} code points,
756 * or if {@code codePointOffset} is negative and the substring
757 * before {@code index} has fewer than the absolute value
758 * of {@code codePointOffset} code points.
759 * @since 1.5
760 */
761 public int offsetByCodePoints(int index, int codePointOffset) {
762 if (index < 0 || index > value.length) {
763 throw new IndexOutOfBoundsException();
764 }
765 return Character.offsetByCodePointsImpl(value, 0, value.length,
766 index, codePointOffset);
767 }
768
769 /**
770 * Copy characters from this string into dst starting at dstBegin.
771 * This method doesn't perform any range checking.
772 */
773 void getChars(char dst[], int dstBegin) {
774 System.arraycopy(value, 0, dst, dstBegin, value.length);
775 }
776
777 /**
778 * Copies characters from this string into the destination character
779 * array.
780 * <p>
781 * The first character to be copied is at index {@code srcBegin};
782 * the last character to be copied is at index {@code srcEnd-1}
783 * (thus the total number of characters to be copied is
784 * {@code srcEnd-srcBegin}). The characters are copied into the
785 * subarray of {@code dst} starting at index {@code dstBegin}
786 * and ending at index:
787 * <p><blockquote><pre>
788 * dstbegin + (srcEnd-srcBegin) - 1
789 * </pre></blockquote>
790 *
791 * @param srcBegin index of the first character in the string
792 * to copy.
793 * @param srcEnd index after the last character in the string
794 * to copy.
795 * @param dst the destination array.
796 * @param dstBegin the start offset in the destination array.
797 * @exception IndexOutOfBoundsException If any of the following
798 * is true:
799 * <ul><li>{@code srcBegin} is negative.
800 * <li>{@code srcBegin} is greater than {@code srcEnd}
801 * <li>{@code srcEnd} is greater than the length of this
802 * string
803 * <li>{@code dstBegin} is negative
804 * <li>{@code dstBegin+(srcEnd-srcBegin)} is larger than
805 * {@code dst.length}</ul>
806 */
807 public void getChars(int srcBegin, int srcEnd, char dst[], int dstBegin) {
808 if (srcBegin < 0) {
809 throw new StringIndexOutOfBoundsException(srcBegin);
810 }
811 if (srcEnd > value.length) {
812 throw new StringIndexOutOfBoundsException(srcEnd);
813 }
814 if (srcBegin > srcEnd) {
815 throw new StringIndexOutOfBoundsException(srcEnd - srcBegin);
816 }
817 System.arraycopy(value, srcBegin, dst, dstBegin, srcEnd - srcBegin);
818 }
819
820 /**
821 * Copies characters from this string into the destination byte array. Each
822 * byte receives the 8 low-order bits of the corresponding character. The
823 * eight high-order bits of each character are not copied and do not
824 * participate in the transfer in any way.
825 *
826 * <p> The first character to be copied is at index {@code srcBegin}; the
827 * last character to be copied is at index {@code srcEnd-1}. The total
828 * number of characters to be copied is {@code srcEnd-srcBegin}. The
829 * characters, converted to bytes, are copied into the subarray of {@code
830 * dst} starting at index {@code dstBegin} and ending at index:
831 *
832 * <blockquote><pre>
833 * dstbegin + (srcEnd-srcBegin) - 1
834 * </pre></blockquote>
835 *
836 * @deprecated This method does not properly convert characters into
837 * bytes. As of JDK 1.1, the preferred way to do this is via the
838 * {@link #getBytes()} method, which uses the platform's default charset.
839 *
840 * @param srcBegin
841 * Index of the first character in the string to copy
842 *
843 * @param srcEnd
844 * Index after the last character in the string to copy
845 *
846 * @param dst
847 * The destination array
848 *
849 * @param dstBegin
850 * The start offset in the destination array
851 *
852 * @throws IndexOutOfBoundsException
853 * If any of the following is true:
854 * <ul>
855 * <li> {@code srcBegin} is negative
856 * <li> {@code srcBegin} is greater than {@code srcEnd}
857 * <li> {@code srcEnd} is greater than the length of this String
858 * <li> {@code dstBegin} is negative
859 * <li> {@code dstBegin+(srcEnd-srcBegin)} is larger than {@code
860 * dst.length}
861 * </ul>
862 */
863 @Deprecated
864 public void getBytes(int srcBegin, int srcEnd, byte dst[], int dstBegin) {
865 if (srcBegin < 0) {
866 throw new StringIndexOutOfBoundsException(srcBegin);
867 }
868 if (srcEnd > value.length) {
869 throw new StringIndexOutOfBoundsException(srcEnd);
870 }
871 if (srcBegin > srcEnd) {
872 throw new StringIndexOutOfBoundsException(srcEnd - srcBegin);
873 }
874 int j = dstBegin;
875 int n = srcEnd;
876 int i = srcBegin;
877 char[] val = value; /* avoid getfield opcode */
878
879 while (i < n) {
880 dst[j++] = (byte)val[i++];
881 }
882 }
883
884 /**
885 * Encodes this {@code String} into a sequence of bytes using the named
886 * charset, storing the result into a new byte array.
887 *
888 * <p> The behavior of this method when this string cannot be encoded in
889 * the given charset is unspecified. The {@link
890 * java.nio.charset.CharsetEncoder} class should be used when more control
891 * over the encoding process is required.
892 *
893 * @param charsetName
894 * The name of a supported {@linkplain java.nio.charset.Charset
895 * charset}
896 *
897 * @return The resultant byte array
898 *
899 * @throws UnsupportedEncodingException
900 * If the named charset is not supported
901 *
902 * @since JDK1.1
903 */
904 public byte[] getBytes(String charsetName)
905 throws UnsupportedEncodingException {
906 if (charsetName == null) throw new NullPointerException();
907 return StringCoding.encode(charsetName, value, 0, value.length);
908 }
909
910 /**
911 * Encodes this {@code String} into a sequence of bytes using the given
912 * {@linkplain java.nio.charset.Charset charset}, storing the result into a
913 * new byte array.
914 *
915 * <p> This method always replaces malformed-input and unmappable-character
916 * sequences with this charset's default replacement byte array. The
917 * {@link java.nio.charset.CharsetEncoder} class should be used when more
918 * control over the encoding process is required.
919 *
920 * @param charset
921 * The {@linkplain java.nio.charset.Charset} to be used to encode
922 * the {@code String}
923 *
924 * @return The resultant byte array
925 *
926 * @since 1.6
927 */
928 public byte[] getBytes(Charset charset) {
929 if (charset == null) throw new NullPointerException();
930 return StringCoding.encode(charset, value, 0, value.length);
931 }
932
933 /**
934 * Encodes this {@code String} into a sequence of bytes using the
935 * platform's default charset, storing the result into a new byte array.
936 *
937 * <p> The behavior of this method when this string cannot be encoded in
938 * the default charset is unspecified. The {@link
939 * java.nio.charset.CharsetEncoder} class should be used when more control
940 * over the encoding process is required.
941 *
942 * @return The resultant byte array
943 *
944 * @since JDK1.1
945 */
946 public byte[] getBytes() {
947 return StringCoding.encode(value, 0, value.length);
948 }
949
950 /**
951 * Compares this string to the specified object. The result is {@code
952 * true} if and only if the argument is not {@code null} and is a {@code
953 * String} object that represents the same sequence of characters as this
954 * object.
955 *
956 * @param anObject
957 * The object to compare this {@code String} against
958 *
959 * @return {@code true} if the given object represents a {@code String}
960 * equivalent to this string, {@code false} otherwise
961 *
962 * @see #compareTo(String)
963 * @see #equalsIgnoreCase(String)
964 */
965 public boolean equals(Object anObject) {
966 if (this == anObject) {
967 return true;
968 }
969 if (anObject instanceof String) {
970 String anotherString = (String) anObject;
971 int n = value.length;
972 if (n == anotherString.value.length) {
973 char v1[] = value;
974 char v2[] = anotherString.value;
975 int i = 0;
976 while (n-- != 0) {
977 if (v1[i] != v2[i])
978 return false;
979 i++;
980 }
981 return true;
982 }
983 }
984 return false;
985 }
986
987 /**
988 * Compares this string to the specified {@code StringBuffer}. The result
989 * is {@code true} if and only if this {@code String} represents the same
990 * sequence of characters as the specified {@code StringBuffer}.
991 *
992 * @param sb
993 * The {@code StringBuffer} to compare this {@code String} against
994 *
995 * @return {@code true} if this {@code String} represents the same
996 * sequence of characters as the specified {@code StringBuffer},
997 * {@code false} otherwise
998 *
999 * @since 1.4
1000 */
1001 public boolean contentEquals(StringBuffer sb) {
1002 synchronized (sb) {
1003 return contentEquals((CharSequence) sb);
1004 }
1005 }
1006
1007 /**
1008 * Compares this string to the specified {@code CharSequence}. The result
1009 * is {@code true} if and only if this {@code String} represents the same
1010 * sequence of char values as the specified sequence.
1011 *
1012 * @param cs
1013 * The sequence to compare this {@code String} against
1014 *
1015 * @return {@code true} if this {@code String} represents the same
1016 * sequence of char values as the specified sequence, {@code
1017 * false} otherwise
1018 *
1019 * @since 1.5
1020 */
1021 public boolean contentEquals(CharSequence cs) {
1022 if (value.length != cs.length())
1023 return false;
1024 // Argument is a StringBuffer, StringBuilder
1025 if (cs instanceof AbstractStringBuilder) {
1026 char v1[] = value;
1027 char v2[] = ((AbstractStringBuilder) cs).getValue();
1028 int i = 0;
1029 int n = value.length;
1030 while (n-- != 0) {
1031 if (v1[i] != v2[i])
1032 return false;
1033 i++;
1034 }
1035 return true;
1036 }
1037 // Argument is a String
1038 if (cs.equals(this))
1039 return true;
1040 // Argument is a generic CharSequence
1041 char v1[] = value;
1042 int i = 0;
1043 int n = value.length;
1044 while (n-- != 0) {
1045 if (v1[i] != cs.charAt(i))
1046 return false;
1047 i++;
1048 }
1049 return true;
1050 }
1051
1052 /**
1053 * Compares this {@code String} to another {@code String}, ignoring case
1054 * considerations. Two strings are considered equal ignoring case if they
1055 * are of the same length and corresponding characters in the two strings
1056 * are equal ignoring case.
1057 *
1058 * <p> Two characters {@code c1} and {@code c2} are considered the same
1059 * ignoring case if at least one of the following is true:
1060 * <ul>
1061 * <li> The two characters are the same (as compared by the
1062 * {@code ==} operator)
1063 * <li> Applying the method {@link
1064 * java.lang.Character#toUpperCase(char)} to each character
1065 * produces the same result
1066 * <li> Applying the method {@link
1067 * java.lang.Character#toLowerCase(char)} to each character
1068 * produces the same result
1069 * </ul>
1070 *
1071 * @param anotherString
1072 * The {@code String} to compare this {@code String} against
1073 *
1074 * @return {@code true} if the argument is not {@code null} and it
1075 * represents an equivalent {@code String} ignoring case; {@code
1076 * false} otherwise
1077 *
1078 * @see #equals(Object)
1079 */
1080 public boolean equalsIgnoreCase(String anotherString) {
1081 return (this == anotherString) ? true
1082 : (anotherString != null)
1083 && (anotherString.value.length == value.length)
1084 && regionMatches(true, 0, anotherString, 0, value.length);
1085 }
1086
1087 /**
1088 * Compares two strings lexicographically.
1089 * The comparison is based on the Unicode value of each character in
1090 * the strings. The character sequence represented by this
1091 * {@code String} object is compared lexicographically to the
1092 * character sequence represented by the argument string. The result is
1093 * a negative integer if this {@code String} object
1094 * lexicographically precedes the argument string. The result is a
1095 * positive integer if this {@code String} object lexicographically
1096 * follows the argument string. The result is zero if the strings
1097 * are equal; {@code compareTo} returns {@code 0} exactly when
1098 * the {@link #equals(Object)} method would return {@code true}.
1099 * <p>
1100 * This is the definition of lexicographic ordering. If two strings are
1101 * different, then either they have different characters at some index
1102 * that is a valid index for both strings, or their lengths are different,
1103 * or both. If they have different characters at one or more index
1104 * positions, let <i>k</i> be the smallest such index; then the string
1105 * whose character at position <i>k</i> has the smaller value, as
1106 * determined by using the < operator, lexicographically precedes the
1107 * other string. In this case, {@code compareTo} returns the
1108 * difference of the two character values at position {@code k} in
1109 * the two string -- that is, the value:
1110 * <blockquote><pre>
1111 * this.charAt(k)-anotherString.charAt(k)
1112 * </pre></blockquote>
1113 * If there is no index position at which they differ, then the shorter
1114 * string lexicographically precedes the longer string. In this case,
1115 * {@code compareTo} returns the difference of the lengths of the
1116 * strings -- that is, the value:
1117 * <blockquote><pre>
1118 * this.length()-anotherString.length()
1119 * </pre></blockquote>
1120 *
1121 * @param anotherString the {@code String} to be compared.
1122 * @return the value {@code 0} if the argument string is equal to
1123 * this string; a value less than {@code 0} if this string
1124 * is lexicographically less than the string argument; and a
1125 * value greater than {@code 0} if this string is
1126 * lexicographically greater than the string argument.
1127 */
1128 public int compareTo(String anotherString) {
1129 int len1 = value.length;
1130 int len2 = anotherString.value.length;
1131 int lim = Math.min(len1, len2);
1132 char v1[] = value;
1133 char v2[] = anotherString.value;
1134
1135 int k = 0;
1136 while (k < lim) {
1137 char c1 = v1[k];
1138 char c2 = v2[k];
1139 if (c1 != c2) {
1140 return c1 - c2;
1141 }
1142 k++;
1143 }
1144 return len1 - len2;
1145 }
1146
1147 /**
1148 * A Comparator that orders {@code String} objects as by
1149 * {@code compareToIgnoreCase}. This comparator is serializable.
1150 * <p>
1151 * Note that this Comparator does <em>not</em> take locale into account,
1152 * and will result in an unsatisfactory ordering for certain locales.
1153 * The java.text package provides <em>Collators</em> to allow
1154 * locale-sensitive ordering.
1155 *
1156 * @see java.text.Collator#compare(String, String)
1157 * @since 1.2
1158 */
1159 public static final Comparator<String> CASE_INSENSITIVE_ORDER
1160 = new CaseInsensitiveComparator();
1161 private static class CaseInsensitiveComparator
1162 implements Comparator<String>, java.io.Serializable {
1163 // use serialVersionUID from JDK 1.2.2 for interoperability
1164 private static final long serialVersionUID = 8575799808933029326L;
1165
1166 public int compare(String s1, String s2) {
1167 int n1 = s1.length();
1168 int n2 = s2.length();
1169 int min = Math.min(n1, n2);
1170 for (int i = 0; i < min; i++) {
1171 char c1 = s1.charAt(i);
1172 char c2 = s2.charAt(i);
1173 if (c1 != c2) {
1174 c1 = Character.toUpperCase(c1);
1175 c2 = Character.toUpperCase(c2);
1176 if (c1 != c2) {
1177 c1 = Character.toLowerCase(c1);
1178 c2 = Character.toLowerCase(c2);
1179 if (c1 != c2) {
1180 // No overflow because of numeric promotion
1181 return c1 - c2;
1182 }
1183 }
1184 }
1185 }
1186 return n1 - n2;
1187 }
1188
1189 /** Replaces the de-serialized object. */
1190 private Object readResolve() { return CASE_INSENSITIVE_ORDER; }
1191 }
1192
1193 /**
1194 * Compares two strings lexicographically, ignoring case
1195 * differences. This method returns an integer whose sign is that of
1196 * calling {@code compareTo} with normalized versions of the strings
1197 * where case differences have been eliminated by calling
1198 * {@code Character.toLowerCase(Character.toUpperCase(character))} on
1199 * each character.
1200 * <p>
1201 * Note that this method does <em>not</em> take locale into account,
1202 * and will result in an unsatisfactory ordering for certain locales.
1203 * The java.text package provides <em>collators</em> to allow
1204 * locale-sensitive ordering.
1205 *
1206 * @param str the {@code String} to be compared.
1207 * @return a negative integer, zero, or a positive integer as the
1208 * specified String is greater than, equal to, or less
1209 * than this String, ignoring case considerations.
1210 * @see java.text.Collator#compare(String, String)
1211 * @since 1.2
1212 */
1213 public int compareToIgnoreCase(String str) {
1214 return CASE_INSENSITIVE_ORDER.compare(this, str);
1215 }
1216
1217 /**
1218 * Tests if two string regions are equal.
1219 * <p>
1220 * A substring of this <tt>String</tt> object is compared to a substring
1221 * of the argument other. The result is true if these substrings
1222 * represent identical character sequences. The substring of this
1223 * <tt>String</tt> object to be compared begins at index <tt>toffset</tt>
1224 * and has length <tt>len</tt>. The substring of other to be compared
1225 * begins at index <tt>ooffset</tt> and has length <tt>len</tt>. The
1226 * result is <tt>false</tt> if and only if at least one of the following
1227 * is true:
1228 * <ul><li><tt>toffset</tt> is negative.
1229 * <li><tt>ooffset</tt> is negative.
1230 * <li><tt>toffset+len</tt> is greater than the length of this
1231 * <tt>String</tt> object.
1232 * <li><tt>ooffset+len</tt> is greater than the length of the other
1233 * argument.
1234 * <li>There is some nonnegative integer <i>k</i> less than <tt>len</tt>
1235 * such that:
1236 * <tt>this.charAt(toffset+<i>k</i>) != other.charAt(ooffset+<i>k</i>)</tt>
1237 * </ul>
1238 *
1239 * @param toffset the starting offset of the subregion in this string.
1240 * @param other the string argument.
1241 * @param ooffset the starting offset of the subregion in the string
1242 * argument.
1243 * @param len the number of characters to compare.
1244 * @return {@code true} if the specified subregion of this string
1245 * exactly matches the specified subregion of the string argument;
1246 * {@code false} otherwise.
1247 */
1248 public boolean regionMatches(int toffset, String other, int ooffset,
1249 int len) {
1250 char ta[] = value;
1251 int to = toffset;
1252 char pa[] = other.value;
1253 int po = ooffset;
1254 // Note: toffset, ooffset, or len might be near -1>>>1.
1255 if ((ooffset < 0) || (toffset < 0)
1256 || (toffset > (long)value.length - len)
1257 || (ooffset > (long)other.value.length - len)) {
1258 return false;
1259 }
1260 while (len-- > 0) {
1261 if (ta[to++] != pa[po++]) {
1262 return false;
1263 }
1264 }
1265 return true;
1266 }
1267
1268 /**
1269 * Tests if two string regions are equal.
1270 * <p>
1271 * A substring of this <tt>String</tt> object is compared to a substring
1272 * of the argument <tt>other</tt>. The result is <tt>true</tt> if these
1273 * substrings represent character sequences that are the same, ignoring
1274 * case if and only if <tt>ignoreCase</tt> is true. The substring of
1275 * this <tt>String</tt> object to be compared begins at index
1276 * <tt>toffset</tt> and has length <tt>len</tt>. The substring of
1277 * <tt>other</tt> to be compared begins at index <tt>ooffset</tt> and
1278 * has length <tt>len</tt>. The result is <tt>false</tt> if and only if
1279 * at least one of the following is true:
1280 * <ul><li><tt>toffset</tt> is negative.
1281 * <li><tt>ooffset</tt> is negative.
1282 * <li><tt>toffset+len</tt> is greater than the length of this
1283 * <tt>String</tt> object.
1284 * <li><tt>ooffset+len</tt> is greater than the length of the other
1285 * argument.
1286 * <li><tt>ignoreCase</tt> is <tt>false</tt> and there is some nonnegative
1287 * integer <i>k</i> less than <tt>len</tt> such that:
1288 * <blockquote><pre>
1289 * this.charAt(toffset+k) != other.charAt(ooffset+k)
1290 * </pre></blockquote>
1291 * <li><tt>ignoreCase</tt> is <tt>true</tt> and there is some nonnegative
1292 * integer <i>k</i> less than <tt>len</tt> such that:
1293 * <blockquote><pre>
1294 * Character.toLowerCase(this.charAt(toffset+k)) !=
1295 Character.toLowerCase(other.charAt(ooffset+k))
1296 * </pre></blockquote>
1297 * and:
1298 * <blockquote><pre>
1299 * Character.toUpperCase(this.charAt(toffset+k)) !=
1300 * Character.toUpperCase(other.charAt(ooffset+k))
1301 * </pre></blockquote>
1302 * </ul>
1303 *
1304 * @param ignoreCase if {@code true}, ignore case when comparing
1305 * characters.
1306 * @param toffset the starting offset of the subregion in this
1307 * string.
1308 * @param other the string argument.
1309 * @param ooffset the starting offset of the subregion in the string
1310 * argument.
1311 * @param len the number of characters to compare.
1312 * @return {@code true} if the specified subregion of this string
1313 * matches the specified subregion of the string argument;
1314 * {@code false} otherwise. Whether the matching is exact
1315 * or case insensitive depends on the {@code ignoreCase}
1316 * argument.
1317 */
1318 public boolean regionMatches(boolean ignoreCase, int toffset,
1319 String other, int ooffset, int len) {
1320 char ta[] = value;
1321 int to = toffset;
1322 char pa[] = other.value;
1323 int po = ooffset;
1324 // Note: toffset, ooffset, or len might be near -1>>>1.
1325 if ((ooffset < 0) || (toffset < 0)
1326 || (toffset > (long)value.length - len)
1327 || (ooffset > (long)other.value.length - len)) {
1328 return false;
1329 }
1330 while (len-- > 0) {
1331 char c1 = ta[to++];
1332 char c2 = pa[po++];
1333 if (c1 == c2) {
1334 continue;
1335 }
1336 if (ignoreCase) {
1337 // If characters don't match but case may be ignored,
1338 // try converting both characters to uppercase.
1339 // If the results match, then the comparison scan should
1340 // continue.
1341 char u1 = Character.toUpperCase(c1);
1342 char u2 = Character.toUpperCase(c2);
1343 if (u1 == u2) {
1344 continue;
1345 }
1346 // Unfortunately, conversion to uppercase does not work properly
1347 // for the Georgian alphabet, which has strange rules about case
1348 // conversion. So we need to make one last check before
1349 // exiting.
1350 if (Character.toLowerCase(u1) == Character.toLowerCase(u2)) {
1351 continue;
1352 }
1353 }
1354 return false;
1355 }
1356 return true;
1357 }
1358
1359 /**
1360 * Tests if the substring of this string beginning at the
1361 * specified index starts with the specified prefix.
1362 *
1363 * @param prefix the prefix.
1364 * @param toffset where to begin looking in this string.
1365 * @return {@code true} if the character sequence represented by the
1366 * argument is a prefix of the substring of this object starting
1367 * at index {@code toffset}; {@code false} otherwise.
1368 * The result is {@code false} if {@code toffset} is
1369 * negative or greater than the length of this
1370 * {@code String} object; otherwise the result is the same
1371 * as the result of the expression
1372 * <pre>
1373 * this.substring(toffset).startsWith(prefix)
1374 * </pre>
1375 */
1376 public boolean startsWith(String prefix, int toffset) {
1377 char ta[] = value;
1378 int to = toffset;
1379 char pa[] = prefix.value;
1380 int po = 0;
1381 int pc = prefix.value.length;
1382 // Note: toffset might be near -1>>>1.
1383 if ((toffset < 0) || (toffset > value.length - pc)) {
1384 return false;
1385 }
1386 while (--pc >= 0) {
1387 if (ta[to++] != pa[po++]) {
1388 return false;
1389 }
1390 }
1391 return true;
1392 }
1393
1394 /**
1395 * Tests if this string starts with the specified prefix.
1396 *
1397 * @param prefix the prefix.
1398 * @return {@code true} if the character sequence represented by the
1399 * argument is a prefix of the character sequence represented by
1400 * this string; {@code false} otherwise.
1401 * Note also that {@code true} will be returned if the
1402 * argument is an empty string or is equal to this
1403 * {@code String} object as determined by the
1404 * {@link #equals(Object)} method.
1405 * @since 1. 0
1406 */
1407 public boolean startsWith(String prefix) {
1408 return startsWith(prefix, 0);
1409 }
1410
1411 /**
1412 * Tests if this string ends with the specified suffix.
1413 *
1414 * @param suffix the suffix.
1415 * @return {@code true} if the character sequence represented by the
1416 * argument is a suffix of the character sequence represented by
1417 * this object; {@code false} otherwise. Note that the
1418 * result will be {@code true} if the argument is the
1419 * empty string or is equal to this {@code String} object
1420 * as determined by the {@link #equals(Object)} method.
1421 */
1422 public boolean endsWith(String suffix) {
1423 return startsWith(suffix, value.length - suffix.value.length);
1424 }
1425
1426 /**
1427 * Returns a hash code for this string. The hash code for a
1428 * {@code String} object is computed as
1429 * <blockquote><pre>
1430 * s[0]*31^(n-1) + s[1]*31^(n-2) + ... + s[n-1]
1431 * </pre></blockquote>
1432 * using {@code int} arithmetic, where {@code s[i]} is the
1433 * <i>i</i>th character of the string, {@code n} is the length of
1434 * the string, and {@code ^} indicates exponentiation.
1435 * (The hash value of the empty string is zero.)
1436 *
1437 * @return a hash code value for this object.
1438 */
1439 public int hashCode() {
1440 int h = hash;
1441 if (h == 0 && value.length > 0) {
1442 char val[] = value;
1443
1444 for (int i = 0; i < value.length; i++) {
1445 h = 31 * h + val[i];
1446 }
1447 hash = h;
1448 }
1449 return h;
1450 }
1451
1452 /**
1453 * Returns the index within this string of the first occurrence of
1454 * the specified character. If a character with value
1455 * {@code ch} occurs in the character sequence represented by
1456 * this {@code String} object, then the index (in Unicode
1457 * code units) of the first such occurrence is returned. For
1458 * values of {@code ch} in the range from 0 to 0xFFFF
1459 * (inclusive), this is the smallest value <i>k</i> such that:
1460 * <blockquote><pre>
1461 * this.charAt(<i>k</i>) == ch
1462 * </pre></blockquote>
1463 * is true. For other values of {@code ch}, it is the
1464 * smallest value <i>k</i> such that:
1465 * <blockquote><pre>
1466 * this.codePointAt(<i>k</i>) == ch
1467 * </pre></blockquote>
1468 * is true. In either case, if no such character occurs in this
1469 * string, then {@code -1} is returned.
1470 *
1471 * @param ch a character (Unicode code point).
1472 * @return the index of the first occurrence of the character in the
1473 * character sequence represented by this object, or
1474 * {@code -1} if the character does not occur.
1475 */
1476 public int indexOf(int ch) {
1477 return indexOf(ch, 0);
1478 }
1479
1480 /**
1481 * Returns the index within this string of the first occurrence of the
1482 * specified character, starting the search at the specified index.
1483 * <p>
1484 * If a character with value {@code ch} occurs in the
1485 * character sequence represented by this {@code String}
1486 * object at an index no smaller than {@code fromIndex}, then
1487 * the index of the first such occurrence is returned. For values
1488 * of {@code ch} in the range from 0 to 0xFFFF (inclusive),
1489 * this is the smallest value <i>k</i> such that:
1490 * <blockquote><pre>
1491 * (this.charAt(<i>k</i>) == ch) && (<i>k</i> >= fromIndex)
1492 * </pre></blockquote>
1493 * is true. For other values of {@code ch}, it is the
1494 * smallest value <i>k</i> such that:
1495 * <blockquote><pre>
1496 * (this.codePointAt(<i>k</i>) == ch) && (<i>k</i> >= fromIndex)
1497 * </pre></blockquote>
1498 * is true. In either case, if no such character occurs in this
1499 * string at or after position {@code fromIndex}, then
1500 * {@code -1} is returned.
1501 *
1502 * <p>
1503 * There is no restriction on the value of {@code fromIndex}. If it
1504 * is negative, it has the same effect as if it were zero: this entire
1505 * string may be searched. If it is greater than the length of this
1506 * string, it has the same effect as if it were equal to the length of
1507 * this string: {@code -1} is returned.
1508 *
1509 * <p>All indices are specified in {@code char} values
1510 * (Unicode code units).
1511 *
1512 * @param ch a character (Unicode code point).
1513 * @param fromIndex the index to start the search from.
1514 * @return the index of the first occurrence of the character in the
1515 * character sequence represented by this object that is greater
1516 * than or equal to {@code fromIndex}, or {@code -1}
1517 * if the character does not occur.
1518 */
1519 public int indexOf(int ch, int fromIndex) {
1520 final int max = value.length;
1521 if (fromIndex < 0) {
1522 fromIndex = 0;
1523 } else if (fromIndex >= max) {
1524 // Note: fromIndex might be near -1>>>1.
1525 return -1;
1526 }
1527
1528 if (ch < Character.MIN_SUPPLEMENTARY_CODE_POINT) {
1529 // handle most cases here (ch is a BMP code point or a
1530 // negative value (invalid code point))
1531 final char[] value = this.value;
1532 for (int i = fromIndex; i < max; i++) {
1533 if (value[i] == ch) {
1534 return i;
1535 }
1536 }
1537 return -1;
1538 } else {
1539 return indexOfSupplementary(ch, fromIndex);
1540 }
1541 }
1542
1543 /**
1544 * Handles (rare) calls of indexOf with a supplementary character.
1545 */
1546 private int indexOfSupplementary(int ch, int fromIndex) {
1547 if (Character.isValidCodePoint(ch)) {
1548 final char[] value = this.value;
1549 final char hi = Character.highSurrogate(ch);
1550 final char lo = Character.lowSurrogate(ch);
1551 final int max = value.length - 1;
1552 for (int i = fromIndex; i < max; i++) {
1553 if (value[i] == hi && value[i + 1] == lo) {
1554 return i;
1555 }
1556 }
1557 }
1558 return -1;
1559 }
1560
1561 /**
1562 * Returns the index within this string of the last occurrence of
1563 * the specified character. For values of {@code ch} in the
1564 * range from 0 to 0xFFFF (inclusive), the index (in Unicode code
1565 * units) returned is the largest value <i>k</i> such that:
1566 * <blockquote><pre>
1567 * this.charAt(<i>k</i>) == ch
1568 * </pre></blockquote>
1569 * is true. For other values of {@code ch}, it is the
1570 * largest value <i>k</i> such that:
1571 * <blockquote><pre>
1572 * this.codePointAt(<i>k</i>) == ch
1573 * </pre></blockquote>
1574 * is true. In either case, if no such character occurs in this
1575 * string, then {@code -1} is returned. The
1576 * {@code String} is searched backwards starting at the last
1577 * character.
1578 *
1579 * @param ch a character (Unicode code point).
1580 * @return the index of the last occurrence of the character in the
1581 * character sequence represented by this object, or
1582 * {@code -1} if the character does not occur.
1583 */
1584 public int lastIndexOf(int ch) {
1585 return lastIndexOf(ch, value.length - 1);
1586 }
1587
1588 /**
1589 * Returns the index within this string of the last occurrence of
1590 * the specified character, searching backward starting at the
1591 * specified index. For values of {@code ch} in the range
1592 * from 0 to 0xFFFF (inclusive), the index returned is the largest
1593 * value <i>k</i> such that:
1594 * <blockquote><pre>
1595 * (this.charAt(<i>k</i>) == ch) && (<i>k</i> <= fromIndex)
1596 * </pre></blockquote>
1597 * is true. For other values of {@code ch}, it is the
1598 * largest value <i>k</i> such that:
1599 * <blockquote><pre>
1600 * (this.codePointAt(<i>k</i>) == ch) && (<i>k</i> <= fromIndex)
1601 * </pre></blockquote>
1602 * is true. In either case, if no such character occurs in this
1603 * string at or before position {@code fromIndex}, then
1604 * {@code -1} is returned.
1605 *
1606 * <p>All indices are specified in {@code char} values
1607 * (Unicode code units).
1608 *
1609 * @param ch a character (Unicode code point).
1610 * @param fromIndex the index to start the search from. There is no
1611 * restriction on the value of {@code fromIndex}. If it is
1612 * greater than or equal to the length of this string, it has
1613 * the same effect as if it were equal to one less than the
1614 * length of this string: this entire string may be searched.
1615 * If it is negative, it has the same effect as if it were -1:
1616 * -1 is returned.
1617 * @return the index of the last occurrence of the character in the
1618 * character sequence represented by this object that is less
1619 * than or equal to {@code fromIndex}, or {@code -1}
1620 * if the character does not occur before that point.
1621 */
1622 public int lastIndexOf(int ch, int fromIndex) {
1623 if (ch < Character.MIN_SUPPLEMENTARY_CODE_POINT) {
1624 // handle most cases here (ch is a BMP code point or a
1625 // negative value (invalid code point))
1626 final char[] value = this.value;
1627 int i = Math.min(fromIndex, value.length - 1);
1628 for (; i >= 0; i--) {
1629 if (value[i] == ch) {
1630 return i;
1631 }
1632 }
1633 return -1;
1634 } else {
1635 return lastIndexOfSupplementary(ch, fromIndex);
1636 }
1637 }
1638
1639 /**
1640 * Handles (rare) calls of lastIndexOf with a supplementary character.
1641 */
1642 private int lastIndexOfSupplementary(int ch, int fromIndex) {
1643 if (Character.isValidCodePoint(ch)) {
1644 final char[] value = this.value;
1645 char hi = Character.highSurrogate(ch);
1646 char lo = Character.lowSurrogate(ch);
1647 int i = Math.min(fromIndex, value.length - 2);
1648 for (; i >= 0; i--) {
1649 if (value[i] == hi && value[i + 1] == lo) {
1650 return i;
1651 }
1652 }
1653 }
1654 return -1;
1655 }
1656
1657 /**
1658 * Returns the index within this string of the first occurrence of the
1659 * specified substring.
1660 *
1661 * <p>The returned index is the smallest value <i>k</i> for which:
1662 * <blockquote><pre>
1663 * this.startsWith(str, <i>k</i>)
1664 * </pre></blockquote>
1665 * If no such value of <i>k</i> exists, then {@code -1} is returned.
1666 *
1667 * @param str the substring to search for.
1668 * @return the index of the first occurrence of the specified substring,
1669 * or {@code -1} if there is no such occurrence.
1670 */
1671 public int indexOf(String str) {
1672 return indexOf(str, 0);
1673 }
1674
1675 /**
1676 * Returns the index within this string of the first occurrence of the
1677 * specified substring, starting at the specified index.
1678 *
1679 * <p>The returned index is the smallest value <i>k</i> for which:
1680 * <blockquote><pre>
1681 * <i>k</i> >= fromIndex && this.startsWith(str, <i>k</i>)
1682 * </pre></blockquote>
1683 * If no such value of <i>k</i> exists, then {@code -1} is returned.
1684 *
1685 * @param str the substring to search for.
1686 * @param fromIndex the index from which to start the search.
1687 * @return the index of the first occurrence of the specified substring,
1688 * starting at the specified index,
1689 * or {@code -1} if there is no such occurrence.
1690 */
1691 public int indexOf(String str, int fromIndex) {
1692 return indexOf(value, 0, value.length,
1693 str.value, 0, str.value.length, fromIndex);
1694 }
1695
1696 /**
1697 * Code shared by String and StringBuffer to do searches. The
1698 * source is the character array being searched, and the target
1699 * is the string being searched for.
1700 *
1701 * @param source the characters being searched.
1702 * @param sourceOffset offset of the source string.
1703 * @param sourceCount count of the source string.
1704 * @param target the characters being searched for.
1705 * @param targetOffset offset of the target string.
1706 * @param targetCount count of the target string.
1707 * @param fromIndex the index to begin searching from.
1708 */
1709 static int indexOf(char[] source, int sourceOffset, int sourceCount,
1710 char[] target, int targetOffset, int targetCount,
1711 int fromIndex) {
1712 if (fromIndex >= sourceCount) {
1713 return (targetCount == 0 ? sourceCount : -1);
1714 }
1715 if (fromIndex < 0) {
1716 fromIndex = 0;
1717 }
1718 if (targetCount == 0) {
1719 return fromIndex;
1720 }
1721
1722 char first = target[targetOffset];
1723 int max = sourceOffset + (sourceCount - targetCount);
1724
1725 for (int i = sourceOffset + fromIndex; i <= max; i++) {
1726 /* Look for first character. */
1727 if (source[i] != first) {
1728 while (++i <= max && source[i] != first);
1729 }
1730
1731 /* Found first character, now look at the rest of v2 */
1732 if (i <= max) {
1733 int j = i + 1;
1734 int end = j + targetCount - 1;
1735 for (int k = targetOffset + 1; j < end && source[j]
1736 == target[k]; j++, k++);
1737
1738 if (j == end) {
1739 /* Found whole string. */
1740 return i - sourceOffset;
1741 }
1742 }
1743 }
1744 return -1;
1745 }
1746
1747 /**
1748 * Returns the index within this string of the last occurrence of the
1749 * specified substring. The last occurrence of the empty string ""
1750 * is considered to occur at the index value {@code this.length()}.
1751 *
1752 * <p>The returned index is the largest value <i>k</i> for which:
1753 * <blockquote><pre>
1754 * this.startsWith(str, <i>k</i>)
1755 * </pre></blockquote>
1756 * If no such value of <i>k</i> exists, then {@code -1} is returned.
1757 *
1758 * @param str the substring to search for.
1759 * @return the index of the last occurrence of the specified substring,
1760 * or {@code -1} if there is no such occurrence.
1761 */
1762 public int lastIndexOf(String str) {
1763 return lastIndexOf(str, value.length);
1764 }
1765
1766 /**
1767 * Returns the index within this string of the last occurrence of the
1768 * specified substring, searching backward starting at the specified index.
1769 *
1770 * <p>The returned index is the largest value <i>k</i> for which:
1771 * <blockquote><pre>
1772 * <i>k</i> <= fromIndex && this.startsWith(str, <i>k</i>)
1773 * </pre></blockquote>
1774 * If no such value of <i>k</i> exists, then {@code -1} is returned.
1775 *
1776 * @param str the substring to search for.
1777 * @param fromIndex the index to start the search from.
1778 * @return the index of the last occurrence of the specified substring,
1779 * searching backward from the specified index,
1780 * or {@code -1} if there is no such occurrence.
1781 */
1782 public int lastIndexOf(String str, int fromIndex) {
1783 return lastIndexOf(value, 0, value.length,
1784 str.value, 0, str.value.length, fromIndex);
1785 }
1786
1787 /**
1788 * Code shared by String and StringBuffer to do searches. The
1789 * source is the character array being searched, and the target
1790 * is the string being searched for.
1791 *
1792 * @param source the characters being searched.
1793 * @param sourceOffset offset of the source string.
1794 * @param sourceCount count of the source string.
1795 * @param target the characters being searched for.
1796 * @param targetOffset offset of the target string.
1797 * @param targetCount count of the target string.
1798 * @param fromIndex the index to begin searching from.
1799 */
1800 static int lastIndexOf(char[] source, int sourceOffset, int sourceCount,
1801 char[] target, int targetOffset, int targetCount,
1802 int fromIndex) {
1803 /*
1804 * Check arguments; return immediately where possible. For
1805 * consistency, don't check for null str.
1806 */
1807 int rightIndex = sourceCount - targetCount;
1808 if (fromIndex < 0) {
1809 return -1;
1810 }
1811 if (fromIndex > rightIndex) {
1812 fromIndex = rightIndex;
1813 }
1814 /* Empty string always matches. */
1815 if (targetCount == 0) {
1816 return fromIndex;
1817 }
1818
1819 int strLastIndex = targetOffset + targetCount - 1;
1820 char strLastChar = target[strLastIndex];
1821 int min = sourceOffset + targetCount - 1;
1822 int i = min + fromIndex;
1823
1824 startSearchForLastChar:
1825 while (true) {
1826 while (i >= min && source[i] != strLastChar) {
1827 i--;
1828 }
1829 if (i < min) {
1830 return -1;
1831 }
1832 int j = i - 1;
1833 int start = j - (targetCount - 1);
1834 int k = strLastIndex - 1;
1835
1836 while (j > start) {
1837 if (source[j--] != target[k--]) {
1838 i--;
1839 continue startSearchForLastChar;
1840 }
1841 }
1842 return start - sourceOffset + 1;
1843 }
1844 }
1845
1846 /**
1847 * Returns a new string that is a substring of this string. The
1848 * substring begins with the character at the specified index and
1849 * extends to the end of this string. <p>
1850 * Examples:
1851 * <blockquote><pre>
1852 * "unhappy".substring(2) returns "happy"
1853 * "Harbison".substring(3) returns "bison"
1854 * "emptiness".substring(9) returns "" (an empty string)
1855 * </pre></blockquote>
1856 *
1857 * @param beginIndex the beginning index, inclusive.
1858 * @return the specified substring.
1859 * @exception IndexOutOfBoundsException if
1860 * {@code beginIndex} is negative or larger than the
1861 * length of this {@code String} object.
1862 */
1863 public String substring(int beginIndex) {
1864 if (beginIndex < 0) {
1865 throw new StringIndexOutOfBoundsException(beginIndex);
1866 }
1867 int subLen = value.length - beginIndex;
1868 if (subLen < 0) {
1869 throw new StringIndexOutOfBoundsException(subLen);
1870 }
1871 return (beginIndex == 0) ? this : new String(value, beginIndex, subLen);
1872 }
1873
1874 /**
1875 * Returns a new string that is a substring of this string. The
1876 * substring begins at the specified {@code beginIndex} and
1877 * extends to the character at index {@code endIndex - 1}.
1878 * Thus the length of the substring is {@code endIndex-beginIndex}.
1879 * <p>
1880 * Examples:
1881 * <blockquote><pre>
1882 * "hamburger".substring(4, 8) returns "urge"
1883 * "smiles".substring(1, 5) returns "mile"
1884 * </pre></blockquote>
1885 *
1886 * @param beginIndex the beginning index, inclusive.
1887 * @param endIndex the ending index, exclusive.
1888 * @return the specified substring.
1889 * @exception IndexOutOfBoundsException if the
1890 * {@code beginIndex} is negative, or
1891 * {@code endIndex} is larger than the length of
1892 * this {@code String} object, or
1893 * {@code beginIndex} is larger than
1894 * {@code endIndex}.
1895 */
1896 public String substring(int beginIndex, int endIndex) {
1897 if (beginIndex < 0) {
1898 throw new StringIndexOutOfBoundsException(beginIndex);
1899 }
1900 if (endIndex > value.length) {
1901 throw new StringIndexOutOfBoundsException(endIndex);
1902 }
1903 int subLen = endIndex - beginIndex;
1904 if (subLen < 0) {
1905 throw new StringIndexOutOfBoundsException(subLen);
1906 }
1907 return ((beginIndex == 0) && (endIndex == value.length)) ? this
1908 : new String(value, beginIndex, subLen);
1909 }
1910
1911 /**
1912 * Returns a new character sequence that is a subsequence of this sequence.
1913 *
1914 * <p> An invocation of this method of the form
1915 *
1916 * <blockquote><pre>
1917 * str.subSequence(begin, end)</pre></blockquote>
1918 *
1919 * behaves in exactly the same way as the invocation
1920 *
1921 * <blockquote><pre>
1922 * str.substring(begin, end)</pre></blockquote>
1923 *
1924 * This method is defined so that the {@code String} class can implement
1925 * the {@link CharSequence} interface. </p>
1926 *
1927 * @param beginIndex the begin index, inclusive.
1928 * @param endIndex the end index, exclusive.
1929 * @return the specified subsequence.
1930 *
1931 * @throws IndexOutOfBoundsException
1932 * if {@code beginIndex} or {@code endIndex} is negative,
1933 * if {@code endIndex} is greater than {@code length()},
1934 * or if {@code beginIndex} is greater than {@code endIndex}
1935 *
1936 * @since 1.4
1937 * @spec JSR-51
1938 */
1939 public CharSequence subSequence(int beginIndex, int endIndex) {
1940 return this.substring(beginIndex, endIndex);
1941 }
1942
1943 /**
1944 * Concatenates the specified string to the end of this string.
1945 * <p>
1946 * If the length of the argument string is {@code 0}, then this
1947 * {@code String} object is returned. Otherwise, a new
1948 * {@code String} object is created, representing a character
1949 * sequence that is the concatenation of the character sequence
1950 * represented by this {@code String} object and the character
1951 * sequence represented by the argument string.<p>
1952 * Examples:
1953 * <blockquote><pre>
1954 * "cares".concat("s") returns "caress"
1955 * "to".concat("get").concat("her") returns "together"
1956 * </pre></blockquote>
1957 *
1958 * @param str the {@code String} that is concatenated to the end
1959 * of this {@code String}.
1960 * @return a string that represents the concatenation of this object's
1961 * characters followed by the string argument's characters.
1962 */
1963 public String concat(String str) {
1964 int otherLen = str.length();
1965 if (otherLen == 0) {
1966 return this;
1967 }
1968 int len = value.length;
1969 char buf[] = Arrays.copyOf(value, len + otherLen);
1970 str.getChars(buf, len);
1971 return new String(buf, true);
1972 }
1973
1974 /**
1975 * Returns a new string resulting from replacing all occurrences of
1976 * {@code oldChar} in this string with {@code newChar}.
1977 * <p>
1978 * If the character {@code oldChar} does not occur in the
1979 * character sequence represented by this {@code String} object,
1980 * then a reference to this {@code String} object is returned.
1981 * Otherwise, a new {@code String} object is created that
1982 * represents a character sequence identical to the character sequence
1983 * represented by this {@code String} object, except that every
1984 * occurrence of {@code oldChar} is replaced by an occurrence
1985 * of {@code newChar}.
1986 * <p>
1987 * Examples:
1988 * <blockquote><pre>
1989 * "mesquite in your cellar".replace('e', 'o')
1990 * returns "mosquito in your collar"
1991 * "the war of baronets".replace('r', 'y')
1992 * returns "the way of bayonets"
1993 * "sparring with a purple porpoise".replace('p', 't')
1994 * returns "starring with a turtle tortoise"
1995 * "JonL".replace('q', 'x') returns "JonL" (no change)
1996 * </pre></blockquote>
1997 *
1998 * @param oldChar the old character.
1999 * @param newChar the new character.
2000 * @return a string derived from this string by replacing every
2001 * occurrence of {@code oldChar} with {@code newChar}.
2002 */
2003 public String replace(char oldChar, char newChar) {
2004 if (oldChar != newChar) {
2005 int len = value.length;
2006 int i = -1;
2007 char[] val = value; /* avoid getfield opcode */
2008
2009 while (++i < len) {
2010 if (val[i] == oldChar) {
2011 break;
2012 }
2013 }
2014 if (i < len) {
2015 char buf[] = new char[len];
2016 for (int j = 0; j < i; j++) {
2017 buf[j] = val[j];
2018 }
2019 while (i < len) {
2020 char c = val[i];
2021 buf[i] = (c == oldChar) ? newChar : c;
2022 i++;
2023 }
2024 return new String(buf, true);
2025 }
2026 }
2027 return this;
2028 }
2029
2030 /**
2031 * Tells whether or not this string matches the given <a
2032 * href="../util/regex/Pattern.html#sum">regular expression</a>.
2033 *
2034 * <p> An invocation of this method of the form
2035 * <i>str</i><tt>.matches(</tt><i>regex</i><tt>)</tt> yields exactly the
2036 * same result as the expression
2037 *
2038 * <blockquote><tt> {@link java.util.regex.Pattern}.{@link
2039 * java.util.regex.Pattern#matches(String,CharSequence)
2040 * matches}(</tt><i>regex</i><tt>,</tt> <i>str</i><tt>)</tt></blockquote>
2041 *
2042 * @param regex
2043 * the regular expression to which this string is to be matched
2044 *
2045 * @return <tt>true</tt> if, and only if, this string matches the
2046 * given regular expression
2047 *
2048 * @throws PatternSyntaxException
2049 * if the regular expression's syntax is invalid
2050 *
2051 * @see java.util.regex.Pattern
2052 *
2053 * @since 1.4
2054 * @spec JSR-51
2055 */
2056 public boolean matches(String regex) {
2057 return Pattern.matches(regex, this);
2058 }
2059
2060 /**
2061 * Returns true if and only if this string contains the specified
2062 * sequence of char values.
2063 *
2064 * @param s the sequence to search for
2065 * @return true if this string contains {@code s}, false otherwise
2066 * @throws NullPointerException if {@code s} is {@code null}
2067 * @since 1.5
2068 */
2069 public boolean contains(CharSequence s) {
2070 return indexOf(s.toString()) > -1;
2071 }
2072
2073 /**
2074 * Replaces the first substring of this string that matches the given <a
2075 * href="../util/regex/Pattern.html#sum">regular expression</a> with the
2076 * given replacement.
2077 *
2078 * <p> An invocation of this method of the form
2079 * <i>str</i><tt>.replaceFirst(</tt><i>regex</i><tt>,</tt> <i>repl</i><tt>)</tt>
2080 * yields exactly the same result as the expression
2081 *
2082 * <blockquote><tt>
2083 * {@link java.util.regex.Pattern}.{@link java.util.regex.Pattern#compile
2084 * compile}(</tt><i>regex</i><tt>).{@link
2085 * java.util.regex.Pattern#matcher(java.lang.CharSequence)
2086 * matcher}(</tt><i>str</i><tt>).{@link java.util.regex.Matcher#replaceFirst
2087 * replaceFirst}(</tt><i>repl</i><tt>)</tt></blockquote>
2088 *
2089 *<p>
2090 * Note that backslashes (<tt>\</tt>) and dollar signs (<tt>$</tt>) in the
2091 * replacement string may cause the results to be different than if it were
2092 * being treated as a literal replacement string; see
2093 * {@link java.util.regex.Matcher#replaceFirst}.
2094 * Use {@link java.util.regex.Matcher#quoteReplacement} to suppress the special
2095 * meaning of these characters, if desired.
2096 *
2097 * @param regex
2098 * the regular expression to which this string is to be matched
2099 * @param replacement
2100 * the string to be substituted for the first match
2101 *
2102 * @return The resulting <tt>String</tt>
2103 *
2104 * @throws PatternSyntaxException
2105 * if the regular expression's syntax is invalid
2106 *
2107 * @see java.util.regex.Pattern
2108 *
2109 * @since 1.4
2110 * @spec JSR-51
2111 */
2112 public String replaceFirst(String regex, String replacement) {
2113 return Pattern.compile(regex).matcher(this).replaceFirst(replacement);
2114 }
2115
2116 /**
2117 * Replaces each substring of this string that matches the given <a
2118 * href="../util/regex/Pattern.html#sum">regular expression</a> with the
2119 * given replacement.
2120 *
2121 * <p> An invocation of this method of the form
2122 * <i>str</i><tt>.replaceAll(</tt><i>regex</i><tt>,</tt> <i>repl</i><tt>)</tt>
2123 * yields exactly the same result as the expression
2124 *
2125 * <blockquote><tt>
2126 * {@link java.util.regex.Pattern}.{@link java.util.regex.Pattern#compile
2127 * compile}(</tt><i>regex</i><tt>).{@link
2128 * java.util.regex.Pattern#matcher(java.lang.CharSequence)
2129 * matcher}(</tt><i>str</i><tt>).{@link java.util.regex.Matcher#replaceAll
2130 * replaceAll}(</tt><i>repl</i><tt>)</tt></blockquote>
2131 *
2132 *<p>
2133 * Note that backslashes (<tt>\</tt>) and dollar signs (<tt>$</tt>) in the
2134 * replacement string may cause the results to be different than if it were
2135 * being treated as a literal replacement string; see
2136 * {@link java.util.regex.Matcher#replaceAll Matcher.replaceAll}.
2137 * Use {@link java.util.regex.Matcher#quoteReplacement} to suppress the special
2138 * meaning of these characters, if desired.
2139 *
2140 * @param regex
2141 * the regular expression to which this string is to be matched
2142 * @param replacement
2143 * the string to be substituted for each match
2144 *
2145 * @return The resulting <tt>String</tt>
2146 *
2147 * @throws PatternSyntaxException
2148 * if the regular expression's syntax is invalid
2149 *
2150 * @see java.util.regex.Pattern
2151 *
2152 * @since 1.4
2153 * @spec JSR-51
2154 */
2155 public String replaceAll(String regex, String replacement) {
2156 return Pattern.compile(regex).matcher(this).replaceAll(replacement);
2157 }
2158
2159 /**
2160 * Replaces each substring of this string that matches the literal target
2161 * sequence with the specified literal replacement sequence. The
2162 * replacement proceeds from the beginning of the string to the end, for
2163 * example, replacing "aa" with "b" in the string "aaa" will result in
2164 * "ba" rather than "ab".
2165 *
2166 * @param target The sequence of char values to be replaced
2167 * @param replacement The replacement sequence of char values
2168 * @return The resulting string
2169 * @throws NullPointerException if {@code target} or
2170 * {@code replacement} is {@code null}.
2171 * @since 1.5
2172 */
2173 public String replace(CharSequence target, CharSequence replacement) {
2174 return Pattern.compile(target.toString(), Pattern.LITERAL).matcher(
2175 this).replaceAll(Matcher.quoteReplacement(replacement.toString()));
2176 }
2177
2178 /**
2179 * Splits this string around matches of the given
2180 * <a href="../util/regex/Pattern.html#sum">regular expression</a>.
2181 *
2182 * <p> The array returned by this method contains each substring of this
2183 * string that is terminated by another substring that matches the given
2184 * expression or is terminated by the end of the string. The substrings in
2185 * the array are in the order in which they occur in this string. If the
2186 * expression does not match any part of the input then the resulting array
2187 * has just one element, namely this string.
2188 *
2189 * <p> The <tt>limit</tt> parameter controls the number of times the
2190 * pattern is applied and therefore affects the length of the resulting
2191 * array. If the limit <i>n</i> is greater than zero then the pattern
2192 * will be applied at most <i>n</i> - 1 times, the array's
2193 * length will be no greater than <i>n</i>, and the array's last entry
2194 * will contain all input beyond the last matched delimiter. If <i>n</i>
2195 * is non-positive then the pattern will be applied as many times as
2196 * possible and the array can have any length. If <i>n</i> is zero then
2197 * the pattern will be applied as many times as possible, the array can
2198 * have any length, and trailing empty strings will be discarded.
2199 *
2200 * <p> The string <tt>"boo:and:foo"</tt>, for example, yields the
2201 * following results with these parameters:
2202 *
2203 * <blockquote><table cellpadding=1 cellspacing=0 summary="Split example showing regex, limit, and result">
2204 * <tr>
2205 * <th>Regex</th>
2206 * <th>Limit</th>
2207 * <th>Result</th>
2208 * </tr>
2209 * <tr><td align=center>:</td>
2210 * <td align=center>2</td>
2211 * <td><tt>{ "boo", "and:foo" }</tt></td></tr>
2212 * <tr><td align=center>:</td>
2213 * <td align=center>5</td>
2214 * <td><tt>{ "boo", "and", "foo" }</tt></td></tr>
2215 * <tr><td align=center>:</td>
2216 * <td align=center>-2</td>
2217 * <td><tt>{ "boo", "and", "foo" }</tt></td></tr>
2218 * <tr><td align=center>o</td>
2219 * <td align=center>5</td>
2220 * <td><tt>{ "b", "", ":and:f", "", "" }</tt></td></tr>
2221 * <tr><td align=center>o</td>
2222 * <td align=center>-2</td>
2223 * <td><tt>{ "b", "", ":and:f", "", "" }</tt></td></tr>
2224 * <tr><td align=center>o</td>
2225 * <td align=center>0</td>
2226 * <td><tt>{ "b", "", ":and:f" }</tt></td></tr>
2227 * </table></blockquote>
2228 *
2229 * <p> An invocation of this method of the form
2230 * <i>str.</i><tt>split(</tt><i>regex</i><tt>,</tt> <i>n</i><tt>)</tt>
2231 * yields the same result as the expression
2232 *
2233 * <blockquote>
2234 * {@link java.util.regex.Pattern}.{@link java.util.regex.Pattern#compile
2235 * compile}<tt>(</tt><i>regex</i><tt>)</tt>.{@link
2236 * java.util.regex.Pattern#split(java.lang.CharSequence,int)
2237 * split}<tt>(</tt><i>str</i><tt>,</tt> <i>n</i><tt>)</tt>
2238 * </blockquote>
2239 *
2240 *
2241 * @param regex
2242 * the delimiting regular expression
2243 *
2244 * @param limit
2245 * the result threshold, as described above
2246 *
2247 * @return the array of strings computed by splitting this string
2248 * around matches of the given regular expression
2249 *
2250 * @throws PatternSyntaxException
2251 * if the regular expression's syntax is invalid
2252 *
2253 * @see java.util.regex.Pattern
2254 *
2255 * @since 1.4
2256 * @spec JSR-51
2257 */
2258 public String[] split(String regex, int limit) {
2259 /* fastpath if the regex is a
2260 (1)one-char String and this character is not one of the
2261 RegEx's meta characters ".$|()[{^?*+\\", or
2262 (2)two-char String and the first char is the backslash and
2263 the second is not the ascii digit or ascii letter.
2264 */
2265 char ch = 0;
2266 if (((regex.value.length == 1 &&
2267 ".$|()[{^?*+\\".indexOf(ch = regex.charAt(0)) == -1) ||
2268 (regex.length() == 2 &&
2269 regex.charAt(0) == '\\' &&
2270 (((ch = regex.charAt(1))-'0')|('9'-ch)) < 0 &&
2271 ((ch-'a')|('z'-ch)) < 0 &&
2272 ((ch-'A')|('Z'-ch)) < 0)) &&
2273 (ch < Character.MIN_HIGH_SURROGATE ||
2274 ch > Character.MAX_LOW_SURROGATE))
2275 {
2276 int off = 0;
2277 int next = 0;
2278 boolean limited = limit > 0;
2279 ArrayList<String> list = new ArrayList<>();
2280 while ((next = indexOf(ch, off)) != -1) {
2281 if (!limited || list.size() < limit - 1) {
2282 list.add(substring(off, next));
2283 off = next + 1;
2284 } else { // last one
2285 //assert (list.size() == limit - 1);
2286 list.add(substring(off, value.length));
2287 off = value.length;
2288 break;
2289 }
2290 }
2291 // If no match was found, return this
2292 if (off == 0)
2293 return new String[]{this};
2294
2295 // Add remaining segment
2296 if (!limited || list.size() < limit)
2297 list.add(substring(off, value.length));
2298
2299 // Construct result
2300 int resultSize = list.size();
2301 if (limit == 0)
2302 while (resultSize > 0 && list.get(resultSize - 1).length() == 0)
2303 resultSize--;
2304 String[] result = new String[resultSize];
2305 return list.subList(0, resultSize).toArray(result);
2306 }
2307 return Pattern.compile(regex).split(this, limit);
2308 }
2309
2310 /**
2311 * Splits this string around matches of the given <a
2312 * href="../util/regex/Pattern.html#sum">regular expression</a>.
2313 *
2314 * <p> This method works as if by invoking the two-argument {@link
2315 * #split(String, int) split} method with the given expression and a limit
2316 * argument of zero. Trailing empty strings are therefore not included in
2317 * the resulting array.
2318 *
2319 * <p> The string <tt>"boo:and:foo"</tt>, for example, yields the following
2320 * results with these expressions:
2321 *
2322 * <blockquote><table cellpadding=1 cellspacing=0 summary="Split examples showing regex and result">
2323 * <tr>
2324 * <th>Regex</th>
2325 * <th>Result</th>
2326 * </tr>
2327 * <tr><td align=center>:</td>
2328 * <td><tt>{ "boo", "and", "foo" }</tt></td></tr>
2329 * <tr><td align=center>o</td>
2330 * <td><tt>{ "b", "", ":and:f" }</tt></td></tr>
2331 * </table></blockquote>
2332 *
2333 *
2334 * @param regex
2335 * the delimiting regular expression
2336 *
2337 * @return the array of strings computed by splitting this string
2338 * around matches of the given regular expression
2339 *
2340 * @throws PatternSyntaxException
2341 * if the regular expression's syntax is invalid
2342 *
2343 * @see java.util.regex.Pattern
2344 *
2345 * @since 1.4
2346 * @spec JSR-51
2347 */
2348 public String[] split(String regex) {
2349 return split(regex, 0);
2350 }
2351
2352 /**
2353 * Converts all of the characters in this {@code String} to lower
2354 * case using the rules of the given {@code Locale}. Case mapping is based
2355 * on the Unicode Standard version specified by the {@link java.lang.Character Character}
2356 * class. Since case mappings are not always 1:1 char mappings, the resulting
2357 * {@code String} may be a different length than the original {@code String}.
2358 * <p>
2359 * Examples of lowercase mappings are in the following table:
2360 * <table border="1" summary="Lowercase mapping examples showing language code of locale, upper case, lower case, and description">
2361 * <tr>
2362 * <th>Language Code of Locale</th>
2363 * <th>Upper Case</th>
2364 * <th>Lower Case</th>
2365 * <th>Description</th>
2366 * </tr>
2367 * <tr>
2368 * <td>tr (Turkish)</td>
2369 * <td>\u0130</td>
2370 * <td>\u0069</td>
2371 * <td>capital letter I with dot above -> small letter i</td>
2372 * </tr>
2373 * <tr>
2374 * <td>tr (Turkish)</td>
2375 * <td>\u0049</td>
2376 * <td>\u0131</td>
2377 * <td>capital letter I -> small letter dotless i </td>
2378 * </tr>
2379 * <tr>
2380 * <td>(all)</td>
2381 * <td>French Fries</td>
2382 * <td>french fries</td>
2383 * <td>lowercased all chars in String</td>
2384 * </tr>
2385 * <tr>
2386 * <td>(all)</td>
2387 * <td><img src="doc-files/capiota.gif" alt="capiota"><img src="doc-files/capchi.gif" alt="capchi">
2388 * <img src="doc-files/captheta.gif" alt="captheta"><img src="doc-files/capupsil.gif" alt="capupsil">
2389 * <img src="doc-files/capsigma.gif" alt="capsigma"></td>
2390 * <td><img src="doc-files/iota.gif" alt="iota"><img src="doc-files/chi.gif" alt="chi">
2391 * <img src="doc-files/theta.gif" alt="theta"><img src="doc-files/upsilon.gif" alt="upsilon">
2392 * <img src="doc-files/sigma1.gif" alt="sigma"></td>
2393 * <td>lowercased all chars in String</td>
2394 * </tr>
2395 * </table>
2396 *
2397 * @param locale use the case transformation rules for this locale
2398 * @return the {@code String}, converted to lowercase.
2399 * @see java.lang.String#toLowerCase()
2400 * @see java.lang.String#toUpperCase()
2401 * @see java.lang.String#toUpperCase(Locale)
2402 * @since 1.1
2403 */
2404 public String toLowerCase(Locale locale) {
2405 if (locale == null) {
2406 throw new NullPointerException();
2407 }
2408
2409 int firstUpper;
2410 final int len = value.length;
2411
2412 /* Now check if there are any characters that need to be changed. */
2413 scan: {
2414 for (firstUpper = 0 ; firstUpper < len; ) {
2415 char c = value[firstUpper];
2416 if ((c >= Character.MIN_HIGH_SURROGATE)
2417 && (c <= Character.MAX_HIGH_SURROGATE)) {
2418 int supplChar = codePointAt(firstUpper);
2419 if (supplChar != Character.toLowerCase(supplChar)) {
2420 break scan;
2421 }
2422 firstUpper += Character.charCount(supplChar);
2423 } else {
2424 if (c != Character.toLowerCase(c)) {
2425 break scan;
2426 }
2427 firstUpper++;
2428 }
2429 }
2430 return this;
2431 }
2432
2433 char[] result = new char[len];
2434 int resultOffset = 0; /* result may grow, so i+resultOffset
2435 * is the write location in result */
2436
2437 /* Just copy the first few lowerCase characters. */
2438 System.arraycopy(value, 0, result, 0, firstUpper);
2439
2440 String lang = locale.getLanguage();
2441 boolean localeDependent =
2442 (lang == "tr" || lang == "az" || lang == "lt");
2443 char[] lowerCharArray;
2444 int lowerChar;
2445 int srcChar;
2446 int srcCount;
2447 for (int i = firstUpper; i < len; i += srcCount) {
2448 srcChar = (int)value[i];
2449 if ((char)srcChar >= Character.MIN_HIGH_SURROGATE
2450 && (char)srcChar <= Character.MAX_HIGH_SURROGATE) {
2451 srcChar = codePointAt(i);
2452 srcCount = Character.charCount(srcChar);
2453 } else {
2454 srcCount = 1;
2455 }
2456 if (localeDependent || srcChar == '\u03A3') { // GREEK CAPITAL LETTER SIGMA
2457 lowerChar = ConditionalSpecialCasing.toLowerCaseEx(this, i, locale);
2458 } else if (srcChar == '\u0130') { // LATIN CAPITAL LETTER I DOT
2459 lowerChar = Character.ERROR;
2460 } else {
2461 lowerChar = Character.toLowerCase(srcChar);
2462 }
2463 if ((lowerChar == Character.ERROR)
2464 || (lowerChar >= Character.MIN_SUPPLEMENTARY_CODE_POINT)) {
2465 if (lowerChar == Character.ERROR) {
2466 if (!localeDependent && srcChar == '\u0130') {
2467 lowerCharArray =
2468 ConditionalSpecialCasing.toLowerCaseCharArray(this, i, Locale.ENGLISH);
2469 } else {
2470 lowerCharArray =
2471 ConditionalSpecialCasing.toLowerCaseCharArray(this, i, locale);
2472 }
2473 } else if (srcCount == 2) {
2474 resultOffset += Character.toChars(lowerChar, result, i + resultOffset) - srcCount;
2475 continue;
2476 } else {
2477 lowerCharArray = Character.toChars(lowerChar);
2478 }
2479
2480 /* Grow result if needed */
2481 int mapLen = lowerCharArray.length;
2482 if (mapLen > srcCount) {
2483 char[] result2 = new char[result.length + mapLen - srcCount];
2484 System.arraycopy(result, 0, result2, 0, i + resultOffset);
2485 result = result2;
2486 }
2487 for (int x = 0; x < mapLen; ++x) {
2488 result[i + resultOffset + x] = lowerCharArray[x];
2489 }
2490 resultOffset += (mapLen - srcCount);
2491 } else {
2492 result[i + resultOffset] = (char)lowerChar;
2493 }
2494 }
2495 return new String(result, 0, len + resultOffset);
2496 }
2497
2498 /**
2499 * Converts all of the characters in this {@code String} to lower
2500 * case using the rules of the default locale. This is equivalent to calling
2501 * {@code toLowerCase(Locale.getDefault())}.
2502 * <p>
2503 * <b>Note:</b> This method is locale sensitive, and may produce unexpected
2504 * results if used for strings that are intended to be interpreted locale
2505 * independently.
2506 * Examples are programming language identifiers, protocol keys, and HTML
2507 * tags.
2508 * For instance, {@code "TITLE".toLowerCase()} in a Turkish locale
2509 * returns {@code "t\u005Cu0131tle"}, where '\u005Cu0131' is the
2510 * LATIN SMALL LETTER DOTLESS I character.
2511 * To obtain correct results for locale insensitive strings, use
2512 * {@code toLowerCase(Locale.ENGLISH)}.
2513 * <p>
2514 * @return the {@code String}, converted to lowercase.
2515 * @see java.lang.String#toLowerCase(Locale)
2516 */
2517 public String toLowerCase() {
2518 return toLowerCase(Locale.getDefault());
2519 }
2520
2521 /**
2522 * Converts all of the characters in this {@code String} to upper
2523 * case using the rules of the given {@code Locale}. Case mapping is based
2524 * on the Unicode Standard version specified by the {@link java.lang.Character Character}
2525 * class. Since case mappings are not always 1:1 char mappings, the resulting
2526 * {@code String} may be a different length than the original {@code String}.
2527 * <p>
2528 * Examples of locale-sensitive and 1:M case mappings are in the following table.
2529 * <p>
2530 * <table border="1" summary="Examples of locale-sensitive and 1:M case mappings. Shows Language code of locale, lower case, upper case, and description.">
2531 * <tr>
2532 * <th>Language Code of Locale</th>
2533 * <th>Lower Case</th>
2534 * <th>Upper Case</th>
2535 * <th>Description</th>
2536 * </tr>
2537 * <tr>
2538 * <td>tr (Turkish)</td>
2539 * <td>\u0069</td>
2540 * <td>\u0130</td>
2541 * <td>small letter i -> capital letter I with dot above</td>
2542 * </tr>
2543 * <tr>
2544 * <td>tr (Turkish)</td>
2545 * <td>\u0131</td>
2546 * <td>\u0049</td>
2547 * <td>small letter dotless i -> capital letter I</td>
2548 * </tr>
2549 * <tr>
2550 * <td>(all)</td>
2551 * <td>\u00df</td>
2552 * <td>\u0053 \u0053</td>
2553 * <td>small letter sharp s -> two letters: SS</td>
2554 * </tr>
2555 * <tr>
2556 * <td>(all)</td>
2557 * <td>Fahrvergnügen</td>
2558 * <td>FAHRVERGNÜGEN</td>
2559 * <td></td>
2560 * </tr>
2561 * </table>
2562 * @param locale use the case transformation rules for this locale
2563 * @return the {@code String}, converted to uppercase.
2564 * @see java.lang.String#toUpperCase()
2565 * @see java.lang.String#toLowerCase()
2566 * @see java.lang.String#toLowerCase(Locale)
2567 * @since 1.1
2568 */
2569 public String toUpperCase(Locale locale) {
2570 if (locale == null) {
2571 throw new NullPointerException();
2572 }
2573
2574 int firstLower;
2575 final int len = value.length;
2576
2577 /* Now check if there are any characters that need to be changed. */
2578 scan: {
2579 for (firstLower = 0 ; firstLower < len; ) {
2580 int c = (int)value[firstLower];
2581 int srcCount;
2582 if ((c >= Character.MIN_HIGH_SURROGATE)
2583 && (c <= Character.MAX_HIGH_SURROGATE)) {
2584 c = codePointAt(firstLower);
2585 srcCount = Character.charCount(c);
2586 } else {
2587 srcCount = 1;
2588 }
2589 int upperCaseChar = Character.toUpperCaseEx(c);
2590 if ((upperCaseChar == Character.ERROR)
2591 || (c != upperCaseChar)) {
2592 break scan;
2593 }
2594 firstLower += srcCount;
2595 }
2596 return this;
2597 }
2598
2599 char[] result = new char[len]; /* may grow */
2600 int resultOffset = 0; /* result may grow, so i+resultOffset
2601 * is the write location in result */
2602
2603 /* Just copy the first few upperCase characters. */
2604 System.arraycopy(value, 0, result, 0, firstLower);
2605
2606 String lang = locale.getLanguage();
2607 boolean localeDependent =
2608 (lang == "tr" || lang == "az" || lang == "lt");
2609 char[] upperCharArray;
2610 int upperChar;
2611 int srcChar;
2612 int srcCount;
2613 for (int i = firstLower; i < len; i += srcCount) {
2614 srcChar = (int)value[i];
2615 if ((char)srcChar >= Character.MIN_HIGH_SURROGATE &&
2616 (char)srcChar <= Character.MAX_HIGH_SURROGATE) {
2617 srcChar = codePointAt(i);
2618 srcCount = Character.charCount(srcChar);
2619 } else {
2620 srcCount = 1;
2621 }
2622 if (localeDependent) {
2623 upperChar = ConditionalSpecialCasing.toUpperCaseEx(this, i, locale);
2624 } else {
2625 upperChar = Character.toUpperCaseEx(srcChar);
2626 }
2627 if ((upperChar == Character.ERROR)
2628 || (upperChar >= Character.MIN_SUPPLEMENTARY_CODE_POINT)) {
2629 if (upperChar == Character.ERROR) {
2630 if (localeDependent) {
2631 upperCharArray =
2632 ConditionalSpecialCasing.toUpperCaseCharArray(this, i, locale);
2633 } else {
2634 upperCharArray = Character.toUpperCaseCharArray(srcChar);
2635 }
2636 } else if (srcCount == 2) {
2637 resultOffset += Character.toChars(upperChar, result, i + resultOffset) - srcCount;
2638 continue;
2639 } else {
2640 upperCharArray = Character.toChars(upperChar);
2641 }
2642
2643 /* Grow result if needed */
2644 int mapLen = upperCharArray.length;
2645 if (mapLen > srcCount) {
2646 char[] result2 = new char[result.length + mapLen - srcCount];
2647 System.arraycopy(result, 0, result2, 0, i + resultOffset);
2648 result = result2;
2649 }
2650 for (int x = 0; x < mapLen; ++x) {
2651 result[i + resultOffset + x] = upperCharArray[x];
2652 }
2653 resultOffset += (mapLen - srcCount);
2654 } else {
2655 result[i + resultOffset] = (char)upperChar;
2656 }
2657 }
2658 return new String(result, 0, len + resultOffset);
2659 }
2660
2661 /**
2662 * Converts all of the characters in this {@code String} to upper
2663 * case using the rules of the default locale. This method is equivalent to
2664 * {@code toUpperCase(Locale.getDefault())}.
2665 * <p>
2666 * <b>Note:</b> This method is locale sensitive, and may produce unexpected
2667 * results if used for strings that are intended to be interpreted locale
2668 * independently.
2669 * Examples are programming language identifiers, protocol keys, and HTML
2670 * tags.
2671 * For instance, {@code "title".toUpperCase()} in a Turkish locale
2672 * returns {@code "T\u005Cu0130TLE"}, where '\u005Cu0130' is the
2673 * LATIN CAPITAL LETTER I WITH DOT ABOVE character.
2674 * To obtain correct results for locale insensitive strings, use
2675 * {@code toUpperCase(Locale.ENGLISH)}.
2676 * <p>
2677 * @return the {@code String}, converted to uppercase.
2678 * @see java.lang.String#toUpperCase(Locale)
2679 */
2680 public String toUpperCase() {
2681 return toUpperCase(Locale.getDefault());
2682 }
2683
2684 /**
2685 * Returns a copy of the string, with leading and trailing whitespace
2686 * omitted.
2687 * <p>
2688 * If this {@code String} object represents an empty character
2689 * sequence, or the first and last characters of character sequence
2690 * represented by this {@code String} object both have codes
2691 * greater than {@code '\u005Cu0020'} (the space character), then a
2692 * reference to this {@code String} object is returned.
2693 * <p>
2694 * Otherwise, if there is no character with a code greater than
2695 * {@code '\u005Cu0020'} in the string, then a new
2696 * {@code String} object representing an empty string is created
2697 * and returned.
2698 * <p>
2699 * Otherwise, let <i>k</i> be the index of the first character in the
2700 * string whose code is greater than {@code '\u005Cu0020'}, and let
2701 * <i>m</i> be the index of the last character in the string whose code
2702 * is greater than {@code '\u005Cu0020'}. A new {@code String}
2703 * object is created, representing the substring of this string that
2704 * begins with the character at index <i>k</i> and ends with the
2705 * character at index <i>m</i>-that is, the result of
2706 * <code>this.substring(<i>k</i>, <i>m</i>+1)</code>.
2707 * <p>
2708 * This method may be used to trim whitespace (as defined above) from
2709 * the beginning and end of a string.
2710 *
2711 * @return A copy of this string with leading and trailing white
2712 * space removed, or this string if it has no leading or
2713 * trailing white space.
2714 */
2715 public String trim() {
2716 int len = value.length;
2717 int st = 0;
2718 char[] val = value; /* avoid getfield opcode */
2719
2720 while ((st < len) && (val[st] <= ' ')) {
2721 st++;
2722 }
2723 while ((st < len) && (val[len - 1] <= ' ')) {
2724 len--;
2725 }
2726 return ((st > 0) || (len < value.length)) ? substring(st, len) : this;
2727 }
2728
2729 /**
2730 * This object (which is already a string!) is itself returned.
2731 *
2732 * @return the string itself.
2733 */
2734 public String toString() {
2735 return this;
2736 }
2737
2738 /**
2739 * Converts this string to a new character array.
2740 *
2741 * @return a newly allocated character array whose length is the length
2742 * of this string and whose contents are initialized to contain
2743 * the character sequence represented by this string.
2744 */
2745 public char[] toCharArray() {
2746 // Cannot use Arrays.copyOf because of class initialization order issues
2747 char result[] = new char[value.length];
2748 System.arraycopy(value, 0, result, 0, value.length);
2749 return result;
2750 }
2751
2752 /**
2753 * Returns a formatted string using the specified format string and
2754 * arguments.
2755 *
2756 * <p> The locale always used is the one returned by {@link
2757 * java.util.Locale#getDefault() Locale.getDefault()}.
2758 *
2759 * @param format
2760 * A <a href="../util/Formatter.html#syntax">format string</a>
2761 *
2762 * @param args
2763 * Arguments referenced by the format specifiers in the format
2764 * string. If there are more arguments than format specifiers, the
2765 * extra arguments are ignored. The number of arguments is
2766 * variable and may be zero. The maximum number of arguments is
2767 * limited by the maximum dimension of a Java array as defined by
2768 * <cite>The Java™ Virtual Machine Specification</cite>.
2769 * The behaviour on a
2770 * <tt>null</tt> argument depends on the <a
2771 * href="../util/Formatter.html#syntax">conversion</a>.
2772 *
2773 * @throws IllegalFormatException
2774 * If a format string contains an illegal syntax, a format
2775 * specifier that is incompatible with the given arguments,
2776 * insufficient arguments given the format string, or other
2777 * illegal conditions. For specification of all possible
2778 * formatting errors, see the <a
2779 * href="../util/Formatter.html#detail">Details</a> section of the
2780 * formatter class specification.
2781 *
2782 * @throws NullPointerException
2783 * If the <tt>format</tt> is <tt>null</tt>
2784 *
2785 * @return A formatted string
2786 *
2787 * @see java.util.Formatter
2788 * @since 1.5
2789 */
2790 public static String format(String format, Object... args) {
2791 return new Formatter().format(format, args).toString();
2792 }
2793
2794 /**
2795 * Returns a formatted string using the specified locale, format string,
2796 * and arguments.
2797 *
2798 * @param l
2799 * The {@linkplain java.util.Locale locale} to apply during
2800 * formatting. If <tt>l</tt> is <tt>null</tt> then no localization
2801 * is applied.
2802 *
2803 * @param format
2804 * A <a href="../util/Formatter.html#syntax">format string</a>
2805 *
2806 * @param args
2807 * Arguments referenced by the format specifiers in the format
2808 * string. If there are more arguments than format specifiers, the
2809 * extra arguments are ignored. The number of arguments is
2810 * variable and may be zero. The maximum number of arguments is
2811 * limited by the maximum dimension of a Java array as defined by
2812 * <cite>The Java™ Virtual Machine Specification</cite>.
2813 * The behaviour on a
2814 * <tt>null</tt> argument depends on the <a
2815 * href="../util/Formatter.html#syntax">conversion</a>.
2816 *
2817 * @throws IllegalFormatException
2818 * If a format string contains an illegal syntax, a format
2819 * specifier that is incompatible with the given arguments,
2820 * insufficient arguments given the format string, or other
2821 * illegal conditions. For specification of all possible
2822 * formatting errors, see the <a
2823 * href="../util/Formatter.html#detail">Details</a> section of the
2824 * formatter class specification
2825 *
2826 * @throws NullPointerException
2827 * If the <tt>format</tt> is <tt>null</tt>
2828 *
2829 * @return A formatted string
2830 *
2831 * @see java.util.Formatter
2832 * @since 1.5
2833 */
2834 public static String format(Locale l, String format, Object... args) {
2835 return new Formatter(l).format(format, args).toString();
2836 }
2837
2838 /**
2839 * Returns the string representation of the {@code Object} argument.
2840 *
2841 * @param obj an {@code Object}.
2842 * @return if the argument is {@code null}, then a string equal to
2843 * {@code "null"}; otherwise, the value of
2844 * {@code obj.toString()} is returned.
2845 * @see java.lang.Object#toString()
2846 */
2847 public static String valueOf(Object obj) {
2848 return (obj == null) ? "null" : obj.toString();
2849 }
2850
2851 /**
2852 * Returns the string representation of the {@code char} array
2853 * argument. The contents of the character array are copied; subsequent
2854 * modification of the character array does not affect the newly
2855 * created string.
2856 *
2857 * @param data a {@code char} array.
2858 * @return a newly allocated string representing the same sequence of
2859 * characters contained in the character array argument.
2860 */
2861 public static String valueOf(char data[]) {
2862 return new String(data);
2863 }
2864
2865 /**
2866 * Returns the string representation of a specific subarray of the
2867 * {@code char} array argument.
2868 * <p>
2869 * The {@code offset} argument is the index of the first
2870 * character of the subarray. The {@code count} argument
2871 * specifies the length of the subarray. The contents of the subarray
2872 * are copied; subsequent modification of the character array does not
2873 * affect the newly created string.
2874 *
2875 * @param data the character array.
2876 * @param offset the initial offset into the value of the
2877 * {@code String}.
2878 * @param count the length of the value of the {@code String}.
2879 * @return a string representing the sequence of characters contained
2880 * in the subarray of the character array argument.
2881 * @exception IndexOutOfBoundsException if {@code offset} is
2882 * negative, or {@code count} is negative, or
2883 * {@code offset+count} is larger than
2884 * {@code data.length}.
2885 */
2886 public static String valueOf(char data[], int offset, int count) {
2887 return new String(data, offset, count);
2888 }
2889
2890 /**
2891 * Returns a String that represents the character sequence in the
2892 * array specified.
2893 *
2894 * @param data the character array.
2895 * @param offset initial offset of the subarray.
2896 * @param count length of the subarray.
2897 * @return a {@code String} that contains the characters of the
2898 * specified subarray of the character array.
2899 */
2900 public static String copyValueOf(char data[], int offset, int count) {
2901 // All public String constructors now copy the data.
2902 return new String(data, offset, count);
2903 }
2904
2905 /**
2906 * Returns a String that represents the character sequence in the
2907 * array specified.
2908 *
2909 * @param data the character array.
2910 * @return a {@code String} that contains the characters of the
2911 * character array.
2912 */
2913 public static String copyValueOf(char data[]) {
2914 return new String(data);
2915 }
2916
2917 /**
2918 * Returns the string representation of the {@code boolean} argument.
2919 *
2920 * @param b a {@code boolean}.
2921 * @return if the argument is {@code true}, a string equal to
2922 * {@code "true"} is returned; otherwise, a string equal to
2923 * {@code "false"} is returned.
2924 */
2925 public static String valueOf(boolean b) {
2926 return b ? "true" : "false";
2927 }
2928
2929 /**
2930 * Returns the string representation of the {@code char}
2931 * argument.
2932 *
2933 * @param c a {@code char}.
2934 * @return a string of length {@code 1} containing
2935 * as its single character the argument {@code c}.
2936 */
2937 public static String valueOf(char c) {
2938 char data[] = {c};
2939 return new String(data, true);
2940 }
2941
2942 /**
2943 * Returns the string representation of the {@code int} argument.
2944 * <p>
2945 * The representation is exactly the one returned by the
2946 * {@code Integer.toString} method of one argument.
2947 *
2948 * @param i an {@code int}.
2949 * @return a string representation of the {@code int} argument.
2950 * @see java.lang.Integer#toString(int, int)
2951 */
2952 public static String valueOf(int i) {
2953 return Integer.toString(i);
2954 }
2955
2956 /**
2957 * Returns the string representation of the {@code long} argument.
2958 * <p>
2959 * The representation is exactly the one returned by the
2960 * {@code Long.toString} method of one argument.
2961 *
2962 * @param l a {@code long}.
2963 * @return a string representation of the {@code long} argument.
2964 * @see java.lang.Long#toString(long)
2965 */
2966 public static String valueOf(long l) {
2967 return Long.toString(l);
2968 }
2969
2970 /**
2971 * Returns the string representation of the {@code float} argument.
2972 * <p>
2973 * The representation is exactly the one returned by the
2974 * {@code Float.toString} method of one argument.
2975 *
2976 * @param f a {@code float}.
2977 * @return a string representation of the {@code float} argument.
2978 * @see java.lang.Float#toString(float)
2979 */
2980 public static String valueOf(float f) {
2981 return Float.toString(f);
2982 }
2983
2984 /**
2985 * Returns the string representation of the {@code double} argument.
2986 * <p>
2987 * The representation is exactly the one returned by the
2988 * {@code Double.toString} method of one argument.
2989 *
2990 * @param d a {@code double}.
2991 * @return a string representation of the {@code double} argument.
2992 * @see java.lang.Double#toString(double)
2993 */
2994 public static String valueOf(double d) {
2995 return Double.toString(d);
2996 }
2997
2998 /**
2999 * Returns a canonical representation for the string object.
3000 * <p>
3001 * A pool of strings, initially empty, is maintained privately by the
3002 * class {@code String}.
3003 * <p>
3004 * When the intern method is invoked, if the pool already contains a
3005 * string equal to this {@code String} object as determined by
3006 * the {@link #equals(Object)} method, then the string from the pool is
3007 * returned. Otherwise, this {@code String} object is added to the
3008 * pool and a reference to this {@code String} object is returned.
3009 * <p>
3010 * It follows that for any two strings {@code s} and {@code t},
3011 * {@code s.intern() == t.intern()} is {@code true}
3012 * if and only if {@code s.equals(t)} is {@code true}.
3013 * <p>
3014 * All literal strings and string-valued constant expressions are
3015 * interned. String literals are defined in section 3.10.5 of the
3016 * <cite>The Java™ Language Specification</cite>.
3017 *
3018 * @return a string that has the same contents as this string, but is
3019 * guaranteed to be from a pool of unique strings.
3020 */
3021 public native String intern();
3022
3023 /**
3024 * Seed value used for each alternative hash calculated.
3025 */
3026 private static final int HASHING_SEED;
3027
3028 static {
3029 long nanos = System.nanoTime();
3030 long now = System.currentTimeMillis();
3031 int SEED_MATERIAL[] = {
3032 System.identityHashCode(String.class),
3033 System.identityHashCode(System.class),
3034 (int) (nanos >>> 32),
3035 (int) nanos,
3036 (int) (now >>> 32),
3037 (int) now,
3038 (int) (System.nanoTime() >>> 2)
3039 };
3040
3041 // Use murmur3 to scramble the seeding material.
3042 // Inline implementation to avoid loading classes
3043 int h1 = 0;
3044
3045 // body
3046 for(int k1 : SEED_MATERIAL) {
3047 k1 *= 0xcc9e2d51;
3048 k1 = (k1 << 15) | (k1 >>> 17);
3049 k1 *= 0x1b873593;
3050
3051 h1 ^= k1;
3052 h1 = (h1 << 13) | (h1 >>> 19);
3053 h1 = h1 * 5 + 0xe6546b64;
3054 }
3055
3056 // tail (always empty, as body is always 32-bit chunks)
3057
3058 // finalization
3059
3060 h1 ^= SEED_MATERIAL.length * 4;
3061
3062 // finalization mix force all bits of a hash block to avalanche
3063 h1 ^= h1 >>> 16;
3064 h1 *= 0x85ebca6b;
3065 h1 ^= h1 >>> 13;
3066 h1 *= 0xc2b2ae35;
3067 h1 ^= h1 >>> 16;
3068
3069 HASHING_SEED = h1;
3070 }
3071
3072 /**
3073 * Cached value of the hashing algorithm result
3074 */
3075 private transient int hash32 = 0;
3076
3077 /**
3078 * Return a 32-bit hash code value for this object.
3079 * <p>
3080 * The general contract of {@code hash32} is:
3081 * <ul>
3082 * <li>Whenever it is invoked on the same object more than once during
3083 * an execution of a Java application, the {@code hash32} method
3084 * must consistently return the same integer, provided no information
3085 * used in {@code equals} comparisons on the object is modified.
3086 * This integer need not remain consistent from one execution of an
3087 * application to another execution of the same application.
3088 * <li>If two objects are equal according to the {@code equals(Object)}
3089 * method, then calling the {@code hash32} method on each of
3090 * the two objects must produce the same integer result.
3091 * <li>It is <em>not</em> required that if two objects are unequal
3092 * according to the {@link java.lang.Object#equals(java.lang.Object)}
3093 * method, then calling the {@code hash32} method on each of the
3094 * two objects must produce distinct integer results. However, the
3095 * programmer should be aware that producing distinct integer results
3096 * for unequal objects may improve the performance of hash tables.
3097 * </ul>
3098 * <p/>
3099 * The hash value will never be zero.
3100 *
3101 * @return a hash code value for this object.
3102 * @see java.lang.Object#equals(java.lang.Object)
3103 */
3104 public int hash32() {
3105 int h = hash32;
3106 if (0 == h) {
3107 // harmless data race on hash32 here.
3108 h = sun.misc.Hashing.murmur3_32(HASHING_SEED, value, 0, value.length);
3109
3110 // ensure result is not zero to avoid recalcing
3111 h = (0 != h) ? h : 1;
3112
3113 hash32 = h;
3114 }
3115
3116 return h;
3117 }
3118
3119 }