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 import sun.misc.Hashing; 40 41 /** 42 * The {@code String} class represents character strings. All 43 * string literals in Java programs, such as {@code "abc"}, are 44 * implemented as instances of this class. 45 * <p> 46 * Strings are constant; their values cannot be changed after they 47 * are created. String buffers support mutable strings. 48 * Because String objects are immutable they can be shared. For example: 49 * <p><blockquote><pre> 50 * String str = "abc"; 51 * </pre></blockquote><p> 52 * is equivalent to: 53 * <p><blockquote><pre> 54 * char data[] = {'a', 'b', 'c'}; 55 * String str = new String(data); 56 * </pre></blockquote><p> 57 * Here are some more examples of how strings can be used: 58 * <p><blockquote><pre> 59 * System.out.println("abc"); 60 * String cde = "cde"; 61 * System.out.println("abc" + cde); 62 * String c = "abc".substring(2,3); 63 * String d = cde.substring(1, 2); 64 * </pre></blockquote> 65 * <p> 66 * The class {@code String} includes methods for examining 67 * individual characters of the sequence, for comparing strings, for 68 * searching strings, for extracting substrings, and for creating a 69 * copy of a string with all characters translated to uppercase or to 70 * lowercase. Case mapping is based on the Unicode Standard version 71 * specified by the {@link java.lang.Character Character} class. 72 * <p> 73 * The Java language provides special support for the string 74 * concatenation operator ( + ), and for conversion of 75 * other objects to strings. String concatenation is implemented 76 * through the {@code StringBuilder}(or {@code StringBuffer}) 77 * class and its {@code append} method. 78 * String conversions are implemented through the method 79 * {@code toString}, defined by {@code Object} and 80 * inherited by all classes in Java. For additional information on 81 * string concatenation and conversion, see Gosling, Joy, and Steele, 82 * <i>The Java Language Specification</i>. 83 * 84 * <p> Unless otherwise noted, passing a <tt>null</tt> argument to a constructor 85 * or method in this class will cause a {@link NullPointerException} to be 86 * thrown. 87 * 88 * <p>A {@code String} represents a string in the UTF-16 format 89 * in which <em>supplementary characters</em> are represented by <em>surrogate 90 * pairs</em> (see the section <a href="Character.html#unicode">Unicode 91 * Character Representations</a> in the {@code Character} class for 92 * more information). 93 * Index values refer to {@code char} code units, so a supplementary 94 * character uses two positions in a {@code String}. 95 * <p>The {@code String} class provides methods for dealing with 96 * Unicode code points (i.e., characters), in addition to those for 97 * dealing with Unicode code units (i.e., {@code char} values). 98 * 99 * @author Lee Boynton 100 * @author Arthur van Hoff 101 * @author Martin Buchholz 102 * @author Ulf Zibis 103 * @see java.lang.Object#toString() 104 * @see java.lang.StringBuffer 105 * @see java.lang.StringBuilder 106 * @see java.nio.charset.Charset 107 * @since JDK1.0 108 */ 109 110 public final class String 111 implements java.io.Serializable, Comparable<String>, CharSequence, Hashable32 112 { 113 /** The value is used for character storage. */ 114 private final char value[]; 115 116 /** The offset is the first index of the storage that is used. */ 117 private final int offset; 118 119 /** The count is the number of characters in the String. */ 120 private final int count; 121 122 /** Cache the hash code for the string */ 123 private int hash; // Default to 0 124 125 /** use serialVersionUID from JDK 1.0.2 for interoperability */ 126 private static final long serialVersionUID = -6849794470754667710L; 127 128 /** 129 * Class String is special cased within the Serialization Stream Protocol. 130 * 131 * A String instance is written initially into an ObjectOutputStream in the 132 * following format: 133 * <pre> 134 * {@code TC_STRING} (utf String) 135 * </pre> 136 * The String is written by method {@code DataOutput.writeUTF}. 137 * A new handle is generated to refer to all future references to the 138 * string instance within the stream. 139 */ 140 private static final ObjectStreamField[] serialPersistentFields = 141 new ObjectStreamField[0]; 142 143 /** 144 * Initializes a newly created {@code String} object so that it represents 145 * an empty character sequence. Note that use of this constructor is 146 * unnecessary since Strings are immutable. 147 */ 148 public String() { 149 this.offset = 0; 150 this.count = 0; 151 this.value = new char[0]; 152 } 153 154 /** 155 * Initializes a newly created {@code String} object so that it represents 156 * the same sequence of characters as the argument; in other words, the 157 * newly created string is a copy of the argument string. Unless an 158 * explicit copy of {@code original} is needed, use of this constructor is 159 * unnecessary since Strings are immutable. 160 * 161 * @param original 162 * A {@code String} 163 */ 164 public String(String original) { 165 int size = original.count; 166 char[] originalValue = original.value; 167 char[] v; 168 if (originalValue.length > size) { 169 // The array representing the String is bigger than the new 170 // String itself. Perhaps this constructor is being called 171 // in order to trim the baggage, so make a copy of the array. 172 int off = original.offset; 173 v = Arrays.copyOfRange(originalValue, off, off+size); 174 } else { 175 // The array representing the String is the same 176 // size as the String, so no point in making a copy. 177 v = originalValue; 178 } 179 this.offset = 0; 180 this.count = size; 181 this.value = v; 182 } 183 184 /** 185 * Allocates a new {@code String} so that it represents the sequence of 186 * characters currently contained in the character array argument. The 187 * contents of the character array are copied; subsequent modification of 188 * the character array does not affect the newly created string. 189 * 190 * @param value 191 * The initial value of the string 192 */ 193 public String(char value[]) { 194 int size = value.length; 195 this.offset = 0; 196 this.count = size; 197 this.value = Arrays.copyOf(value, size); 198 } 199 200 /** 201 * Allocates a new {@code String} that contains characters from a subarray 202 * of the character array argument. The {@code offset} argument is the 203 * index of the first character of the subarray and the {@code count} 204 * argument specifies the length of the subarray. The contents of the 205 * subarray are copied; subsequent modification of the character array does 206 * not affect the newly created string. 207 * 208 * @param value 209 * Array that is the source of characters 210 * 211 * @param offset 212 * The initial offset 213 * 214 * @param count 215 * The length 216 * 217 * @throws IndexOutOfBoundsException 218 * If the {@code offset} and {@code count} arguments index 219 * characters outside the bounds of the {@code value} array 220 */ 221 public String(char value[], int offset, int count) { 222 if (offset < 0) { 223 throw new StringIndexOutOfBoundsException(offset); 224 } 225 if (count < 0) { 226 throw new StringIndexOutOfBoundsException(count); 227 } 228 // Note: offset or count might be near -1>>>1. 229 if (offset > value.length - count) { 230 throw new StringIndexOutOfBoundsException(offset + count); 231 } 232 this.offset = 0; 233 this.count = count; 234 this.value = Arrays.copyOfRange(value, offset, offset+count); 235 } 236 237 /** 238 * Allocates a new {@code String} that contains characters from a subarray 239 * of the <a href="Character.html#unicode">Unicode code point</a> array 240 * argument. The {@code offset} argument is the index of the first code 241 * point of the subarray and the {@code count} argument specifies the 242 * length of the subarray. The contents of the subarray are converted to 243 * {@code char}s; subsequent modification of the {@code int} array does not 244 * affect the newly created string. 245 * 246 * @param codePoints 247 * Array that is the source of Unicode code points 248 * 249 * @param offset 250 * The initial offset 251 * 252 * @param count 253 * The length 254 * 255 * @throws IllegalArgumentException 256 * If any invalid Unicode code point is found in {@code 257 * codePoints} 258 * 259 * @throws IndexOutOfBoundsException 260 * If the {@code offset} and {@code count} arguments index 261 * characters outside the bounds of the {@code codePoints} array 262 * 263 * @since 1.5 264 */ 265 public String(int[] codePoints, int offset, int count) { 266 if (offset < 0) { 267 throw new StringIndexOutOfBoundsException(offset); 268 } 269 if (count < 0) { 270 throw new StringIndexOutOfBoundsException(count); 271 } 272 // Note: offset or count might be near -1>>>1. 273 if (offset > codePoints.length - count) { 274 throw new StringIndexOutOfBoundsException(offset + count); 275 } 276 277 final int end = offset + count; 278 279 // Pass 1: Compute precise size of char[] 280 int n = count; 281 for (int i = offset; i < end; i++) { 282 int c = codePoints[i]; 283 if (Character.isBmpCodePoint(c)) 284 continue; 285 else if (Character.isValidCodePoint(c)) 286 n++; 287 else throw new IllegalArgumentException(Integer.toString(c)); 288 } 289 290 // Pass 2: Allocate and fill in char[] 291 final char[] v = new char[n]; 292 293 for (int i = offset, j = 0; i < end; i++, j++) { 294 int c = codePoints[i]; 295 if (Character.isBmpCodePoint(c)) 296 v[j] = (char) c; 297 else 298 Character.toSurrogates(c, v, j++); 299 } 300 301 this.value = v; 302 this.count = n; 303 this.offset = 0; 304 } 305 306 /** 307 * Allocates a new {@code String} constructed from a subarray of an array 308 * of 8-bit integer values. 309 * 310 * <p> The {@code offset} argument is the index of the first byte of the 311 * subarray, and the {@code count} argument specifies the length of the 312 * subarray. 313 * 314 * <p> Each {@code byte} in the subarray is converted to a {@code char} as 315 * specified in the method above. 316 * 317 * @deprecated This method does not properly convert bytes into characters. 318 * As of JDK 1.1, the preferred way to do this is via the 319 * {@code String} constructors that take a {@link 320 * java.nio.charset.Charset}, charset name, or that use the platform's 321 * default charset. 322 * 323 * @param ascii 324 * The bytes to be converted to characters 325 * 326 * @param hibyte 327 * The top 8 bits of each 16-bit Unicode code unit 328 * 329 * @param offset 330 * The initial offset 331 * @param count 332 * The length 333 * 334 * @throws IndexOutOfBoundsException 335 * If the {@code offset} or {@code count} argument is invalid 336 * 337 * @see #String(byte[], int) 338 * @see #String(byte[], int, int, java.lang.String) 339 * @see #String(byte[], int, int, java.nio.charset.Charset) 340 * @see #String(byte[], int, int) 341 * @see #String(byte[], java.lang.String) 342 * @see #String(byte[], java.nio.charset.Charset) 343 * @see #String(byte[]) 344 */ 345 @Deprecated 346 public String(byte ascii[], int hibyte, int offset, int count) { 347 checkBounds(ascii, offset, count); 348 char value[] = new char[count]; 349 350 if (hibyte == 0) { 351 for (int i = count ; i-- > 0 ;) { 352 value[i] = (char) (ascii[i + offset] & 0xff); 353 } 354 } else { 355 hibyte <<= 8; 356 for (int i = count ; i-- > 0 ;) { 357 value[i] = (char) (hibyte | (ascii[i + offset] & 0xff)); 358 } 359 } 360 this.offset = 0; 361 this.count = count; 362 this.value = value; 363 } 364 365 /** 366 * Allocates a new {@code String} containing characters constructed from 367 * an array of 8-bit integer values. Each character <i>c</i>in the 368 * resulting string is constructed from the corresponding component 369 * <i>b</i> in the byte array such that: 370 * 371 * <blockquote><pre> 372 * <b><i>c</i></b> == (char)(((hibyte & 0xff) << 8) 373 * | (<b><i>b</i></b> & 0xff)) 374 * </pre></blockquote> 375 * 376 * @deprecated This method does not properly convert bytes into 377 * characters. As of JDK 1.1, the preferred way to do this is via the 378 * {@code String} constructors that take a {@link 379 * java.nio.charset.Charset}, charset name, or that use the platform's 380 * default charset. 381 * 382 * @param ascii 383 * The bytes to be converted to characters 384 * 385 * @param hibyte 386 * The top 8 bits of each 16-bit Unicode code unit 387 * 388 * @see #String(byte[], int, int, java.lang.String) 389 * @see #String(byte[], int, int, java.nio.charset.Charset) 390 * @see #String(byte[], int, int) 391 * @see #String(byte[], java.lang.String) 392 * @see #String(byte[], java.nio.charset.Charset) 393 * @see #String(byte[]) 394 */ 395 @Deprecated 396 public String(byte ascii[], int hibyte) { 397 this(ascii, hibyte, 0, ascii.length); 398 } 399 400 /* Common private utility method used to bounds check the byte array 401 * and requested offset & length values used by the String(byte[],..) 402 * constructors. 403 */ 404 private static void checkBounds(byte[] bytes, int offset, int length) { 405 if (length < 0) 406 throw new StringIndexOutOfBoundsException(length); 407 if (offset < 0) 408 throw new StringIndexOutOfBoundsException(offset); 409 if (offset > bytes.length - length) 410 throw new StringIndexOutOfBoundsException(offset + length); 411 } 412 413 /** 414 * Constructs a new {@code String} by decoding the specified subarray of 415 * bytes using the specified charset. The length of the new {@code String} 416 * is a function of the charset, and hence may not be equal to the length 417 * of the subarray. 418 * 419 * <p> The behavior of this constructor when the given bytes are not valid 420 * in the given charset is unspecified. The {@link 421 * java.nio.charset.CharsetDecoder} class should be used when more control 422 * over the decoding process is required. 423 * 424 * @param bytes 425 * The bytes to be decoded into characters 426 * 427 * @param offset 428 * The index of the first byte to decode 429 * 430 * @param length 431 * The number of bytes to decode 432 433 * @param charsetName 434 * The name of a supported {@linkplain java.nio.charset.Charset 435 * charset} 436 * 437 * @throws UnsupportedEncodingException 438 * If the named charset is not supported 439 * 440 * @throws IndexOutOfBoundsException 441 * If the {@code offset} and {@code length} arguments index 442 * characters outside the bounds of the {@code bytes} array 443 * 444 * @since JDK1.1 445 */ 446 public String(byte bytes[], int offset, int length, String charsetName) 447 throws UnsupportedEncodingException 448 { 449 if (charsetName == null) 450 throw new NullPointerException("charsetName"); 451 checkBounds(bytes, offset, length); 452 char[] v = StringCoding.decode(charsetName, bytes, offset, length); 453 this.offset = 0; 454 this.count = v.length; 455 this.value = v; 456 } 457 458 /** 459 * Constructs a new {@code String} by decoding the specified subarray of 460 * bytes using the specified {@linkplain java.nio.charset.Charset charset}. 461 * The length of the new {@code String} is a function of the charset, and 462 * hence may not be equal to the length of the subarray. 463 * 464 * <p> This method always replaces malformed-input and unmappable-character 465 * sequences with this charset's default replacement string. The {@link 466 * java.nio.charset.CharsetDecoder} class should be used when more control 467 * over the decoding process is required. 468 * 469 * @param bytes 470 * The bytes to be decoded into characters 471 * 472 * @param offset 473 * The index of the first byte to decode 474 * 475 * @param length 476 * The number of bytes to decode 477 * 478 * @param charset 479 * The {@linkplain java.nio.charset.Charset charset} to be used to 480 * decode the {@code bytes} 481 * 482 * @throws IndexOutOfBoundsException 483 * If the {@code offset} and {@code length} arguments index 484 * characters outside the bounds of the {@code bytes} array 485 * 486 * @since 1.6 487 */ 488 public String(byte bytes[], int offset, int length, Charset charset) { 489 if (charset == null) 490 throw new NullPointerException("charset"); 491 checkBounds(bytes, offset, length); 492 char[] v = StringCoding.decode(charset, bytes, offset, length); 493 this.offset = 0; 494 this.count = v.length; 495 this.value = v; 496 } 497 498 /** 499 * Constructs a new {@code String} by decoding the specified array of bytes 500 * using the specified {@linkplain java.nio.charset.Charset charset}. The 501 * length of the new {@code String} is a function of the charset, and hence 502 * may not be equal to the length of the byte array. 503 * 504 * <p> The behavior of this constructor when the given bytes are not valid 505 * in the given charset is unspecified. The {@link 506 * java.nio.charset.CharsetDecoder} class should be used when more control 507 * over the decoding process is required. 508 * 509 * @param bytes 510 * The bytes to be decoded into characters 511 * 512 * @param charsetName 513 * The name of a supported {@linkplain java.nio.charset.Charset 514 * charset} 515 * 516 * @throws UnsupportedEncodingException 517 * If the named charset is not supported 518 * 519 * @since JDK1.1 520 */ 521 public String(byte bytes[], String charsetName) 522 throws UnsupportedEncodingException 523 { 524 this(bytes, 0, bytes.length, charsetName); 525 } 526 527 /** 528 * Constructs a new {@code String} by decoding the specified array of 529 * bytes using the specified {@linkplain java.nio.charset.Charset charset}. 530 * The length of the new {@code String} is a function of the charset, and 531 * hence may not be equal to the length of the byte array. 532 * 533 * <p> This method always replaces malformed-input and unmappable-character 534 * sequences with this charset's default replacement string. The {@link 535 * java.nio.charset.CharsetDecoder} class should be used when more control 536 * over the decoding process is required. 537 * 538 * @param bytes 539 * The bytes to be decoded into characters 540 * 541 * @param charset 542 * The {@linkplain java.nio.charset.Charset charset} to be used to 543 * decode the {@code bytes} 544 * 545 * @since 1.6 546 */ 547 public String(byte bytes[], Charset charset) { 548 this(bytes, 0, bytes.length, charset); 549 } 550 551 /** 552 * Constructs a new {@code String} by decoding the specified subarray of 553 * bytes using the platform's default charset. The length of the new 554 * {@code String} is a function of the charset, and hence may not be equal 555 * to the length of the subarray. 556 * 557 * <p> The behavior of this constructor when the given bytes are not valid 558 * in the default charset is unspecified. The {@link 559 * java.nio.charset.CharsetDecoder} class should be used when more control 560 * over the decoding process is required. 561 * 562 * @param bytes 563 * The bytes to be decoded into characters 564 * 565 * @param offset 566 * The index of the first byte to decode 567 * 568 * @param length 569 * The number of bytes to decode 570 * 571 * @throws IndexOutOfBoundsException 572 * If the {@code offset} and the {@code length} arguments index 573 * characters outside the bounds of the {@code bytes} array 574 * 575 * @since JDK1.1 576 */ 577 public String(byte bytes[], int offset, int length) { 578 checkBounds(bytes, offset, length); 579 char[] v = StringCoding.decode(bytes, offset, length); 580 this.offset = 0; 581 this.count = v.length; 582 this.value = v; 583 } 584 585 /** 586 * Constructs a new {@code String} by decoding the specified array of bytes 587 * using the platform's default charset. The length of the new {@code 588 * String} is a function of the charset, and hence may not be equal to the 589 * length of the byte array. 590 * 591 * <p> The behavior of this constructor when the given bytes are not valid 592 * in the default charset is unspecified. The {@link 593 * java.nio.charset.CharsetDecoder} class should be used when more control 594 * over the decoding process is required. 595 * 596 * @param bytes 597 * The bytes to be decoded into characters 598 * 599 * @since JDK1.1 600 */ 601 public String(byte bytes[]) { 602 this(bytes, 0, bytes.length); 603 } 604 605 /** 606 * Allocates a new string that contains the sequence of characters 607 * currently contained in the string buffer argument. The contents of the 608 * string buffer are copied; subsequent modification of the string buffer 609 * does not affect the newly created string. 610 * 611 * @param buffer 612 * A {@code StringBuffer} 613 */ 614 public String(StringBuffer buffer) { 615 String result = buffer.toString(); 616 this.value = result.value; 617 this.count = result.count; 618 this.offset = result.offset; 619 } 620 621 /** 622 * Allocates a new string that contains the sequence of characters 623 * currently contained in the string builder argument. The contents of the 624 * string builder are copied; subsequent modification of the string builder 625 * does not affect the newly created string. 626 * 627 * <p> This constructor is provided to ease migration to {@code 628 * StringBuilder}. Obtaining a string from a string builder via the {@code 629 * toString} method is likely to run faster and is generally preferred. 630 * 631 * @param builder 632 * A {@code StringBuilder} 633 * 634 * @since 1.5 635 */ 636 public String(StringBuilder builder) { 637 String result = builder.toString(); 638 this.value = result.value; 639 this.count = result.count; 640 this.offset = result.offset; 641 } 642 643 644 // Package private constructor which shares value array for speed. 645 String(int offset, int count, char value[]) { 646 this.value = value; 647 this.offset = offset; 648 this.count = count; 649 } 650 651 /** 652 * Returns the length of this string. 653 * The length is equal to the number of <a href="Character.html#unicode">Unicode 654 * code units</a> in the string. 655 * 656 * @return the length of the sequence of characters represented by this 657 * object. 658 */ 659 public int length() { 660 return count; 661 } 662 663 /** 664 * Returns <tt>true</tt> if, and only if, {@link #length()} is <tt>0</tt>. 665 * 666 * @return <tt>true</tt> if {@link #length()} is <tt>0</tt>, otherwise 667 * <tt>false</tt> 668 * 669 * @since 1.6 670 */ 671 public boolean isEmpty() { 672 return count == 0; 673 } 674 675 /** 676 * Returns the {@code char} value at the 677 * specified index. An index ranges from {@code 0} to 678 * {@code length() - 1}. The first {@code char} value of the sequence 679 * is at index {@code 0}, the next at index {@code 1}, 680 * and so on, as for array indexing. 681 * 682 * <p>If the {@code char} value specified by the index is a 683 * <a href="Character.html#unicode">surrogate</a>, the surrogate 684 * value is returned. 685 * 686 * @param index the index of the {@code char} value. 687 * @return the {@code char} value at the specified index of this string. 688 * The first {@code char} value is at index {@code 0}. 689 * @exception IndexOutOfBoundsException if the {@code index} 690 * argument is negative or not less than the length of this 691 * string. 692 */ 693 public char charAt(int index) { 694 if ((index < 0) || (index >= count)) { 695 throw new StringIndexOutOfBoundsException(index); 696 } 697 return value[index + offset]; 698 } 699 700 /** 701 * Returns the character (Unicode code point) at the specified 702 * index. The index refers to {@code char} values 703 * (Unicode code units) and ranges from {@code 0} to 704 * {@link #length()}{@code - 1}. 705 * 706 * <p> If the {@code char} value specified at the given index 707 * is in the high-surrogate range, the following index is less 708 * than the length of this {@code String}, and the 709 * {@code char} value at the following index is in the 710 * low-surrogate range, then the supplementary code point 711 * corresponding to this surrogate pair is returned. Otherwise, 712 * the {@code char} value at the given index is returned. 713 * 714 * @param index the index to the {@code char} values 715 * @return the code point value of the character at the 716 * {@code index} 717 * @exception IndexOutOfBoundsException if the {@code index} 718 * argument is negative or not less than the length of this 719 * string. 720 * @since 1.5 721 */ 722 public int codePointAt(int index) { 723 if ((index < 0) || (index >= count)) { 724 throw new StringIndexOutOfBoundsException(index); 725 } 726 return Character.codePointAtImpl(value, offset + index, offset + count); 727 } 728 729 /** 730 * Returns the character (Unicode code point) before the specified 731 * index. The index refers to {@code char} values 732 * (Unicode code units) and ranges from {@code 1} to {@link 733 * CharSequence#length() length}. 734 * 735 * <p> If the {@code char} value at {@code (index - 1)} 736 * is in the low-surrogate range, {@code (index - 2)} is not 737 * negative, and the {@code char} value at {@code (index - 738 * 2)} is in the high-surrogate range, then the 739 * supplementary code point value of the surrogate pair is 740 * returned. If the {@code char} value at {@code index - 741 * 1} is an unpaired low-surrogate or a high-surrogate, the 742 * surrogate value is returned. 743 * 744 * @param index the index following the code point that should be returned 745 * @return the Unicode code point value before the given index. 746 * @exception IndexOutOfBoundsException if the {@code index} 747 * argument is less than 1 or greater than the length 748 * of this string. 749 * @since 1.5 750 */ 751 public int codePointBefore(int index) { 752 int i = index - 1; 753 if ((i < 0) || (i >= count)) { 754 throw new StringIndexOutOfBoundsException(index); 755 } 756 return Character.codePointBeforeImpl(value, offset + index, offset); 757 } 758 759 /** 760 * Returns the number of Unicode code points in the specified text 761 * range of this {@code String}. The text range begins at the 762 * specified {@code beginIndex} and extends to the 763 * {@code char} at index {@code endIndex - 1}. Thus the 764 * length (in {@code char}s) of the text range is 765 * {@code endIndex-beginIndex}. Unpaired surrogates within 766 * the text range count as one code point each. 767 * 768 * @param beginIndex the index to the first {@code char} of 769 * the text range. 770 * @param endIndex the index after the last {@code char} of 771 * the text range. 772 * @return the number of Unicode code points in the specified text 773 * range 774 * @exception IndexOutOfBoundsException if the 775 * {@code beginIndex} is negative, or {@code endIndex} 776 * is larger than the length of this {@code String}, or 777 * {@code beginIndex} is larger than {@code endIndex}. 778 * @since 1.5 779 */ 780 public int codePointCount(int beginIndex, int endIndex) { 781 if (beginIndex < 0 || endIndex > count || beginIndex > endIndex) { 782 throw new IndexOutOfBoundsException(); 783 } 784 return Character.codePointCountImpl(value, offset+beginIndex, endIndex-beginIndex); 785 } 786 787 /** 788 * Returns the index within this {@code String} that is 789 * offset from the given {@code index} by 790 * {@code codePointOffset} code points. Unpaired surrogates 791 * within the text range given by {@code index} and 792 * {@code codePointOffset} count as one code point each. 793 * 794 * @param index the index to be offset 795 * @param codePointOffset the offset in code points 796 * @return the index within this {@code String} 797 * @exception IndexOutOfBoundsException if {@code index} 798 * is negative or larger then the length of this 799 * {@code String}, or if {@code codePointOffset} is positive 800 * and the substring starting with {@code index} has fewer 801 * than {@code codePointOffset} code points, 802 * or if {@code codePointOffset} is negative and the substring 803 * before {@code index} has fewer than the absolute value 804 * of {@code codePointOffset} code points. 805 * @since 1.5 806 */ 807 public int offsetByCodePoints(int index, int codePointOffset) { 808 if (index < 0 || index > count) { 809 throw new IndexOutOfBoundsException(); 810 } 811 return Character.offsetByCodePointsImpl(value, offset, count, 812 offset+index, codePointOffset) - offset; 813 } 814 815 /** 816 * Copy characters from this string into dst starting at dstBegin. 817 * This method doesn't perform any range checking. 818 */ 819 void getChars(char dst[], int dstBegin) { 820 System.arraycopy(value, offset, dst, dstBegin, count); 821 } 822 823 /** 824 * Copies characters from this string into the destination character 825 * array. 826 * <p> 827 * The first character to be copied is at index {@code srcBegin}; 828 * the last character to be copied is at index {@code srcEnd-1} 829 * (thus the total number of characters to be copied is 830 * {@code srcEnd-srcBegin}). The characters are copied into the 831 * subarray of {@code dst} starting at index {@code dstBegin} 832 * and ending at index: 833 * <p><blockquote><pre> 834 * dstbegin + (srcEnd-srcBegin) - 1 835 * </pre></blockquote> 836 * 837 * @param srcBegin index of the first character in the string 838 * to copy. 839 * @param srcEnd index after the last character in the string 840 * to copy. 841 * @param dst the destination array. 842 * @param dstBegin the start offset in the destination array. 843 * @exception IndexOutOfBoundsException If any of the following 844 * is true: 845 * <ul><li>{@code srcBegin} is negative. 846 * <li>{@code srcBegin} is greater than {@code srcEnd} 847 * <li>{@code srcEnd} is greater than the length of this 848 * string 849 * <li>{@code dstBegin} is negative 850 * <li>{@code dstBegin+(srcEnd-srcBegin)} is larger than 851 * {@code dst.length}</ul> 852 */ 853 public void getChars(int srcBegin, int srcEnd, char dst[], int dstBegin) { 854 if (srcBegin < 0) { 855 throw new StringIndexOutOfBoundsException(srcBegin); 856 } 857 if (srcEnd > count) { 858 throw new StringIndexOutOfBoundsException(srcEnd); 859 } 860 if (srcBegin > srcEnd) { 861 throw new StringIndexOutOfBoundsException(srcEnd - srcBegin); 862 } 863 System.arraycopy(value, offset + srcBegin, dst, dstBegin, 864 srcEnd - srcBegin); 865 } 866 867 /** 868 * Copies characters from this string into the destination byte array. Each 869 * byte receives the 8 low-order bits of the corresponding character. The 870 * eight high-order bits of each character are not copied and do not 871 * participate in the transfer in any way. 872 * 873 * <p> The first character to be copied is at index {@code srcBegin}; the 874 * last character to be copied is at index {@code srcEnd-1}. The total 875 * number of characters to be copied is {@code srcEnd-srcBegin}. The 876 * characters, converted to bytes, are copied into the subarray of {@code 877 * dst} starting at index {@code dstBegin} and ending at index: 878 * 879 * <blockquote><pre> 880 * dstbegin + (srcEnd-srcBegin) - 1 881 * </pre></blockquote> 882 * 883 * @deprecated This method does not properly convert characters into 884 * bytes. As of JDK 1.1, the preferred way to do this is via the 885 * {@link #getBytes()} method, which uses the platform's default charset. 886 * 887 * @param srcBegin 888 * Index of the first character in the string to copy 889 * 890 * @param srcEnd 891 * Index after the last character in the string to copy 892 * 893 * @param dst 894 * The destination array 895 * 896 * @param dstBegin 897 * The start offset in the destination array 898 * 899 * @throws IndexOutOfBoundsException 900 * If any of the following is true: 901 * <ul> 902 * <li> {@code srcBegin} is negative 903 * <li> {@code srcBegin} is greater than {@code srcEnd} 904 * <li> {@code srcEnd} is greater than the length of this String 905 * <li> {@code dstBegin} is negative 906 * <li> {@code dstBegin+(srcEnd-srcBegin)} is larger than {@code 907 * dst.length} 908 * </ul> 909 */ 910 @Deprecated 911 public void getBytes(int srcBegin, int srcEnd, byte dst[], int dstBegin) { 912 if (srcBegin < 0) { 913 throw new StringIndexOutOfBoundsException(srcBegin); 914 } 915 if (srcEnd > count) { 916 throw new StringIndexOutOfBoundsException(srcEnd); 917 } 918 if (srcBegin > srcEnd) { 919 throw new StringIndexOutOfBoundsException(srcEnd - srcBegin); 920 } 921 int j = dstBegin; 922 int n = offset + srcEnd; 923 int i = offset + srcBegin; 924 char[] val = value; /* avoid getfield opcode */ 925 926 while (i < n) { 927 dst[j++] = (byte)val[i++]; 928 } 929 } 930 931 /** 932 * Encodes this {@code String} into a sequence of bytes using the named 933 * charset, storing the result into a new byte array. 934 * 935 * <p> The behavior of this method when this string cannot be encoded in 936 * the given charset is unspecified. The {@link 937 * java.nio.charset.CharsetEncoder} class should be used when more control 938 * over the encoding process is required. 939 * 940 * @param charsetName 941 * The name of a supported {@linkplain java.nio.charset.Charset 942 * charset} 943 * 944 * @return The resultant byte array 945 * 946 * @throws UnsupportedEncodingException 947 * If the named charset is not supported 948 * 949 * @since JDK1.1 950 */ 951 public byte[] getBytes(String charsetName) 952 throws UnsupportedEncodingException 953 { 954 if (charsetName == null) throw new NullPointerException(); 955 return StringCoding.encode(charsetName, value, offset, count); 956 } 957 958 /** 959 * Encodes this {@code String} into a sequence of bytes using the given 960 * {@linkplain java.nio.charset.Charset charset}, storing the result into a 961 * new byte array. 962 * 963 * <p> This method always replaces malformed-input and unmappable-character 964 * sequences with this charset's default replacement byte array. The 965 * {@link java.nio.charset.CharsetEncoder} class should be used when more 966 * control over the encoding process is required. 967 * 968 * @param charset 969 * The {@linkplain java.nio.charset.Charset} to be used to encode 970 * the {@code String} 971 * 972 * @return The resultant byte array 973 * 974 * @since 1.6 975 */ 976 public byte[] getBytes(Charset charset) { 977 if (charset == null) throw new NullPointerException(); 978 return StringCoding.encode(charset, value, offset, count); 979 } 980 981 /** 982 * Encodes this {@code String} into a sequence of bytes using the 983 * platform's default charset, storing the result into a new byte array. 984 * 985 * <p> The behavior of this method when this string cannot be encoded in 986 * the default charset is unspecified. The {@link 987 * java.nio.charset.CharsetEncoder} class should be used when more control 988 * over the encoding process is required. 989 * 990 * @return The resultant byte array 991 * 992 * @since JDK1.1 993 */ 994 public byte[] getBytes() { 995 return StringCoding.encode(value, offset, count); 996 } 997 998 /** 999 * Compares this string to the specified object. The result is {@code 1000 * true} if and only if the argument is not {@code null} and is a {@code 1001 * String} object that represents the same sequence of characters as this 1002 * object. 1003 * 1004 * @param anObject 1005 * The object to compare this {@code String} against 1006 * 1007 * @return {@code true} if the given object represents a {@code String} 1008 * equivalent to this string, {@code false} otherwise 1009 * 1010 * @see #compareTo(String) 1011 * @see #equalsIgnoreCase(String) 1012 */ 1013 public boolean equals(Object anObject) { 1014 if (this == anObject) { 1015 return true; 1016 } 1017 if (anObject instanceof String) { 1018 String anotherString = (String)anObject; 1019 int n = count; 1020 if (n == anotherString.count) { 1021 char v1[] = value; 1022 char v2[] = anotherString.value; 1023 int i = offset; 1024 int j = anotherString.offset; 1025 while (n-- != 0) { 1026 if (v1[i++] != v2[j++]) 1027 return false; 1028 } 1029 return true; 1030 } 1031 } 1032 return false; 1033 } 1034 1035 /** 1036 * Compares this string to the specified {@code StringBuffer}. The result 1037 * is {@code true} if and only if this {@code String} represents the same 1038 * sequence of characters as the specified {@code StringBuffer}. 1039 * 1040 * @param sb 1041 * The {@code StringBuffer} to compare this {@code String} against 1042 * 1043 * @return {@code true} if this {@code String} represents the same 1044 * sequence of characters as the specified {@code StringBuffer}, 1045 * {@code false} otherwise 1046 * 1047 * @since 1.4 1048 */ 1049 public boolean contentEquals(StringBuffer sb) { 1050 synchronized(sb) { 1051 return contentEquals((CharSequence)sb); 1052 } 1053 } 1054 1055 /** 1056 * Compares this string to the specified {@code CharSequence}. The result 1057 * is {@code true} if and only if this {@code String} represents the same 1058 * sequence of char values as the specified sequence. 1059 * 1060 * @param cs 1061 * The sequence to compare this {@code String} against 1062 * 1063 * @return {@code true} if this {@code String} represents the same 1064 * sequence of char values as the specified sequence, {@code 1065 * false} otherwise 1066 * 1067 * @since 1.5 1068 */ 1069 public boolean contentEquals(CharSequence cs) { 1070 if (count != cs.length()) 1071 return false; 1072 // Argument is a StringBuffer, StringBuilder 1073 if (cs instanceof AbstractStringBuilder) { 1074 char v1[] = value; 1075 char v2[] = ((AbstractStringBuilder)cs).getValue(); 1076 int i = offset; 1077 int j = 0; 1078 int n = count; 1079 while (n-- != 0) { 1080 if (v1[i++] != v2[j++]) 1081 return false; 1082 } 1083 return true; 1084 } 1085 // Argument is a String 1086 if (cs.equals(this)) 1087 return true; 1088 // Argument is a generic CharSequence 1089 char v1[] = value; 1090 int i = offset; 1091 int j = 0; 1092 int n = count; 1093 while (n-- != 0) { 1094 if (v1[i++] != cs.charAt(j++)) 1095 return false; 1096 } 1097 return true; 1098 } 1099 1100 /** 1101 * Compares this {@code String} to another {@code String}, ignoring case 1102 * considerations. Two strings are considered equal ignoring case if they 1103 * are of the same length and corresponding characters in the two strings 1104 * are equal ignoring case. 1105 * 1106 * <p> Two characters {@code c1} and {@code c2} are considered the same 1107 * ignoring case if at least one of the following is true: 1108 * <ul> 1109 * <li> The two characters are the same (as compared by the 1110 * {@code ==} operator) 1111 * <li> Applying the method {@link 1112 * java.lang.Character#toUpperCase(char)} to each character 1113 * produces the same result 1114 * <li> Applying the method {@link 1115 * java.lang.Character#toLowerCase(char)} to each character 1116 * produces the same result 1117 * </ul> 1118 * 1119 * @param anotherString 1120 * The {@code String} to compare this {@code String} against 1121 * 1122 * @return {@code true} if the argument is not {@code null} and it 1123 * represents an equivalent {@code String} ignoring case; {@code 1124 * false} otherwise 1125 * 1126 * @see #equals(Object) 1127 */ 1128 public boolean equalsIgnoreCase(String anotherString) { 1129 return (this == anotherString) ? true : 1130 (anotherString != null) && (anotherString.count == count) && 1131 regionMatches(true, 0, anotherString, 0, count); 1132 } 1133 1134 /** 1135 * Compares two strings lexicographically. 1136 * The comparison is based on the Unicode value of each character in 1137 * the strings. The character sequence represented by this 1138 * {@code String} object is compared lexicographically to the 1139 * character sequence represented by the argument string. The result is 1140 * a negative integer if this {@code String} object 1141 * lexicographically precedes the argument string. The result is a 1142 * positive integer if this {@code String} object lexicographically 1143 * follows the argument string. The result is zero if the strings 1144 * are equal; {@code compareTo} returns {@code 0} exactly when 1145 * the {@link #equals(Object)} method would return {@code true}. 1146 * <p> 1147 * This is the definition of lexicographic ordering. If two strings are 1148 * different, then either they have different characters at some index 1149 * that is a valid index for both strings, or their lengths are different, 1150 * or both. If they have different characters at one or more index 1151 * positions, let <i>k</i> be the smallest such index; then the string 1152 * whose character at position <i>k</i> has the smaller value, as 1153 * determined by using the < operator, lexicographically precedes the 1154 * other string. In this case, {@code compareTo} returns the 1155 * difference of the two character values at position {@code k} in 1156 * the two string -- that is, the value: 1157 * <blockquote><pre> 1158 * this.charAt(k)-anotherString.charAt(k) 1159 * </pre></blockquote> 1160 * If there is no index position at which they differ, then the shorter 1161 * string lexicographically precedes the longer string. In this case, 1162 * {@code compareTo} returns the difference of the lengths of the 1163 * strings -- that is, the value: 1164 * <blockquote><pre> 1165 * this.length()-anotherString.length() 1166 * </pre></blockquote> 1167 * 1168 * @param anotherString the {@code String} to be compared. 1169 * @return the value {@code 0} if the argument string is equal to 1170 * this string; a value less than {@code 0} if this string 1171 * is lexicographically less than the string argument; and a 1172 * value greater than {@code 0} if this string is 1173 * lexicographically greater than the string argument. 1174 */ 1175 public int compareTo(String anotherString) { 1176 int len1 = count; 1177 int len2 = anotherString.count; 1178 int n = Math.min(len1, len2); 1179 char v1[] = value; 1180 char v2[] = anotherString.value; 1181 int i = offset; 1182 int j = anotherString.offset; 1183 1184 if (i == j) { 1185 int k = i; 1186 int lim = n + i; 1187 while (k < lim) { 1188 char c1 = v1[k]; 1189 char c2 = v2[k]; 1190 if (c1 != c2) { 1191 return c1 - c2; 1192 } 1193 k++; 1194 } 1195 } else { 1196 while (n-- != 0) { 1197 char c1 = v1[i++]; 1198 char c2 = v2[j++]; 1199 if (c1 != c2) { 1200 return c1 - c2; 1201 } 1202 } 1203 } 1204 return len1 - len2; 1205 } 1206 1207 /** 1208 * A Comparator that orders {@code String} objects as by 1209 * {@code compareToIgnoreCase}. This comparator is serializable. 1210 * <p> 1211 * Note that this Comparator does <em>not</em> take locale into account, 1212 * and will result in an unsatisfactory ordering for certain locales. 1213 * The java.text package provides <em>Collators</em> to allow 1214 * locale-sensitive ordering. 1215 * 1216 * @see java.text.Collator#compare(String, String) 1217 * @since 1.2 1218 */ 1219 public static final Comparator<String> CASE_INSENSITIVE_ORDER 1220 = new CaseInsensitiveComparator(); 1221 private static class CaseInsensitiveComparator 1222 implements Comparator<String>, java.io.Serializable { 1223 // use serialVersionUID from JDK 1.2.2 for interoperability 1224 private static final long serialVersionUID = 8575799808933029326L; 1225 1226 public int compare(String s1, String s2) { 1227 int n1 = s1.length(); 1228 int n2 = s2.length(); 1229 int min = Math.min(n1, n2); 1230 for (int i = 0; i < min; i++) { 1231 char c1 = s1.charAt(i); 1232 char c2 = s2.charAt(i); 1233 if (c1 != c2) { 1234 c1 = Character.toUpperCase(c1); 1235 c2 = Character.toUpperCase(c2); 1236 if (c1 != c2) { 1237 c1 = Character.toLowerCase(c1); 1238 c2 = Character.toLowerCase(c2); 1239 if (c1 != c2) { 1240 // No overflow because of numeric promotion 1241 return c1 - c2; 1242 } 1243 } 1244 } 1245 } 1246 return n1 - n2; 1247 } 1248 1249 /** Replaces the de-serialized object. */ 1250 private Object readResolve() { return CASE_INSENSITIVE_ORDER; } 1251 } 1252 1253 /** 1254 * Compares two strings lexicographically, ignoring case 1255 * differences. This method returns an integer whose sign is that of 1256 * calling {@code compareTo} with normalized versions of the strings 1257 * where case differences have been eliminated by calling 1258 * {@code Character.toLowerCase(Character.toUpperCase(character))} on 1259 * each character. 1260 * <p> 1261 * Note that this method does <em>not</em> take locale into account, 1262 * and will result in an unsatisfactory ordering for certain locales. 1263 * The java.text package provides <em>collators</em> to allow 1264 * locale-sensitive ordering. 1265 * 1266 * @param str the {@code String} to be compared. 1267 * @return a negative integer, zero, or a positive integer as the 1268 * specified String is greater than, equal to, or less 1269 * than this String, ignoring case considerations. 1270 * @see java.text.Collator#compare(String, String) 1271 * @since 1.2 1272 */ 1273 public int compareToIgnoreCase(String str) { 1274 return CASE_INSENSITIVE_ORDER.compare(this, str); 1275 } 1276 1277 /** 1278 * Tests if two string regions are equal. 1279 * <p> 1280 * A substring of this <tt>String</tt> object is compared to a substring 1281 * of the argument other. The result is true if these substrings 1282 * represent identical character sequences. The substring of this 1283 * <tt>String</tt> object to be compared begins at index <tt>toffset</tt> 1284 * and has length <tt>len</tt>. The substring of other to be compared 1285 * begins at index <tt>ooffset</tt> and has length <tt>len</tt>. The 1286 * result is <tt>false</tt> if and only if at least one of the following 1287 * is true: 1288 * <ul><li><tt>toffset</tt> is negative. 1289 * <li><tt>ooffset</tt> is negative. 1290 * <li><tt>toffset+len</tt> is greater than the length of this 1291 * <tt>String</tt> object. 1292 * <li><tt>ooffset+len</tt> is greater than the length of the other 1293 * argument. 1294 * <li>There is some nonnegative integer <i>k</i> less than <tt>len</tt> 1295 * such that: 1296 * <tt>this.charAt(toffset+<i>k</i>) != other.charAt(ooffset+<i>k</i>)</tt> 1297 * </ul> 1298 * 1299 * @param toffset the starting offset of the subregion in this string. 1300 * @param other the string argument. 1301 * @param ooffset the starting offset of the subregion in the string 1302 * argument. 1303 * @param len the number of characters to compare. 1304 * @return {@code true} if the specified subregion of this string 1305 * exactly matches the specified subregion of the string argument; 1306 * {@code false} otherwise. 1307 */ 1308 public boolean regionMatches(int toffset, String other, int ooffset, 1309 int len) { 1310 char ta[] = value; 1311 int to = offset + toffset; 1312 char pa[] = other.value; 1313 int po = other.offset + ooffset; 1314 // Note: toffset, ooffset, or len might be near -1>>>1. 1315 if ((ooffset < 0) || (toffset < 0) || (toffset > (long)count - len) 1316 || (ooffset > (long)other.count - len)) { 1317 return false; 1318 } 1319 while (len-- > 0) { 1320 if (ta[to++] != pa[po++]) { 1321 return false; 1322 } 1323 } 1324 return true; 1325 } 1326 1327 /** 1328 * Tests if two string regions are equal. 1329 * <p> 1330 * A substring of this <tt>String</tt> object is compared to a substring 1331 * of the argument <tt>other</tt>. The result is <tt>true</tt> if these 1332 * substrings represent character sequences that are the same, ignoring 1333 * case if and only if <tt>ignoreCase</tt> is true. The substring of 1334 * this <tt>String</tt> object to be compared begins at index 1335 * <tt>toffset</tt> and has length <tt>len</tt>. The substring of 1336 * <tt>other</tt> to be compared begins at index <tt>ooffset</tt> and 1337 * has length <tt>len</tt>. The result is <tt>false</tt> if and only if 1338 * at least one of the following is true: 1339 * <ul><li><tt>toffset</tt> is negative. 1340 * <li><tt>ooffset</tt> is negative. 1341 * <li><tt>toffset+len</tt> is greater than the length of this 1342 * <tt>String</tt> object. 1343 * <li><tt>ooffset+len</tt> is greater than the length of the other 1344 * argument. 1345 * <li><tt>ignoreCase</tt> is <tt>false</tt> and there is some nonnegative 1346 * integer <i>k</i> less than <tt>len</tt> such that: 1347 * <blockquote><pre> 1348 * this.charAt(toffset+k) != other.charAt(ooffset+k) 1349 * </pre></blockquote> 1350 * <li><tt>ignoreCase</tt> is <tt>true</tt> and there is some nonnegative 1351 * integer <i>k</i> less than <tt>len</tt> such that: 1352 * <blockquote><pre> 1353 * Character.toLowerCase(this.charAt(toffset+k)) != 1354 Character.toLowerCase(other.charAt(ooffset+k)) 1355 * </pre></blockquote> 1356 * and: 1357 * <blockquote><pre> 1358 * Character.toUpperCase(this.charAt(toffset+k)) != 1359 * Character.toUpperCase(other.charAt(ooffset+k)) 1360 * </pre></blockquote> 1361 * </ul> 1362 * 1363 * @param ignoreCase if {@code true}, ignore case when comparing 1364 * characters. 1365 * @param toffset the starting offset of the subregion in this 1366 * string. 1367 * @param other the string argument. 1368 * @param ooffset the starting offset of the subregion in the string 1369 * argument. 1370 * @param len the number of characters to compare. 1371 * @return {@code true} if the specified subregion of this string 1372 * matches the specified subregion of the string argument; 1373 * {@code false} otherwise. Whether the matching is exact 1374 * or case insensitive depends on the {@code ignoreCase} 1375 * argument. 1376 */ 1377 public boolean regionMatches(boolean ignoreCase, int toffset, 1378 String other, int ooffset, int len) { 1379 char ta[] = value; 1380 int to = offset + toffset; 1381 char pa[] = other.value; 1382 int po = other.offset + ooffset; 1383 // Note: toffset, ooffset, or len might be near -1>>>1. 1384 if ((ooffset < 0) || (toffset < 0) || (toffset > (long)count - len) || 1385 (ooffset > (long)other.count - len)) { 1386 return false; 1387 } 1388 while (len-- > 0) { 1389 char c1 = ta[to++]; 1390 char c2 = pa[po++]; 1391 if (c1 == c2) { 1392 continue; 1393 } 1394 if (ignoreCase) { 1395 // If characters don't match but case may be ignored, 1396 // try converting both characters to uppercase. 1397 // If the results match, then the comparison scan should 1398 // continue. 1399 char u1 = Character.toUpperCase(c1); 1400 char u2 = Character.toUpperCase(c2); 1401 if (u1 == u2) { 1402 continue; 1403 } 1404 // Unfortunately, conversion to uppercase does not work properly 1405 // for the Georgian alphabet, which has strange rules about case 1406 // conversion. So we need to make one last check before 1407 // exiting. 1408 if (Character.toLowerCase(u1) == Character.toLowerCase(u2)) { 1409 continue; 1410 } 1411 } 1412 return false; 1413 } 1414 return true; 1415 } 1416 1417 /** 1418 * Tests if the substring of this string beginning at the 1419 * specified index starts with the specified prefix. 1420 * 1421 * @param prefix the prefix. 1422 * @param toffset where to begin looking in this string. 1423 * @return {@code true} if the character sequence represented by the 1424 * argument is a prefix of the substring of this object starting 1425 * at index {@code toffset}; {@code false} otherwise. 1426 * The result is {@code false} if {@code toffset} is 1427 * negative or greater than the length of this 1428 * {@code String} object; otherwise the result is the same 1429 * as the result of the expression 1430 * <pre> 1431 * this.substring(toffset).startsWith(prefix) 1432 * </pre> 1433 */ 1434 public boolean startsWith(String prefix, int toffset) { 1435 char ta[] = value; 1436 int to = offset + toffset; 1437 char pa[] = prefix.value; 1438 int po = prefix.offset; 1439 int pc = prefix.count; 1440 // Note: toffset might be near -1>>>1. 1441 if ((toffset < 0) || (toffset > count - pc)) { 1442 return false; 1443 } 1444 while (--pc >= 0) { 1445 if (ta[to++] != pa[po++]) { 1446 return false; 1447 } 1448 } 1449 return true; 1450 } 1451 1452 /** 1453 * Tests if this string starts with the specified prefix. 1454 * 1455 * @param prefix the prefix. 1456 * @return {@code true} if the character sequence represented by the 1457 * argument is a prefix of the character sequence represented by 1458 * this string; {@code false} otherwise. 1459 * Note also that {@code true} will be returned if the 1460 * argument is an empty string or is equal to this 1461 * {@code String} object as determined by the 1462 * {@link #equals(Object)} method. 1463 * @since 1. 0 1464 */ 1465 public boolean startsWith(String prefix) { 1466 return startsWith(prefix, 0); 1467 } 1468 1469 /** 1470 * Tests if this string ends with the specified suffix. 1471 * 1472 * @param suffix the suffix. 1473 * @return {@code true} if the character sequence represented by the 1474 * argument is a suffix of the character sequence represented by 1475 * this object; {@code false} otherwise. Note that the 1476 * result will be {@code true} if the argument is the 1477 * empty string or is equal to this {@code String} object 1478 * as determined by the {@link #equals(Object)} method. 1479 */ 1480 public boolean endsWith(String suffix) { 1481 return startsWith(suffix, count - suffix.count); 1482 } 1483 1484 /** 1485 * Returns a hash code for this string. The hash code for a 1486 * {@code String} object is computed as 1487 * <blockquote><pre> 1488 * s[0]*31^(n-1) + s[1]*31^(n-2) + ... + s[n-1] 1489 * </pre></blockquote> 1490 * using {@code int} arithmetic, where {@code s[i]} is the 1491 * <i>i</i>th character of the string, {@code n} is the length of 1492 * the string, and {@code ^} indicates exponentiation. 1493 * (The hash value of the empty string is zero.) 1494 * 1495 * @return a hash code value for this object. 1496 */ 1497 public int hashCode() { 1498 int h = hash; 1499 if (h == 0 && count > 0) { 1500 int off = offset; 1501 char val[] = value; 1502 int len = count; 1503 1504 for (int i = 0; i < len; i++) { 1505 h = 31*h + val[off++]; 1506 } 1507 hash = h; 1508 } 1509 return h; 1510 } 1511 1512 /** 1513 * Returns the index within this string of the first occurrence of 1514 * the specified character. If a character with value 1515 * {@code ch} occurs in the character sequence represented by 1516 * this {@code String} object, then the index (in Unicode 1517 * code units) of the first such occurrence is returned. For 1518 * values of {@code ch} in the range from 0 to 0xFFFF 1519 * (inclusive), this is the smallest value <i>k</i> such that: 1520 * <blockquote><pre> 1521 * this.charAt(<i>k</i>) == ch 1522 * </pre></blockquote> 1523 * is true. For other values of {@code ch}, it is the 1524 * smallest value <i>k</i> such that: 1525 * <blockquote><pre> 1526 * this.codePointAt(<i>k</i>) == ch 1527 * </pre></blockquote> 1528 * is true. In either case, if no such character occurs in this 1529 * string, then {@code -1} is returned. 1530 * 1531 * @param ch a character (Unicode code point). 1532 * @return the index of the first occurrence of the character in the 1533 * character sequence represented by this object, or 1534 * {@code -1} if the character does not occur. 1535 */ 1536 public int indexOf(int ch) { 1537 return indexOf(ch, 0); 1538 } 1539 1540 /** 1541 * Returns the index within this string of the first occurrence of the 1542 * specified character, starting the search at the specified index. 1543 * <p> 1544 * If a character with value {@code ch} occurs in the 1545 * character sequence represented by this {@code String} 1546 * object at an index no smaller than {@code fromIndex}, then 1547 * the index of the first such occurrence is returned. For values 1548 * of {@code ch} in the range from 0 to 0xFFFF (inclusive), 1549 * this is the smallest value <i>k</i> such that: 1550 * <blockquote><pre> 1551 * (this.charAt(<i>k</i>) == ch) && (<i>k</i> >= fromIndex) 1552 * </pre></blockquote> 1553 * is true. For other values of {@code ch}, it is the 1554 * smallest value <i>k</i> such that: 1555 * <blockquote><pre> 1556 * (this.codePointAt(<i>k</i>) == ch) && (<i>k</i> >= fromIndex) 1557 * </pre></blockquote> 1558 * is true. In either case, if no such character occurs in this 1559 * string at or after position {@code fromIndex}, then 1560 * {@code -1} is returned. 1561 * 1562 * <p> 1563 * There is no restriction on the value of {@code fromIndex}. If it 1564 * is negative, it has the same effect as if it were zero: this entire 1565 * string may be searched. If it is greater than the length of this 1566 * string, it has the same effect as if it were equal to the length of 1567 * this string: {@code -1} is returned. 1568 * 1569 * <p>All indices are specified in {@code char} values 1570 * (Unicode code units). 1571 * 1572 * @param ch a character (Unicode code point). 1573 * @param fromIndex the index to start the search from. 1574 * @return the index of the first occurrence of the character in the 1575 * character sequence represented by this object that is greater 1576 * than or equal to {@code fromIndex}, or {@code -1} 1577 * if the character does not occur. 1578 */ 1579 public int indexOf(int ch, int fromIndex) { 1580 if (fromIndex < 0) { 1581 fromIndex = 0; 1582 } else if (fromIndex >= count) { 1583 // Note: fromIndex might be near -1>>>1. 1584 return -1; 1585 } 1586 1587 if (ch < Character.MIN_SUPPLEMENTARY_CODE_POINT) { 1588 // handle most cases here (ch is a BMP code point or a 1589 // negative value (invalid code point)) 1590 final char[] value = this.value; 1591 final int offset = this.offset; 1592 final int max = offset + count; 1593 for (int i = offset + fromIndex; i < max ; i++) { 1594 if (value[i] == ch) { 1595 return i - offset; 1596 } 1597 } 1598 return -1; 1599 } else { 1600 return indexOfSupplementary(ch, fromIndex); 1601 } 1602 } 1603 1604 /** 1605 * Handles (rare) calls of indexOf with a supplementary character. 1606 */ 1607 private int indexOfSupplementary(int ch, int fromIndex) { 1608 if (Character.isValidCodePoint(ch)) { 1609 final char[] value = this.value; 1610 final int offset = this.offset; 1611 final char hi = Character.highSurrogate(ch); 1612 final char lo = Character.lowSurrogate(ch); 1613 final int max = offset + count - 1; 1614 for (int i = offset + fromIndex; i < max; i++) { 1615 if (value[i] == hi && value[i+1] == lo) { 1616 return i - offset; 1617 } 1618 } 1619 } 1620 return -1; 1621 } 1622 1623 /** 1624 * Returns the index within this string of the last occurrence of 1625 * the specified character. For values of {@code ch} in the 1626 * range from 0 to 0xFFFF (inclusive), the index (in Unicode code 1627 * units) returned is the largest value <i>k</i> such that: 1628 * <blockquote><pre> 1629 * this.charAt(<i>k</i>) == ch 1630 * </pre></blockquote> 1631 * is true. For other values of {@code ch}, it is the 1632 * largest value <i>k</i> such that: 1633 * <blockquote><pre> 1634 * this.codePointAt(<i>k</i>) == ch 1635 * </pre></blockquote> 1636 * is true. In either case, if no such character occurs in this 1637 * string, then {@code -1} is returned. The 1638 * {@code String} is searched backwards starting at the last 1639 * character. 1640 * 1641 * @param ch a character (Unicode code point). 1642 * @return the index of the last occurrence of the character in the 1643 * character sequence represented by this object, or 1644 * {@code -1} if the character does not occur. 1645 */ 1646 public int lastIndexOf(int ch) { 1647 return lastIndexOf(ch, count - 1); 1648 } 1649 1650 /** 1651 * Returns the index within this string of the last occurrence of 1652 * the specified character, searching backward starting at the 1653 * specified index. For values of {@code ch} in the range 1654 * from 0 to 0xFFFF (inclusive), the index returned is the largest 1655 * value <i>k</i> such that: 1656 * <blockquote><pre> 1657 * (this.charAt(<i>k</i>) == ch) && (<i>k</i> <= fromIndex) 1658 * </pre></blockquote> 1659 * is true. For other values of {@code ch}, it is the 1660 * largest value <i>k</i> such that: 1661 * <blockquote><pre> 1662 * (this.codePointAt(<i>k</i>) == ch) && (<i>k</i> <= fromIndex) 1663 * </pre></blockquote> 1664 * is true. In either case, if no such character occurs in this 1665 * string at or before position {@code fromIndex}, then 1666 * {@code -1} is returned. 1667 * 1668 * <p>All indices are specified in {@code char} values 1669 * (Unicode code units). 1670 * 1671 * @param ch a character (Unicode code point). 1672 * @param fromIndex the index to start the search from. There is no 1673 * restriction on the value of {@code fromIndex}. If it is 1674 * greater than or equal to the length of this string, it has 1675 * the same effect as if it were equal to one less than the 1676 * length of this string: this entire string may be searched. 1677 * If it is negative, it has the same effect as if it were -1: 1678 * -1 is returned. 1679 * @return the index of the last occurrence of the character in the 1680 * character sequence represented by this object that is less 1681 * than or equal to {@code fromIndex}, or {@code -1} 1682 * if the character does not occur before that point. 1683 */ 1684 public int lastIndexOf(int ch, int fromIndex) { 1685 if (ch < Character.MIN_SUPPLEMENTARY_CODE_POINT) { 1686 // handle most cases here (ch is a BMP code point or a 1687 // negative value (invalid code point)) 1688 final char[] value = this.value; 1689 final int offset = this.offset; 1690 int i = offset + Math.min(fromIndex, count - 1); 1691 for (; i >= offset ; i--) { 1692 if (value[i] == ch) { 1693 return i - offset; 1694 } 1695 } 1696 return -1; 1697 } else { 1698 return lastIndexOfSupplementary(ch, fromIndex); 1699 } 1700 } 1701 1702 /** 1703 * Handles (rare) calls of lastIndexOf with a supplementary character. 1704 */ 1705 private int lastIndexOfSupplementary(int ch, int fromIndex) { 1706 if (Character.isValidCodePoint(ch)) { 1707 final char[] value = this.value; 1708 final int offset = this.offset; 1709 char hi = Character.highSurrogate(ch); 1710 char lo = Character.lowSurrogate(ch); 1711 int i = offset + Math.min(fromIndex, count - 2); 1712 for (; i >= offset; i--) { 1713 if (value[i] == hi && value[i+1] == lo) { 1714 return i - offset; 1715 } 1716 } 1717 } 1718 return -1; 1719 } 1720 1721 /** 1722 * Returns the index within this string of the first occurrence of the 1723 * specified substring. 1724 * 1725 * <p>The returned index is the smallest value <i>k</i> for which: 1726 * <blockquote><pre> 1727 * this.startsWith(str, <i>k</i>) 1728 * </pre></blockquote> 1729 * If no such value of <i>k</i> exists, then {@code -1} is returned. 1730 * 1731 * @param str the substring to search for. 1732 * @return the index of the first occurrence of the specified substring, 1733 * or {@code -1} if there is no such occurrence. 1734 */ 1735 public int indexOf(String str) { 1736 return indexOf(str, 0); 1737 } 1738 1739 /** 1740 * Returns the index within this string of the first occurrence of the 1741 * specified substring, starting at the specified index. 1742 * 1743 * <p>The returned index is the smallest value <i>k</i> for which: 1744 * <blockquote><pre> 1745 * <i>k</i> >= fromIndex && this.startsWith(str, <i>k</i>) 1746 * </pre></blockquote> 1747 * If no such value of <i>k</i> exists, then {@code -1} is returned. 1748 * 1749 * @param str the substring to search for. 1750 * @param fromIndex the index from which to start the search. 1751 * @return the index of the first occurrence of the specified substring, 1752 * starting at the specified index, 1753 * or {@code -1} if there is no such occurrence. 1754 */ 1755 public int indexOf(String str, int fromIndex) { 1756 return indexOf(value, offset, count, 1757 str.value, str.offset, str.count, fromIndex); 1758 } 1759 1760 /** 1761 * Code shared by String and StringBuffer to do searches. The 1762 * source is the character array being searched, and the target 1763 * is the string being searched for. 1764 * 1765 * @param source the characters being searched. 1766 * @param sourceOffset offset of the source string. 1767 * @param sourceCount count of the source string. 1768 * @param target the characters being searched for. 1769 * @param targetOffset offset of the target string. 1770 * @param targetCount count of the target string. 1771 * @param fromIndex the index to begin searching from. 1772 */ 1773 static int indexOf(char[] source, int sourceOffset, int sourceCount, 1774 char[] target, int targetOffset, int targetCount, 1775 int fromIndex) { 1776 if (fromIndex >= sourceCount) { 1777 return (targetCount == 0 ? sourceCount : -1); 1778 } 1779 if (fromIndex < 0) { 1780 fromIndex = 0; 1781 } 1782 if (targetCount == 0) { 1783 return fromIndex; 1784 } 1785 1786 char first = target[targetOffset]; 1787 int max = sourceOffset + (sourceCount - targetCount); 1788 1789 for (int i = sourceOffset + fromIndex; i <= max; i++) { 1790 /* Look for first character. */ 1791 if (source[i] != first) { 1792 while (++i <= max && source[i] != first); 1793 } 1794 1795 /* Found first character, now look at the rest of v2 */ 1796 if (i <= max) { 1797 int j = i + 1; 1798 int end = j + targetCount - 1; 1799 for (int k = targetOffset + 1; j < end && source[j] == 1800 target[k]; j++, k++); 1801 1802 if (j == end) { 1803 /* Found whole string. */ 1804 return i - sourceOffset; 1805 } 1806 } 1807 } 1808 return -1; 1809 } 1810 1811 /** 1812 * Returns the index within this string of the last occurrence of the 1813 * specified substring. The last occurrence of the empty string "" 1814 * is considered to occur at the index value {@code this.length()}. 1815 * 1816 * <p>The returned index is the largest value <i>k</i> for which: 1817 * <blockquote><pre> 1818 * this.startsWith(str, <i>k</i>) 1819 * </pre></blockquote> 1820 * If no such value of <i>k</i> exists, then {@code -1} is returned. 1821 * 1822 * @param str the substring to search for. 1823 * @return the index of the last occurrence of the specified substring, 1824 * or {@code -1} if there is no such occurrence. 1825 */ 1826 public int lastIndexOf(String str) { 1827 return lastIndexOf(str, count); 1828 } 1829 1830 /** 1831 * Returns the index within this string of the last occurrence of the 1832 * specified substring, searching backward starting at the specified index. 1833 * 1834 * <p>The returned index is the largest value <i>k</i> for which: 1835 * <blockquote><pre> 1836 * <i>k</i> <= fromIndex && this.startsWith(str, <i>k</i>) 1837 * </pre></blockquote> 1838 * If no such value of <i>k</i> exists, then {@code -1} is returned. 1839 * 1840 * @param str the substring to search for. 1841 * @param fromIndex the index to start the search from. 1842 * @return the index of the last occurrence of the specified substring, 1843 * searching backward from the specified index, 1844 * or {@code -1} if there is no such occurrence. 1845 */ 1846 public int lastIndexOf(String str, int fromIndex) { 1847 return lastIndexOf(value, offset, count, 1848 str.value, str.offset, str.count, fromIndex); 1849 } 1850 1851 /** 1852 * Code shared by String and StringBuffer to do searches. The 1853 * source is the character array being searched, and the target 1854 * is the string being searched for. 1855 * 1856 * @param source the characters being searched. 1857 * @param sourceOffset offset of the source string. 1858 * @param sourceCount count of the source string. 1859 * @param target the characters being searched for. 1860 * @param targetOffset offset of the target string. 1861 * @param targetCount count of the target string. 1862 * @param fromIndex the index to begin searching from. 1863 */ 1864 static int lastIndexOf(char[] source, int sourceOffset, int sourceCount, 1865 char[] target, int targetOffset, int targetCount, 1866 int fromIndex) { 1867 /* 1868 * Check arguments; return immediately where possible. For 1869 * consistency, don't check for null str. 1870 */ 1871 int rightIndex = sourceCount - targetCount; 1872 if (fromIndex < 0) { 1873 return -1; 1874 } 1875 if (fromIndex > rightIndex) { 1876 fromIndex = rightIndex; 1877 } 1878 /* Empty string always matches. */ 1879 if (targetCount == 0) { 1880 return fromIndex; 1881 } 1882 1883 int strLastIndex = targetOffset + targetCount - 1; 1884 char strLastChar = target[strLastIndex]; 1885 int min = sourceOffset + targetCount - 1; 1886 int i = min + fromIndex; 1887 1888 startSearchForLastChar: 1889 while (true) { 1890 while (i >= min && source[i] != strLastChar) { 1891 i--; 1892 } 1893 if (i < min) { 1894 return -1; 1895 } 1896 int j = i - 1; 1897 int start = j - (targetCount - 1); 1898 int k = strLastIndex - 1; 1899 1900 while (j > start) { 1901 if (source[j--] != target[k--]) { 1902 i--; 1903 continue startSearchForLastChar; 1904 } 1905 } 1906 return start - sourceOffset + 1; 1907 } 1908 } 1909 1910 /** 1911 * Returns a new string that is a substring of this string. The 1912 * substring begins with the character at the specified index and 1913 * extends to the end of this string. <p> 1914 * Examples: 1915 * <blockquote><pre> 1916 * "unhappy".substring(2) returns "happy" 1917 * "Harbison".substring(3) returns "bison" 1918 * "emptiness".substring(9) returns "" (an empty string) 1919 * </pre></blockquote> 1920 * 1921 * @param beginIndex the beginning index, inclusive. 1922 * @return the specified substring. 1923 * @exception IndexOutOfBoundsException if 1924 * {@code beginIndex} is negative or larger than the 1925 * length of this {@code String} object. 1926 */ 1927 public String substring(int beginIndex) { 1928 return substring(beginIndex, count); 1929 } 1930 1931 /** 1932 * Returns a new string that is a substring of this string. The 1933 * substring begins at the specified {@code beginIndex} and 1934 * extends to the character at index {@code endIndex - 1}. 1935 * Thus the length of the substring is {@code endIndex-beginIndex}. 1936 * <p> 1937 * Examples: 1938 * <blockquote><pre> 1939 * "hamburger".substring(4, 8) returns "urge" 1940 * "smiles".substring(1, 5) returns "mile" 1941 * </pre></blockquote> 1942 * 1943 * @param beginIndex the beginning index, inclusive. 1944 * @param endIndex the ending index, exclusive. 1945 * @return the specified substring. 1946 * @exception IndexOutOfBoundsException if the 1947 * {@code beginIndex} is negative, or 1948 * {@code endIndex} is larger than the length of 1949 * this {@code String} object, or 1950 * {@code beginIndex} is larger than 1951 * {@code endIndex}. 1952 */ 1953 public String substring(int beginIndex, int endIndex) { 1954 if (beginIndex < 0) { 1955 throw new StringIndexOutOfBoundsException(beginIndex); 1956 } 1957 if (endIndex > count) { 1958 throw new StringIndexOutOfBoundsException(endIndex); 1959 } 1960 if (beginIndex > endIndex) { 1961 throw new StringIndexOutOfBoundsException(endIndex - beginIndex); 1962 } 1963 return ((beginIndex == 0) && (endIndex == count)) ? this : 1964 new String(offset + beginIndex, endIndex - beginIndex, value); 1965 } 1966 1967 /** 1968 * Returns a new character sequence that is a subsequence of this sequence. 1969 * 1970 * <p> An invocation of this method of the form 1971 * 1972 * <blockquote><pre> 1973 * str.subSequence(begin, end)</pre></blockquote> 1974 * 1975 * behaves in exactly the same way as the invocation 1976 * 1977 * <blockquote><pre> 1978 * str.substring(begin, end)</pre></blockquote> 1979 * 1980 * This method is defined so that the <tt>String</tt> class can implement 1981 * the {@link CharSequence} interface. </p> 1982 * 1983 * @param beginIndex the begin index, inclusive. 1984 * @param endIndex the end index, exclusive. 1985 * @return the specified subsequence. 1986 * 1987 * @throws IndexOutOfBoundsException 1988 * if <tt>beginIndex</tt> or <tt>endIndex</tt> are negative, 1989 * if <tt>endIndex</tt> is greater than <tt>length()</tt>, 1990 * or if <tt>beginIndex</tt> is greater than <tt>startIndex</tt> 1991 * 1992 * @since 1.4 1993 * @spec JSR-51 1994 */ 1995 public CharSequence subSequence(int beginIndex, int endIndex) { 1996 return this.substring(beginIndex, endIndex); 1997 } 1998 1999 /** 2000 * Concatenates the specified string to the end of this string. 2001 * <p> 2002 * If the length of the argument string is {@code 0}, then this 2003 * {@code String} object is returned. Otherwise, a new 2004 * {@code String} object is created, representing a character 2005 * sequence that is the concatenation of the character sequence 2006 * represented by this {@code String} object and the character 2007 * sequence represented by the argument string.<p> 2008 * Examples: 2009 * <blockquote><pre> 2010 * "cares".concat("s") returns "caress" 2011 * "to".concat("get").concat("her") returns "together" 2012 * </pre></blockquote> 2013 * 2014 * @param str the {@code String} that is concatenated to the end 2015 * of this {@code String}. 2016 * @return a string that represents the concatenation of this object's 2017 * characters followed by the string argument's characters. 2018 */ 2019 public String concat(String str) { 2020 int otherLen = str.length(); 2021 if (otherLen == 0) { 2022 return this; 2023 } 2024 char buf[] = new char[count + otherLen]; 2025 getChars(0, count, buf, 0); 2026 str.getChars(0, otherLen, buf, count); 2027 return new String(0, count + otherLen, buf); 2028 } 2029 2030 /** 2031 * Returns a new string resulting from replacing all occurrences of 2032 * {@code oldChar} in this string with {@code newChar}. 2033 * <p> 2034 * If the character {@code oldChar} does not occur in the 2035 * character sequence represented by this {@code String} object, 2036 * then a reference to this {@code String} object is returned. 2037 * Otherwise, a new {@code String} object is created that 2038 * represents a character sequence identical to the character sequence 2039 * represented by this {@code String} object, except that every 2040 * occurrence of {@code oldChar} is replaced by an occurrence 2041 * of {@code newChar}. 2042 * <p> 2043 * Examples: 2044 * <blockquote><pre> 2045 * "mesquite in your cellar".replace('e', 'o') 2046 * returns "mosquito in your collar" 2047 * "the war of baronets".replace('r', 'y') 2048 * returns "the way of bayonets" 2049 * "sparring with a purple porpoise".replace('p', 't') 2050 * returns "starring with a turtle tortoise" 2051 * "JonL".replace('q', 'x') returns "JonL" (no change) 2052 * </pre></blockquote> 2053 * 2054 * @param oldChar the old character. 2055 * @param newChar the new character. 2056 * @return a string derived from this string by replacing every 2057 * occurrence of {@code oldChar} with {@code newChar}. 2058 */ 2059 public String replace(char oldChar, char newChar) { 2060 if (oldChar != newChar) { 2061 int len = count; 2062 int i = -1; 2063 char[] val = value; /* avoid getfield opcode */ 2064 int off = offset; /* avoid getfield opcode */ 2065 2066 while (++i < len) { 2067 if (val[off + i] == oldChar) { 2068 break; 2069 } 2070 } 2071 if (i < len) { 2072 char buf[] = new char[len]; 2073 for (int j = 0 ; j < i ; j++) { 2074 buf[j] = val[off+j]; 2075 } 2076 while (i < len) { 2077 char c = val[off + i]; 2078 buf[i] = (c == oldChar) ? newChar : c; 2079 i++; 2080 } 2081 return new String(0, len, buf); 2082 } 2083 } 2084 return this; 2085 } 2086 2087 /** 2088 * Tells whether or not this string matches the given <a 2089 * href="../util/regex/Pattern.html#sum">regular expression</a>. 2090 * 2091 * <p> An invocation of this method of the form 2092 * <i>str</i><tt>.matches(</tt><i>regex</i><tt>)</tt> yields exactly the 2093 * same result as the expression 2094 * 2095 * <blockquote><tt> {@link java.util.regex.Pattern}.{@link 2096 * java.util.regex.Pattern#matches(String,CharSequence) 2097 * matches}(</tt><i>regex</i><tt>,</tt> <i>str</i><tt>)</tt></blockquote> 2098 * 2099 * @param regex 2100 * the regular expression to which this string is to be matched 2101 * 2102 * @return <tt>true</tt> if, and only if, this string matches the 2103 * given regular expression 2104 * 2105 * @throws PatternSyntaxException 2106 * if the regular expression's syntax is invalid 2107 * 2108 * @see java.util.regex.Pattern 2109 * 2110 * @since 1.4 2111 * @spec JSR-51 2112 */ 2113 public boolean matches(String regex) { 2114 return Pattern.matches(regex, this); 2115 } 2116 2117 /** 2118 * Returns true if and only if this string contains the specified 2119 * sequence of char values. 2120 * 2121 * @param s the sequence to search for 2122 * @return true if this string contains {@code s}, false otherwise 2123 * @throws NullPointerException if {@code s} is {@code null} 2124 * @since 1.5 2125 */ 2126 public boolean contains(CharSequence s) { 2127 return indexOf(s.toString()) > -1; 2128 } 2129 2130 /** 2131 * Replaces the first substring of this string that matches the given <a 2132 * href="../util/regex/Pattern.html#sum">regular expression</a> with the 2133 * given replacement. 2134 * 2135 * <p> An invocation of this method of the form 2136 * <i>str</i><tt>.replaceFirst(</tt><i>regex</i><tt>,</tt> <i>repl</i><tt>)</tt> 2137 * yields exactly the same result as the expression 2138 * 2139 * <blockquote><tt> 2140 * {@link java.util.regex.Pattern}.{@link java.util.regex.Pattern#compile 2141 * compile}(</tt><i>regex</i><tt>).{@link 2142 * java.util.regex.Pattern#matcher(java.lang.CharSequence) 2143 * matcher}(</tt><i>str</i><tt>).{@link java.util.regex.Matcher#replaceFirst 2144 * replaceFirst}(</tt><i>repl</i><tt>)</tt></blockquote> 2145 * 2146 *<p> 2147 * Note that backslashes (<tt>\</tt>) and dollar signs (<tt>$</tt>) in the 2148 * replacement string may cause the results to be different than if it were 2149 * being treated as a literal replacement string; see 2150 * {@link java.util.regex.Matcher#replaceFirst}. 2151 * Use {@link java.util.regex.Matcher#quoteReplacement} to suppress the special 2152 * meaning of these characters, if desired. 2153 * 2154 * @param regex 2155 * the regular expression to which this string is to be matched 2156 * @param replacement 2157 * the string to be substituted for the first match 2158 * 2159 * @return The resulting <tt>String</tt> 2160 * 2161 * @throws PatternSyntaxException 2162 * if the regular expression's syntax is invalid 2163 * 2164 * @see java.util.regex.Pattern 2165 * 2166 * @since 1.4 2167 * @spec JSR-51 2168 */ 2169 public String replaceFirst(String regex, String replacement) { 2170 return Pattern.compile(regex).matcher(this).replaceFirst(replacement); 2171 } 2172 2173 /** 2174 * Replaces each substring of this string that matches the given <a 2175 * href="../util/regex/Pattern.html#sum">regular expression</a> with the 2176 * given replacement. 2177 * 2178 * <p> An invocation of this method of the form 2179 * <i>str</i><tt>.replaceAll(</tt><i>regex</i><tt>,</tt> <i>repl</i><tt>)</tt> 2180 * yields exactly the same result as the expression 2181 * 2182 * <blockquote><tt> 2183 * {@link java.util.regex.Pattern}.{@link java.util.regex.Pattern#compile 2184 * compile}(</tt><i>regex</i><tt>).{@link 2185 * java.util.regex.Pattern#matcher(java.lang.CharSequence) 2186 * matcher}(</tt><i>str</i><tt>).{@link java.util.regex.Matcher#replaceAll 2187 * replaceAll}(</tt><i>repl</i><tt>)</tt></blockquote> 2188 * 2189 *<p> 2190 * Note that backslashes (<tt>\</tt>) and dollar signs (<tt>$</tt>) in the 2191 * replacement string may cause the results to be different than if it were 2192 * being treated as a literal replacement string; see 2193 * {@link java.util.regex.Matcher#replaceAll Matcher.replaceAll}. 2194 * Use {@link java.util.regex.Matcher#quoteReplacement} to suppress the special 2195 * meaning of these characters, if desired. 2196 * 2197 * @param regex 2198 * the regular expression to which this string is to be matched 2199 * @param replacement 2200 * the string to be substituted for each match 2201 * 2202 * @return The resulting <tt>String</tt> 2203 * 2204 * @throws PatternSyntaxException 2205 * if the regular expression's syntax is invalid 2206 * 2207 * @see java.util.regex.Pattern 2208 * 2209 * @since 1.4 2210 * @spec JSR-51 2211 */ 2212 public String replaceAll(String regex, String replacement) { 2213 return Pattern.compile(regex).matcher(this).replaceAll(replacement); 2214 } 2215 2216 /** 2217 * Replaces each substring of this string that matches the literal target 2218 * sequence with the specified literal replacement sequence. The 2219 * replacement proceeds from the beginning of the string to the end, for 2220 * example, replacing "aa" with "b" in the string "aaa" will result in 2221 * "ba" rather than "ab". 2222 * 2223 * @param target The sequence of char values to be replaced 2224 * @param replacement The replacement sequence of char values 2225 * @return The resulting string 2226 * @throws NullPointerException if {@code target} or 2227 * {@code replacement} is {@code null}. 2228 * @since 1.5 2229 */ 2230 public String replace(CharSequence target, CharSequence replacement) { 2231 return Pattern.compile(target.toString(), Pattern.LITERAL).matcher( 2232 this).replaceAll(Matcher.quoteReplacement(replacement.toString())); 2233 } 2234 2235 /** 2236 * Splits this string around matches of the given 2237 * <a href="../util/regex/Pattern.html#sum">regular expression</a>. 2238 * 2239 * <p> The array returned by this method contains each substring of this 2240 * string that is terminated by another substring that matches the given 2241 * expression or is terminated by the end of the string. The substrings in 2242 * the array are in the order in which they occur in this string. If the 2243 * expression does not match any part of the input then the resulting array 2244 * has just one element, namely this string. 2245 * 2246 * <p> The <tt>limit</tt> parameter controls the number of times the 2247 * pattern is applied and therefore affects the length of the resulting 2248 * array. If the limit <i>n</i> is greater than zero then the pattern 2249 * will be applied at most <i>n</i> - 1 times, the array's 2250 * length will be no greater than <i>n</i>, and the array's last entry 2251 * will contain all input beyond the last matched delimiter. If <i>n</i> 2252 * is non-positive then the pattern will be applied as many times as 2253 * possible and the array can have any length. If <i>n</i> is zero then 2254 * the pattern will be applied as many times as possible, the array can 2255 * have any length, and trailing empty strings will be discarded. 2256 * 2257 * <p> The string <tt>"boo:and:foo"</tt>, for example, yields the 2258 * following results with these parameters: 2259 * 2260 * <blockquote><table cellpadding=1 cellspacing=0 summary="Split example showing regex, limit, and result"> 2261 * <tr> 2262 * <th>Regex</th> 2263 * <th>Limit</th> 2264 * <th>Result</th> 2265 * </tr> 2266 * <tr><td align=center>:</td> 2267 * <td align=center>2</td> 2268 * <td><tt>{ "boo", "and:foo" }</tt></td></tr> 2269 * <tr><td align=center>:</td> 2270 * <td align=center>5</td> 2271 * <td><tt>{ "boo", "and", "foo" }</tt></td></tr> 2272 * <tr><td align=center>:</td> 2273 * <td align=center>-2</td> 2274 * <td><tt>{ "boo", "and", "foo" }</tt></td></tr> 2275 * <tr><td align=center>o</td> 2276 * <td align=center>5</td> 2277 * <td><tt>{ "b", "", ":and:f", "", "" }</tt></td></tr> 2278 * <tr><td align=center>o</td> 2279 * <td align=center>-2</td> 2280 * <td><tt>{ "b", "", ":and:f", "", "" }</tt></td></tr> 2281 * <tr><td align=center>o</td> 2282 * <td align=center>0</td> 2283 * <td><tt>{ "b", "", ":and:f" }</tt></td></tr> 2284 * </table></blockquote> 2285 * 2286 * <p> An invocation of this method of the form 2287 * <i>str.</i><tt>split(</tt><i>regex</i><tt>,</tt> <i>n</i><tt>)</tt> 2288 * yields the same result as the expression 2289 * 2290 * <blockquote> 2291 * {@link java.util.regex.Pattern}.{@link java.util.regex.Pattern#compile 2292 * compile}<tt>(</tt><i>regex</i><tt>)</tt>.{@link 2293 * java.util.regex.Pattern#split(java.lang.CharSequence,int) 2294 * split}<tt>(</tt><i>str</i><tt>,</tt> <i>n</i><tt>)</tt> 2295 * </blockquote> 2296 * 2297 * 2298 * @param regex 2299 * the delimiting regular expression 2300 * 2301 * @param limit 2302 * the result threshold, as described above 2303 * 2304 * @return the array of strings computed by splitting this string 2305 * around matches of the given regular expression 2306 * 2307 * @throws PatternSyntaxException 2308 * if the regular expression's syntax is invalid 2309 * 2310 * @see java.util.regex.Pattern 2311 * 2312 * @since 1.4 2313 * @spec JSR-51 2314 */ 2315 public String[] split(String regex, int limit) { 2316 /* fastpath if the regex is a 2317 (1)one-char String and this character is not one of the 2318 RegEx's meta characters ".$|()[{^?*+\\", or 2319 (2)two-char String and the first char is the backslash and 2320 the second is not the ascii digit or ascii letter. 2321 */ 2322 char ch = 0; 2323 if (((regex.count == 1 && 2324 ".$|()[{^?*+\\".indexOf(ch = regex.charAt(0)) == -1) || 2325 (regex.length() == 2 && 2326 regex.charAt(0) == '\\' && 2327 (((ch = regex.charAt(1))-'0')|('9'-ch)) < 0 && 2328 ((ch-'a')|('z'-ch)) < 0 && 2329 ((ch-'A')|('Z'-ch)) < 0)) && 2330 (ch < Character.MIN_HIGH_SURROGATE || 2331 ch > Character.MAX_LOW_SURROGATE)) 2332 { 2333 int off = 0; 2334 int next = 0; 2335 boolean limited = limit > 0; 2336 ArrayList<String> list = new ArrayList<>(); 2337 while ((next = indexOf(ch, off)) != -1) { 2338 if (!limited || list.size() < limit - 1) { 2339 list.add(substring(off, next)); 2340 off = next + 1; 2341 } else { // last one 2342 //assert (list.size() == limit - 1); 2343 list.add(substring(off, count)); 2344 off = count; 2345 break; 2346 } 2347 } 2348 // If no match was found, return this 2349 if (off == 0) 2350 return new String[] { this }; 2351 2352 // Add remaining segment 2353 if (!limited || list.size() < limit) 2354 list.add(substring(off, count)); 2355 2356 // Construct result 2357 int resultSize = list.size(); 2358 if (limit == 0) 2359 while (resultSize > 0 && list.get(resultSize-1).length() == 0) 2360 resultSize--; 2361 String[] result = new String[resultSize]; 2362 return list.subList(0, resultSize).toArray(result); 2363 } 2364 return Pattern.compile(regex).split(this, limit); 2365 } 2366 2367 /** 2368 * Splits this string around matches of the given <a 2369 * href="../util/regex/Pattern.html#sum">regular expression</a>. 2370 * 2371 * <p> This method works as if by invoking the two-argument {@link 2372 * #split(String, int) split} method with the given expression and a limit 2373 * argument of zero. Trailing empty strings are therefore not included in 2374 * the resulting array. 2375 * 2376 * <p> The string <tt>"boo:and:foo"</tt>, for example, yields the following 2377 * results with these expressions: 2378 * 2379 * <blockquote><table cellpadding=1 cellspacing=0 summary="Split examples showing regex and result"> 2380 * <tr> 2381 * <th>Regex</th> 2382 * <th>Result</th> 2383 * </tr> 2384 * <tr><td align=center>:</td> 2385 * <td><tt>{ "boo", "and", "foo" }</tt></td></tr> 2386 * <tr><td align=center>o</td> 2387 * <td><tt>{ "b", "", ":and:f" }</tt></td></tr> 2388 * </table></blockquote> 2389 * 2390 * 2391 * @param regex 2392 * the delimiting regular expression 2393 * 2394 * @return the array of strings computed by splitting this string 2395 * around matches of the given regular expression 2396 * 2397 * @throws PatternSyntaxException 2398 * if the regular expression's syntax is invalid 2399 * 2400 * @see java.util.regex.Pattern 2401 * 2402 * @since 1.4 2403 * @spec JSR-51 2404 */ 2405 public String[] split(String regex) { 2406 return split(regex, 0); 2407 } 2408 2409 /** 2410 * Converts all of the characters in this {@code String} to lower 2411 * case using the rules of the given {@code Locale}. Case mapping is based 2412 * on the Unicode Standard version specified by the {@link java.lang.Character Character} 2413 * class. Since case mappings are not always 1:1 char mappings, the resulting 2414 * {@code String} may be a different length than the original {@code String}. 2415 * <p> 2416 * Examples of lowercase mappings are in the following table: 2417 * <table border="1" summary="Lowercase mapping examples showing language code of locale, upper case, lower case, and description"> 2418 * <tr> 2419 * <th>Language Code of Locale</th> 2420 * <th>Upper Case</th> 2421 * <th>Lower Case</th> 2422 * <th>Description</th> 2423 * </tr> 2424 * <tr> 2425 * <td>tr (Turkish)</td> 2426 * <td>\u0130</td> 2427 * <td>\u0069</td> 2428 * <td>capital letter I with dot above -> small letter i</td> 2429 * </tr> 2430 * <tr> 2431 * <td>tr (Turkish)</td> 2432 * <td>\u0049</td> 2433 * <td>\u0131</td> 2434 * <td>capital letter I -> small letter dotless i </td> 2435 * </tr> 2436 * <tr> 2437 * <td>(all)</td> 2438 * <td>French Fries</td> 2439 * <td>french fries</td> 2440 * <td>lowercased all chars in String</td> 2441 * </tr> 2442 * <tr> 2443 * <td>(all)</td> 2444 * <td><img src="doc-files/capiota.gif" alt="capiota"><img src="doc-files/capchi.gif" alt="capchi"> 2445 * <img src="doc-files/captheta.gif" alt="captheta"><img src="doc-files/capupsil.gif" alt="capupsil"> 2446 * <img src="doc-files/capsigma.gif" alt="capsigma"></td> 2447 * <td><img src="doc-files/iota.gif" alt="iota"><img src="doc-files/chi.gif" alt="chi"> 2448 * <img src="doc-files/theta.gif" alt="theta"><img src="doc-files/upsilon.gif" alt="upsilon"> 2449 * <img src="doc-files/sigma1.gif" alt="sigma"></td> 2450 * <td>lowercased all chars in String</td> 2451 * </tr> 2452 * </table> 2453 * 2454 * @param locale use the case transformation rules for this locale 2455 * @return the {@code String}, converted to lowercase. 2456 * @see java.lang.String#toLowerCase() 2457 * @see java.lang.String#toUpperCase() 2458 * @see java.lang.String#toUpperCase(Locale) 2459 * @since 1.1 2460 */ 2461 public String toLowerCase(Locale locale) { 2462 if (locale == null) { 2463 throw new NullPointerException(); 2464 } 2465 2466 int firstUpper; 2467 2468 /* Now check if there are any characters that need to be changed. */ 2469 scan: { 2470 for (firstUpper = 0 ; firstUpper < count; ) { 2471 char c = value[offset+firstUpper]; 2472 if ((c >= Character.MIN_HIGH_SURROGATE) && 2473 (c <= Character.MAX_HIGH_SURROGATE)) { 2474 int supplChar = codePointAt(firstUpper); 2475 if (supplChar != Character.toLowerCase(supplChar)) { 2476 break scan; 2477 } 2478 firstUpper += Character.charCount(supplChar); 2479 } else { 2480 if (c != Character.toLowerCase(c)) { 2481 break scan; 2482 } 2483 firstUpper++; 2484 } 2485 } 2486 return this; 2487 } 2488 2489 char[] result = new char[count]; 2490 int resultOffset = 0; /* result may grow, so i+resultOffset 2491 * is the write location in result */ 2492 2493 /* Just copy the first few lowerCase characters. */ 2494 System.arraycopy(value, offset, result, 0, firstUpper); 2495 2496 String lang = locale.getLanguage(); 2497 boolean localeDependent = 2498 (lang == "tr" || lang == "az" || lang == "lt"); 2499 char[] lowerCharArray; 2500 int lowerChar; 2501 int srcChar; 2502 int srcCount; 2503 for (int i = firstUpper; i < count; i += srcCount) { 2504 srcChar = (int)value[offset+i]; 2505 if ((char)srcChar >= Character.MIN_HIGH_SURROGATE && 2506 (char)srcChar <= Character.MAX_HIGH_SURROGATE) { 2507 srcChar = codePointAt(i); 2508 srcCount = Character.charCount(srcChar); 2509 } else { 2510 srcCount = 1; 2511 } 2512 if (localeDependent || srcChar == '\u03A3') { // GREEK CAPITAL LETTER SIGMA 2513 lowerChar = ConditionalSpecialCasing.toLowerCaseEx(this, i, locale); 2514 } else if (srcChar == '\u0130') { // LATIN CAPITAL LETTER I DOT 2515 lowerChar = Character.ERROR; 2516 } else { 2517 lowerChar = Character.toLowerCase(srcChar); 2518 } 2519 if ((lowerChar == Character.ERROR) || 2520 (lowerChar >= Character.MIN_SUPPLEMENTARY_CODE_POINT)) { 2521 if (lowerChar == Character.ERROR) { 2522 if (!localeDependent && srcChar == '\u0130') { 2523 lowerCharArray = 2524 ConditionalSpecialCasing.toLowerCaseCharArray(this, i, Locale.ENGLISH); 2525 } else { 2526 lowerCharArray = 2527 ConditionalSpecialCasing.toLowerCaseCharArray(this, i, locale); 2528 } 2529 } else if (srcCount == 2) { 2530 resultOffset += Character.toChars(lowerChar, result, i + resultOffset) - srcCount; 2531 continue; 2532 } else { 2533 lowerCharArray = Character.toChars(lowerChar); 2534 } 2535 2536 /* Grow result if needed */ 2537 int mapLen = lowerCharArray.length; 2538 if (mapLen > srcCount) { 2539 char[] result2 = new char[result.length + mapLen - srcCount]; 2540 System.arraycopy(result, 0, result2, 0, 2541 i + resultOffset); 2542 result = result2; 2543 } 2544 for (int x=0; x<mapLen; ++x) { 2545 result[i+resultOffset+x] = lowerCharArray[x]; 2546 } 2547 resultOffset += (mapLen - srcCount); 2548 } else { 2549 result[i+resultOffset] = (char)lowerChar; 2550 } 2551 } 2552 return new String(0, count+resultOffset, result); 2553 } 2554 2555 /** 2556 * Converts all of the characters in this {@code String} to lower 2557 * case using the rules of the default locale. This is equivalent to calling 2558 * {@code toLowerCase(Locale.getDefault())}. 2559 * <p> 2560 * <b>Note:</b> This method is locale sensitive, and may produce unexpected 2561 * results if used for strings that are intended to be interpreted locale 2562 * independently. 2563 * Examples are programming language identifiers, protocol keys, and HTML 2564 * tags. 2565 * For instance, {@code "TITLE".toLowerCase()} in a Turkish locale 2566 * returns {@code "t\u005Cu0131tle"}, where '\u005Cu0131' is the 2567 * LATIN SMALL LETTER DOTLESS I character. 2568 * To obtain correct results for locale insensitive strings, use 2569 * {@code toLowerCase(Locale.ENGLISH)}. 2570 * <p> 2571 * @return the {@code String}, converted to lowercase. 2572 * @see java.lang.String#toLowerCase(Locale) 2573 */ 2574 public String toLowerCase() { 2575 return toLowerCase(Locale.getDefault()); 2576 } 2577 2578 /** 2579 * Converts all of the characters in this {@code String} to upper 2580 * case using the rules of the given {@code Locale}. Case mapping is based 2581 * on the Unicode Standard version specified by the {@link java.lang.Character Character} 2582 * class. Since case mappings are not always 1:1 char mappings, the resulting 2583 * {@code String} may be a different length than the original {@code String}. 2584 * <p> 2585 * Examples of locale-sensitive and 1:M case mappings are in the following table. 2586 * <p> 2587 * <table border="1" summary="Examples of locale-sensitive and 1:M case mappings. Shows Language code of locale, lower case, upper case, and description."> 2588 * <tr> 2589 * <th>Language Code of Locale</th> 2590 * <th>Lower Case</th> 2591 * <th>Upper Case</th> 2592 * <th>Description</th> 2593 * </tr> 2594 * <tr> 2595 * <td>tr (Turkish)</td> 2596 * <td>\u0069</td> 2597 * <td>\u0130</td> 2598 * <td>small letter i -> capital letter I with dot above</td> 2599 * </tr> 2600 * <tr> 2601 * <td>tr (Turkish)</td> 2602 * <td>\u0131</td> 2603 * <td>\u0049</td> 2604 * <td>small letter dotless i -> capital letter I</td> 2605 * </tr> 2606 * <tr> 2607 * <td>(all)</td> 2608 * <td>\u00df</td> 2609 * <td>\u0053 \u0053</td> 2610 * <td>small letter sharp s -> two letters: SS</td> 2611 * </tr> 2612 * <tr> 2613 * <td>(all)</td> 2614 * <td>Fahrvergnügen</td> 2615 * <td>FAHRVERGNÜGEN</td> 2616 * <td></td> 2617 * </tr> 2618 * </table> 2619 * @param locale use the case transformation rules for this locale 2620 * @return the {@code String}, converted to uppercase. 2621 * @see java.lang.String#toUpperCase() 2622 * @see java.lang.String#toLowerCase() 2623 * @see java.lang.String#toLowerCase(Locale) 2624 * @since 1.1 2625 */ 2626 public String toUpperCase(Locale locale) { 2627 if (locale == null) { 2628 throw new NullPointerException(); 2629 } 2630 2631 int firstLower; 2632 2633 /* Now check if there are any characters that need to be changed. */ 2634 scan: { 2635 for (firstLower = 0 ; firstLower < count; ) { 2636 int c = (int)value[offset+firstLower]; 2637 int srcCount; 2638 if ((c >= Character.MIN_HIGH_SURROGATE) && 2639 (c <= Character.MAX_HIGH_SURROGATE)) { 2640 c = codePointAt(firstLower); 2641 srcCount = Character.charCount(c); 2642 } else { 2643 srcCount = 1; 2644 } 2645 int upperCaseChar = Character.toUpperCaseEx(c); 2646 if ((upperCaseChar == Character.ERROR) || 2647 (c != upperCaseChar)) { 2648 break scan; 2649 } 2650 firstLower += srcCount; 2651 } 2652 return this; 2653 } 2654 2655 char[] result = new char[count]; /* may grow */ 2656 int resultOffset = 0; /* result may grow, so i+resultOffset 2657 * is the write location in result */ 2658 2659 /* Just copy the first few upperCase characters. */ 2660 System.arraycopy(value, offset, result, 0, firstLower); 2661 2662 String lang = locale.getLanguage(); 2663 boolean localeDependent = 2664 (lang == "tr" || lang == "az" || lang == "lt"); 2665 char[] upperCharArray; 2666 int upperChar; 2667 int srcChar; 2668 int srcCount; 2669 for (int i = firstLower; i < count; i += srcCount) { 2670 srcChar = (int)value[offset+i]; 2671 if ((char)srcChar >= Character.MIN_HIGH_SURROGATE && 2672 (char)srcChar <= Character.MAX_HIGH_SURROGATE) { 2673 srcChar = codePointAt(i); 2674 srcCount = Character.charCount(srcChar); 2675 } else { 2676 srcCount = 1; 2677 } 2678 if (localeDependent) { 2679 upperChar = ConditionalSpecialCasing.toUpperCaseEx(this, i, locale); 2680 } else { 2681 upperChar = Character.toUpperCaseEx(srcChar); 2682 } 2683 if ((upperChar == Character.ERROR) || 2684 (upperChar >= Character.MIN_SUPPLEMENTARY_CODE_POINT)) { 2685 if (upperChar == Character.ERROR) { 2686 if (localeDependent) { 2687 upperCharArray = 2688 ConditionalSpecialCasing.toUpperCaseCharArray(this, i, locale); 2689 } else { 2690 upperCharArray = Character.toUpperCaseCharArray(srcChar); 2691 } 2692 } else if (srcCount == 2) { 2693 resultOffset += Character.toChars(upperChar, result, i + resultOffset) - srcCount; 2694 continue; 2695 } else { 2696 upperCharArray = Character.toChars(upperChar); 2697 } 2698 2699 /* Grow result if needed */ 2700 int mapLen = upperCharArray.length; 2701 if (mapLen > srcCount) { 2702 char[] result2 = new char[result.length + mapLen - srcCount]; 2703 System.arraycopy(result, 0, result2, 0, 2704 i + resultOffset); 2705 result = result2; 2706 } 2707 for (int x=0; x<mapLen; ++x) { 2708 result[i+resultOffset+x] = upperCharArray[x]; 2709 } 2710 resultOffset += (mapLen - srcCount); 2711 } else { 2712 result[i+resultOffset] = (char)upperChar; 2713 } 2714 } 2715 return new String(0, count+resultOffset, result); 2716 } 2717 2718 /** 2719 * Converts all of the characters in this {@code String} to upper 2720 * case using the rules of the default locale. This method is equivalent to 2721 * {@code toUpperCase(Locale.getDefault())}. 2722 * <p> 2723 * <b>Note:</b> This method is locale sensitive, and may produce unexpected 2724 * results if used for strings that are intended to be interpreted locale 2725 * independently. 2726 * Examples are programming language identifiers, protocol keys, and HTML 2727 * tags. 2728 * For instance, {@code "title".toUpperCase()} in a Turkish locale 2729 * returns {@code "T\u005Cu0130TLE"}, where '\u005Cu0130' is the 2730 * LATIN CAPITAL LETTER I WITH DOT ABOVE character. 2731 * To obtain correct results for locale insensitive strings, use 2732 * {@code toUpperCase(Locale.ENGLISH)}. 2733 * <p> 2734 * @return the {@code String}, converted to uppercase. 2735 * @see java.lang.String#toUpperCase(Locale) 2736 */ 2737 public String toUpperCase() { 2738 return toUpperCase(Locale.getDefault()); 2739 } 2740 2741 /** 2742 * Returns a copy of the string, with leading and trailing whitespace 2743 * omitted. 2744 * <p> 2745 * If this {@code String} object represents an empty character 2746 * sequence, or the first and last characters of character sequence 2747 * represented by this {@code String} object both have codes 2748 * greater than {@code '\u005Cu0020'} (the space character), then a 2749 * reference to this {@code String} object is returned. 2750 * <p> 2751 * Otherwise, if there is no character with a code greater than 2752 * {@code '\u005Cu0020'} in the string, then a new 2753 * {@code String} object representing an empty string is created 2754 * and returned. 2755 * <p> 2756 * Otherwise, let <i>k</i> be the index of the first character in the 2757 * string whose code is greater than {@code '\u005Cu0020'}, and let 2758 * <i>m</i> be the index of the last character in the string whose code 2759 * is greater than {@code '\u005Cu0020'}. A new {@code String} 2760 * object is created, representing the substring of this string that 2761 * begins with the character at index <i>k</i> and ends with the 2762 * character at index <i>m</i>-that is, the result of 2763 * <code>this.substring(<i>k</i>, <i>m</i>+1)</code>. 2764 * <p> 2765 * This method may be used to trim whitespace (as defined above) from 2766 * the beginning and end of a string. 2767 * 2768 * @return A copy of this string with leading and trailing white 2769 * space removed, or this string if it has no leading or 2770 * trailing white space. 2771 */ 2772 public String trim() { 2773 int len = count; 2774 int st = 0; 2775 int off = offset; /* avoid getfield opcode */ 2776 char[] val = value; /* avoid getfield opcode */ 2777 2778 while ((st < len) && (val[off + st] <= ' ')) { 2779 st++; 2780 } 2781 while ((st < len) && (val[off + len - 1] <= ' ')) { 2782 len--; 2783 } 2784 return ((st > 0) || (len < count)) ? substring(st, len) : this; 2785 } 2786 2787 /** 2788 * This object (which is already a string!) is itself returned. 2789 * 2790 * @return the string itself. 2791 */ 2792 public String toString() { 2793 return this; 2794 } 2795 2796 /** 2797 * Converts this string to a new character array. 2798 * 2799 * @return a newly allocated character array whose length is the length 2800 * of this string and whose contents are initialized to contain 2801 * the character sequence represented by this string. 2802 */ 2803 public char[] toCharArray() { 2804 char result[] = new char[count]; 2805 getChars(0, count, result, 0); 2806 return result; 2807 } 2808 2809 /** 2810 * Returns a formatted string using the specified format string and 2811 * arguments. 2812 * 2813 * <p> The locale always used is the one returned by {@link 2814 * java.util.Locale#getDefault() Locale.getDefault()}. 2815 * 2816 * @param format 2817 * A <a href="../util/Formatter.html#syntax">format string</a> 2818 * 2819 * @param args 2820 * Arguments referenced by the format specifiers in the format 2821 * string. If there are more arguments than format specifiers, the 2822 * extra arguments are ignored. The number of arguments is 2823 * variable and may be zero. The maximum number of arguments is 2824 * limited by the maximum dimension of a Java array as defined by 2825 * <cite>The Java™ Virtual Machine Specification</cite>. 2826 * The behaviour on a 2827 * <tt>null</tt> argument depends on the <a 2828 * href="../util/Formatter.html#syntax">conversion</a>. 2829 * 2830 * @throws IllegalFormatException 2831 * If a format string contains an illegal syntax, a format 2832 * specifier that is incompatible with the given arguments, 2833 * insufficient arguments given the format string, or other 2834 * illegal conditions. For specification of all possible 2835 * formatting errors, see the <a 2836 * href="../util/Formatter.html#detail">Details</a> section of the 2837 * formatter class specification. 2838 * 2839 * @throws NullPointerException 2840 * If the <tt>format</tt> is <tt>null</tt> 2841 * 2842 * @return A formatted string 2843 * 2844 * @see java.util.Formatter 2845 * @since 1.5 2846 */ 2847 public static String format(String format, Object ... args) { 2848 return new Formatter().format(format, args).toString(); 2849 } 2850 2851 /** 2852 * Returns a formatted string using the specified locale, format string, 2853 * and arguments. 2854 * 2855 * @param l 2856 * The {@linkplain java.util.Locale locale} to apply during 2857 * formatting. If <tt>l</tt> is <tt>null</tt> then no localization 2858 * is applied. 2859 * 2860 * @param format 2861 * A <a href="../util/Formatter.html#syntax">format string</a> 2862 * 2863 * @param args 2864 * Arguments referenced by the format specifiers in the format 2865 * string. If there are more arguments than format specifiers, the 2866 * extra arguments are ignored. The number of arguments is 2867 * variable and may be zero. The maximum number of arguments is 2868 * limited by the maximum dimension of a Java array as defined by 2869 * <cite>The Java™ Virtual Machine Specification</cite>. 2870 * The behaviour on a 2871 * <tt>null</tt> argument depends on the <a 2872 * href="../util/Formatter.html#syntax">conversion</a>. 2873 * 2874 * @throws IllegalFormatException 2875 * If a format string contains an illegal syntax, a format 2876 * specifier that is incompatible with the given arguments, 2877 * insufficient arguments given the format string, or other 2878 * illegal conditions. For specification of all possible 2879 * formatting errors, see the <a 2880 * href="../util/Formatter.html#detail">Details</a> section of the 2881 * formatter class specification 2882 * 2883 * @throws NullPointerException 2884 * If the <tt>format</tt> is <tt>null</tt> 2885 * 2886 * @return A formatted string 2887 * 2888 * @see java.util.Formatter 2889 * @since 1.5 2890 */ 2891 public static String format(Locale l, String format, Object ... args) { 2892 return new Formatter(l).format(format, args).toString(); 2893 } 2894 2895 /** 2896 * Returns the string representation of the {@code Object} argument. 2897 * 2898 * @param obj an {@code Object}. 2899 * @return if the argument is {@code null}, then a string equal to 2900 * {@code "null"}; otherwise, the value of 2901 * {@code obj.toString()} is returned. 2902 * @see java.lang.Object#toString() 2903 */ 2904 public static String valueOf(Object obj) { 2905 return (obj == null) ? "null" : obj.toString(); 2906 } 2907 2908 /** 2909 * Returns the string representation of the {@code char} array 2910 * argument. The contents of the character array are copied; subsequent 2911 * modification of the character array does not affect the newly 2912 * created string. 2913 * 2914 * @param data a {@code char} array. 2915 * @return a newly allocated string representing the same sequence of 2916 * characters contained in the character array argument. 2917 */ 2918 public static String valueOf(char data[]) { 2919 return new String(data); 2920 } 2921 2922 /** 2923 * Returns the string representation of a specific subarray of the 2924 * {@code char} array argument. 2925 * <p> 2926 * The {@code offset} argument is the index of the first 2927 * character of the subarray. The {@code count} argument 2928 * specifies the length of the subarray. The contents of the subarray 2929 * are copied; subsequent modification of the character array does not 2930 * affect the newly created string. 2931 * 2932 * @param data the character array. 2933 * @param offset the initial offset into the value of the 2934 * {@code String}. 2935 * @param count the length of the value of the {@code String}. 2936 * @return a string representing the sequence of characters contained 2937 * in the subarray of the character array argument. 2938 * @exception IndexOutOfBoundsException if {@code offset} is 2939 * negative, or {@code count} is negative, or 2940 * {@code offset+count} is larger than 2941 * {@code data.length}. 2942 */ 2943 public static String valueOf(char data[], int offset, int count) { 2944 return new String(data, offset, count); 2945 } 2946 2947 /** 2948 * Returns a String that represents the character sequence in the 2949 * array specified. 2950 * 2951 * @param data the character array. 2952 * @param offset initial offset of the subarray. 2953 * @param count length of the subarray. 2954 * @return a {@code String} that contains the characters of the 2955 * specified subarray of the character array. 2956 */ 2957 public static String copyValueOf(char data[], int offset, int count) { 2958 // All public String constructors now copy the data. 2959 return new String(data, offset, count); 2960 } 2961 2962 /** 2963 * Returns a String that represents the character sequence in the 2964 * array specified. 2965 * 2966 * @param data the character array. 2967 * @return a {@code String} that contains the characters of the 2968 * character array. 2969 */ 2970 public static String copyValueOf(char data[]) { 2971 return copyValueOf(data, 0, data.length); 2972 } 2973 2974 /** 2975 * Returns the string representation of the {@code boolean} argument. 2976 * 2977 * @param b a {@code boolean}. 2978 * @return if the argument is {@code true}, a string equal to 2979 * {@code "true"} is returned; otherwise, a string equal to 2980 * {@code "false"} is returned. 2981 */ 2982 public static String valueOf(boolean b) { 2983 return b ? "true" : "false"; 2984 } 2985 2986 /** 2987 * Returns the string representation of the {@code char} 2988 * argument. 2989 * 2990 * @param c a {@code char}. 2991 * @return a string of length {@code 1} containing 2992 * as its single character the argument {@code c}. 2993 */ 2994 public static String valueOf(char c) { 2995 char data[] = {c}; 2996 return new String(0, 1, data); 2997 } 2998 2999 /** 3000 * Returns the string representation of the {@code int} argument. 3001 * <p> 3002 * The representation is exactly the one returned by the 3003 * {@code Integer.toString} method of one argument. 3004 * 3005 * @param i an {@code int}. 3006 * @return a string representation of the {@code int} argument. 3007 * @see java.lang.Integer#toString(int, int) 3008 */ 3009 public static String valueOf(int i) { 3010 return Integer.toString(i); 3011 } 3012 3013 /** 3014 * Returns the string representation of the {@code long} argument. 3015 * <p> 3016 * The representation is exactly the one returned by the 3017 * {@code Long.toString} method of one argument. 3018 * 3019 * @param l a {@code long}. 3020 * @return a string representation of the {@code long} argument. 3021 * @see java.lang.Long#toString(long) 3022 */ 3023 public static String valueOf(long l) { 3024 return Long.toString(l); 3025 } 3026 3027 /** 3028 * Returns the string representation of the {@code float} argument. 3029 * <p> 3030 * The representation is exactly the one returned by the 3031 * {@code Float.toString} method of one argument. 3032 * 3033 * @param f a {@code float}. 3034 * @return a string representation of the {@code float} argument. 3035 * @see java.lang.Float#toString(float) 3036 */ 3037 public static String valueOf(float f) { 3038 return Float.toString(f); 3039 } 3040 3041 /** 3042 * Returns the string representation of the {@code double} argument. 3043 * <p> 3044 * The representation is exactly the one returned by the 3045 * {@code Double.toString} method of one argument. 3046 * 3047 * @param d a {@code double}. 3048 * @return a string representation of the {@code double} argument. 3049 * @see java.lang.Double#toString(double) 3050 */ 3051 public static String valueOf(double d) { 3052 return Double.toString(d); 3053 } 3054 3055 /** 3056 * Returns a canonical representation for the string object. 3057 * <p> 3058 * A pool of strings, initially empty, is maintained privately by the 3059 * class {@code String}. 3060 * <p> 3061 * When the intern method is invoked, if the pool already contains a 3062 * string equal to this {@code String} object as determined by 3063 * the {@link #equals(Object)} method, then the string from the pool is 3064 * returned. Otherwise, this {@code String} object is added to the 3065 * pool and a reference to this {@code String} object is returned. 3066 * <p> 3067 * It follows that for any two strings {@code s} and {@code t}, 3068 * {@code s.intern() == t.intern()} is {@code true} 3069 * if and only if {@code s.equals(t)} is {@code true}. 3070 * <p> 3071 * All literal strings and string-valued constant expressions are 3072 * interned. String literals are defined in section 3.10.5 of the 3073 * <cite>The Java™ Language Specification</cite>. 3074 * 3075 * @return a string that has the same contents as this string, but is 3076 * guaranteed to be from a pool of unique strings. 3077 */ 3078 public native String intern(); 3079 3080 /** 3081 * Seed value used for each alternative hash calculated. 3082 */ 3083 private static final int HASHING_SEED; 3084 3085 static { 3086 // ??? Stronger random source? (Random/SecureRandom is not available) 3087 HASHING_SEED = System.identityHashCode(String.class) 3088 ^ System.identityHashCode(System.class) 3089 ^ System.identityHashCode(Thread.currentThread()) 3090 ^ (int) (System.currentTimeMillis() >>> 2) // resolution is poor 3091 ^ (int) (System.nanoTime() >>> 5); // resolution is poor 3092 } 3093 3094 /** 3095 * Cached value of the hashing algorithm result 3096 */ 3097 private transient int hash32 = 0; 3098 3099 /** 3100 * {@inheritDoc} 3101 * 3102 * <p/> 3103 * The hash value will never be zero. 3104 */ 3105 public int hash32() { 3106 int h = hash32; 3107 if (0 == h) { 3108 // harmless data race on hash32 here. 3109 h = Hashing.murmur3_32(HASHING_SEED, value, offset, count); 3110 3111 // ensure result is not zero to avoid recalcing 3112 h = (0 != h) ? h : 1; 3113 3114 hash32 = h; 3115 } 3116 3117 return h; 3118 } 3119 }