1 /* 2 * Copyright (c) 1996, 2019, 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 /* 27 * (C) Copyright Taligent, Inc. 1996, 1997 - All Rights Reserved 28 * (C) Copyright IBM Corp. 1996 - 1998 - All Rights Reserved 29 * 30 * The original version of this source code and documentation is copyrighted 31 * and owned by Taligent, Inc., a wholly-owned subsidiary of IBM. These 32 * materials are provided under terms of a License Agreement between Taligent 33 * and Sun. This technology is protected by multiple US and International 34 * patents. This notice and attribution to Taligent may not be removed. 35 * Taligent is a registered trademark of Taligent, Inc. 36 * 37 */ 38 39 package java.text; 40 41 import java.io.InvalidObjectException; 42 import java.io.IOException; 43 import java.io.ObjectInputStream; 44 import java.util.Arrays; 45 46 /** 47 * A <code>ChoiceFormat</code> allows you to attach a format to a range of numbers. 48 * It is generally used in a <code>MessageFormat</code> for handling plurals. 49 * The choice is specified with an ascending list of doubles, where each item 50 * specifies a half-open interval up to the next item: 51 * <blockquote> 52 * <pre> 53 * X matches j if and only if limit[j] ≤ X < limit[j+1] 54 * </pre> 55 * </blockquote> 56 * If there is no match, then either the first or last index is used, depending 57 * on whether the number (X) is too low or too high. If the limit array is not 58 * in ascending order, the results of formatting will be incorrect. ChoiceFormat 59 * also accepts <code>\u221E</code> as equivalent to infinity(INF). 60 * 61 * <p> 62 * <strong>Note:</strong> 63 * <code>ChoiceFormat</code> differs from the other <code>Format</code> 64 * classes in that you create a <code>ChoiceFormat</code> object with a 65 * constructor (not with a <code>getInstance</code> style factory 66 * method). The factory methods aren't necessary because <code>ChoiceFormat</code> 67 * doesn't require any complex setup for a given locale. In fact, 68 * <code>ChoiceFormat</code> doesn't implement any locale specific behavior. 69 * 70 * <p> 71 * When creating a <code>ChoiceFormat</code>, you must specify an array of formats 72 * and an array of limits. The length of these arrays must be the same. 73 * For example, 74 * <ul> 75 * <li> 76 * <em>limits</em> = {1,2,3,4,5,6,7}<br> 77 * <em>formats</em> = {"Sun","Mon","Tue","Wed","Thur","Fri","Sat"} 78 * <li> 79 * <em>limits</em> = {0, 1, ChoiceFormat.nextDouble(1)}<br> 80 * <em>formats</em> = {"no files", "one file", "many files"}<br> 81 * (<code>nextDouble</code> can be used to get the next higher double, to 82 * make the half-open interval.) 83 * </ul> 84 * 85 * <p> 86 * Here is a simple example that shows formatting and parsing: 87 * <blockquote> 88 * <pre>{@code 89 * double[] limits = {1,2,3,4,5,6,7}; 90 * String[] dayOfWeekNames = {"Sun","Mon","Tue","Wed","Thur","Fri","Sat"}; 91 * ChoiceFormat form = new ChoiceFormat(limits, dayOfWeekNames); 92 * ParsePosition status = new ParsePosition(0); 93 * for (double i = 0.0; i <= 8.0; ++i) { 94 * status.setIndex(0); 95 * System.out.println(i + " -> " + form.format(i) + " -> " 96 * + form.parse(form.format(i),status)); 97 * } 98 * }</pre> 99 * </blockquote> 100 * Here is a more complex example, with a pattern format: 101 * <blockquote> 102 * <pre>{@code 103 * double[] filelimits = {0,1,2}; 104 * String[] filepart = {"are no files","is one file","are {2} files"}; 105 * ChoiceFormat fileform = new ChoiceFormat(filelimits, filepart); 106 * Format[] testFormats = {fileform, null, NumberFormat.getInstance()}; 107 * MessageFormat pattform = new MessageFormat("There {0} on {1}"); 108 * pattform.setFormats(testFormats); 109 * Object[] testArgs = {null, "ADisk", null}; 110 * for (int i = 0; i < 4; ++i) { 111 * testArgs[0] = new Integer(i); 112 * testArgs[2] = testArgs[0]; 113 * System.out.println(pattform.format(testArgs)); 114 * } 115 * }</pre> 116 * </blockquote> 117 * <p> 118 * Specifying a pattern for ChoiceFormat objects is fairly straightforward. 119 * For example: 120 * <blockquote> 121 * <pre>{@code 122 * ChoiceFormat fmt = new ChoiceFormat( 123 * "-1#is negative| 0#is zero or fraction | 1#is one |1.0<is 1+ |2#is two |2<is more than 2."); 124 * System.out.println("Formatter Pattern : " + fmt.toPattern()); 125 * 126 * System.out.println("Format with -INF : " + fmt.format(Double.NEGATIVE_INFINITY)); 127 * System.out.println("Format with -1.0 : " + fmt.format(-1.0)); 128 * System.out.println("Format with 0 : " + fmt.format(0)); 129 * System.out.println("Format with 0.9 : " + fmt.format(0.9)); 130 * System.out.println("Format with 1.0 : " + fmt.format(1)); 131 * System.out.println("Format with 1.5 : " + fmt.format(1.5)); 132 * System.out.println("Format with 2 : " + fmt.format(2)); 133 * System.out.println("Format with 2.1 : " + fmt.format(2.1)); 134 * System.out.println("Format with NaN : " + fmt.format(Double.NaN)); 135 * System.out.println("Format with +INF : " + fmt.format(Double.POSITIVE_INFINITY)); 136 * }</pre> 137 * </blockquote> 138 * And the output result would be like the following: 139 * <blockquote> 140 * <pre>{@code 141 * Format with -INF : is negative 142 * Format with -1.0 : is negative 143 * Format with 0 : is zero or fraction 144 * Format with 0.9 : is zero or fraction 145 * Format with 1.0 : is one 146 * Format with 1.5 : is 1+ 147 * Format with 2 : is two 148 * Format with 2.1 : is more than 2. 149 * Format with NaN : is negative 150 * Format with +INF : is more than 2. 151 * }</pre> 152 * </blockquote> 153 * 154 * <h2><a id="synchronization">Synchronization</a></h2> 155 * 156 * <p> 157 * Choice formats are not synchronized. 158 * It is recommended to create separate format instances for each thread. 159 * If multiple threads access a format concurrently, it must be synchronized 160 * externally. 161 * 162 * 163 * @see DecimalFormat 164 * @see MessageFormat 165 * @author Mark Davis 166 * @since 1.1 167 */ 168 public class ChoiceFormat extends NumberFormat { 169 170 // Proclaim serial compatibility with 1.1 FCS 171 private static final long serialVersionUID = 1795184449645032964L; 172 173 /** 174 * Sets the pattern. 175 * @param newPattern See the class description. 176 * @exception NullPointerException if {@code newPattern} 177 * is {@code null} 178 */ 179 public void applyPattern(String newPattern) { 180 StringBuffer[] segments = new StringBuffer[2]; 181 for (int i = 0; i < segments.length; ++i) { 182 segments[i] = new StringBuffer(); 183 } 184 double[] newChoiceLimits = new double[30]; 185 String[] newChoiceFormats = new String[30]; 186 int count = 0; 187 int part = 0; 188 double startValue = 0; 189 double oldStartValue = Double.NaN; 190 boolean inQuote = false; 191 for (int i = 0; i < newPattern.length(); ++i) { 192 char ch = newPattern.charAt(i); 193 if (ch=='\'') { 194 // Check for "''" indicating a literal quote 195 if ((i+1)<newPattern.length() && newPattern.charAt(i+1)==ch) { 196 segments[part].append(ch); 197 ++i; 198 } else { 199 inQuote = !inQuote; 200 } 201 } else if (inQuote) { 202 segments[part].append(ch); 203 } else if (ch == '<' || ch == '#' || ch == '\u2264') { 204 if (segments[0].length() == 0) { 205 throw new IllegalArgumentException("Each interval must" 206 + " contain a number before a format"); 207 } 208 209 String tempBuffer = segments[0].toString(); 210 if (tempBuffer.equals("\u221E")) { 211 startValue = Double.POSITIVE_INFINITY; 212 } else if (tempBuffer.equals("-\u221E")) { 213 startValue = Double.NEGATIVE_INFINITY; 214 } else { 215 startValue = Double.parseDouble(tempBuffer); 216 } 217 218 if (ch == '<' && startValue != Double.POSITIVE_INFINITY && 219 startValue != Double.NEGATIVE_INFINITY) { 220 startValue = nextDouble(startValue); 221 } 222 if (startValue <= oldStartValue) { 223 throw new IllegalArgumentException("Incorrect order of" 224 + " intervals, must be in ascending order"); 225 } 226 segments[0].setLength(0); 227 part = 1; 228 } else if (ch == '|') { 229 if (count == newChoiceLimits.length) { 230 newChoiceLimits = doubleArraySize(newChoiceLimits); 231 newChoiceFormats = doubleArraySize(newChoiceFormats); 232 } 233 newChoiceLimits[count] = startValue; 234 newChoiceFormats[count] = segments[1].toString(); 235 ++count; 236 oldStartValue = startValue; 237 segments[1].setLength(0); 238 part = 0; 239 } else { 240 segments[part].append(ch); 241 } 242 } 243 // clean up last one 244 if (part == 1) { 245 if (count == newChoiceLimits.length) { 246 newChoiceLimits = doubleArraySize(newChoiceLimits); 247 newChoiceFormats = doubleArraySize(newChoiceFormats); 248 } 249 newChoiceLimits[count] = startValue; 250 newChoiceFormats[count] = segments[1].toString(); 251 ++count; 252 } 253 choiceLimits = new double[count]; 254 System.arraycopy(newChoiceLimits, 0, choiceLimits, 0, count); 255 choiceFormats = new String[count]; 256 System.arraycopy(newChoiceFormats, 0, choiceFormats, 0, count); 257 } 258 259 /** 260 * Gets the pattern. 261 * 262 * @return the pattern string 263 */ 264 public String toPattern() { 265 StringBuilder result = new StringBuilder(); 266 for (int i = 0; i < choiceLimits.length; ++i) { 267 if (i != 0) { 268 result.append('|'); 269 } 270 // choose based upon which has less precision 271 // approximate that by choosing the closest one to an integer. 272 // could do better, but it's not worth it. 273 double less = previousDouble(choiceLimits[i]); 274 double tryLessOrEqual = Math.abs(Math.IEEEremainder(choiceLimits[i], 1.0d)); 275 double tryLess = Math.abs(Math.IEEEremainder(less, 1.0d)); 276 277 if (tryLessOrEqual < tryLess) { 278 result.append(choiceLimits[i]); 279 result.append('#'); 280 } else { 281 if (choiceLimits[i] == Double.POSITIVE_INFINITY) { 282 result.append("\u221E"); 283 } else if (choiceLimits[i] == Double.NEGATIVE_INFINITY) { 284 result.append("-\u221E"); 285 } else { 286 result.append(less); 287 } 288 result.append('<'); 289 } 290 // Append choiceFormats[i], using quotes if there are special characters. 291 // Single quotes themselves must be escaped in either case. 292 String text = choiceFormats[i]; 293 boolean needQuote = text.indexOf('<') >= 0 294 || text.indexOf('#') >= 0 295 || text.indexOf('\u2264') >= 0 296 || text.indexOf('|') >= 0; 297 if (needQuote) result.append('\''); 298 if (text.indexOf('\'') < 0) result.append(text); 299 else { 300 for (int j=0; j<text.length(); ++j) { 301 char c = text.charAt(j); 302 result.append(c); 303 if (c == '\'') result.append(c); 304 } 305 } 306 if (needQuote) result.append('\''); 307 } 308 return result.toString(); 309 } 310 311 /** 312 * Constructs with limits and corresponding formats based on the pattern. 313 * 314 * @param newPattern the new pattern string 315 * @exception NullPointerException if {@code newPattern} is 316 * {@code null} 317 * @see #applyPattern 318 */ 319 public ChoiceFormat(String newPattern) { 320 applyPattern(newPattern); 321 } 322 323 /** 324 * Constructs with the limits and the corresponding formats. 325 * 326 * @param limits limits in ascending order 327 * @param formats corresponding format strings 328 * @exception NullPointerException if {@code limits} or {@code formats} 329 * is {@code null} 330 * @see #setChoices 331 */ 332 public ChoiceFormat(double[] limits, String[] formats) { 333 setChoices(limits, formats); 334 } 335 336 /** 337 * Set the choices to be used in formatting. 338 * @param limits contains the top value that you want 339 * parsed with that format, and should be in ascending sorted order. When 340 * formatting X, the choice will be the i, where 341 * limit[i] ≤ X {@literal <} limit[i+1]. 342 * If the limit array is not in ascending order, the results of formatting 343 * will be incorrect. 344 * @param formats are the formats you want to use for each limit. 345 * They can be either Format objects or Strings. 346 * When formatting with object Y, 347 * if the object is a NumberFormat, then ((NumberFormat) Y).format(X) 348 * is called. Otherwise Y.toString() is called. 349 * @exception NullPointerException if {@code limits} or 350 * {@code formats} is {@code null} 351 */ 352 public void setChoices(double[] limits, String formats[]) { 353 if (limits.length != formats.length) { 354 throw new IllegalArgumentException( 355 "Array and limit arrays must be of the same length."); 356 } 357 choiceLimits = Arrays.copyOf(limits, limits.length); 358 choiceFormats = Arrays.copyOf(formats, formats.length); 359 } 360 361 /** 362 * Get the limits passed in the constructor. 363 * @return the limits. 364 */ 365 public double[] getLimits() { 366 double[] newLimits = Arrays.copyOf(choiceLimits, choiceLimits.length); 367 return newLimits; 368 } 369 370 /** 371 * Get the formats passed in the constructor. 372 * @return the formats. 373 */ 374 public Object[] getFormats() { 375 Object[] newFormats = Arrays.copyOf(choiceFormats, choiceFormats.length); 376 return newFormats; 377 } 378 379 // Overrides 380 381 /** 382 * Specialization of format. This method really calls 383 * <code>format(double, StringBuffer, FieldPosition)</code> 384 * thus the range of longs that are supported is only equal to 385 * the range that can be stored by double. This will never be 386 * a practical limitation. 387 */ 388 public StringBuffer format(long number, StringBuffer toAppendTo, 389 FieldPosition status) { 390 return format((double)number, toAppendTo, status); 391 } 392 393 /** 394 * Returns pattern with formatted double. 395 * @param number number to be formatted and substituted. 396 * @param toAppendTo where text is appended. 397 * @param status ignore no useful status is returned. 398 * @exception NullPointerException if {@code toAppendTo} 399 * is {@code null} 400 */ 401 public StringBuffer format(double number, StringBuffer toAppendTo, 402 FieldPosition status) { 403 // find the number 404 int i; 405 for (i = 0; i < choiceLimits.length; ++i) { 406 if (!(number >= choiceLimits[i])) { 407 // same as number < choiceLimits, except catchs NaN 408 break; 409 } 410 } 411 --i; 412 if (i < 0) i = 0; 413 // return either a formatted number, or a string 414 return toAppendTo.append(choiceFormats[i]); 415 } 416 417 /** 418 * Parses a Number from the input text. 419 * @param text the source text. 420 * @param status an input-output parameter. On input, the 421 * status.index field indicates the first character of the 422 * source text that should be parsed. On exit, if no error 423 * occurred, status.index is set to the first unparsed character 424 * in the source text. On exit, if an error did occur, 425 * status.index is unchanged and status.errorIndex is set to the 426 * first index of the character that caused the parse to fail. 427 * @return A Number representing the value of the number parsed. 428 * @exception NullPointerException if {@code status} is {@code null} 429 * or if {@code text} is {@code null} and the list of 430 * choice strings is not empty. 431 */ 432 public Number parse(String text, ParsePosition status) { 433 // find the best number (defined as the one with the longest parse) 434 int start = status.index; 435 int furthest = start; 436 double bestNumber = Double.NaN; 437 double tempNumber = 0.0; 438 for (int i = 0; i < choiceFormats.length; ++i) { 439 String tempString = choiceFormats[i]; 440 if (text.regionMatches(start, tempString, 0, tempString.length())) { 441 status.index = start + tempString.length(); 442 tempNumber = choiceLimits[i]; 443 if (status.index > furthest) { 444 furthest = status.index; 445 bestNumber = tempNumber; 446 if (furthest == text.length()) break; 447 } 448 } 449 } 450 status.index = furthest; 451 if (status.index == start) { 452 status.errorIndex = furthest; 453 } 454 return Double.valueOf(bestNumber); 455 } 456 457 /** 458 * Finds the least double greater than {@code d}. 459 * If {@code NaN}, returns same value. 460 * <p>Used to make half-open intervals. 461 * 462 * @implNote This is equivalent to calling 463 * {@link Math#nextUp(double) Math.nextUp(d)} 464 * 465 * @param d the reference value 466 * @return the least double value greather than {@code d} 467 * @see #previousDouble 468 */ 469 public static final double nextDouble (double d) { 470 return Math.nextUp(d); 471 } 472 473 /** 474 * Finds the greatest double less than {@code d}. 475 * If {@code NaN}, returns same value. 476 * 477 * @implNote This is equivalent to calling 478 * {@link Math#nextDown(double) Math.nextDown(d)} 479 * 480 * @param d the reference value 481 * @return the greatest double value less than {@code d} 482 * @see #nextDouble 483 */ 484 public static final double previousDouble (double d) { 485 return Math.nextDown(d); 486 } 487 488 /** 489 * Overrides Cloneable 490 */ 491 public Object clone() 492 { 493 ChoiceFormat other = (ChoiceFormat) super.clone(); 494 // for primitives or immutables, shallow clone is enough 495 other.choiceLimits = choiceLimits.clone(); 496 other.choiceFormats = choiceFormats.clone(); 497 return other; 498 } 499 500 /** 501 * Generates a hash code for the message format object. 502 */ 503 public int hashCode() { 504 int result = choiceLimits.length; 505 if (choiceFormats.length > 0) { 506 // enough for reasonable distribution 507 result ^= choiceFormats[choiceFormats.length-1].hashCode(); 508 } 509 return result; 510 } 511 512 /** 513 * Equality comparison between two 514 */ 515 public boolean equals(Object obj) { 516 if (obj == null) return false; 517 if (this == obj) // quick check 518 return true; 519 if (getClass() != obj.getClass()) 520 return false; 521 ChoiceFormat other = (ChoiceFormat) obj; 522 return (Arrays.equals(choiceLimits, other.choiceLimits) 523 && Arrays.equals(choiceFormats, other.choiceFormats)); 524 } 525 526 /** 527 * After reading an object from the input stream, do a simple verification 528 * to maintain class invariants. 529 * @throws InvalidObjectException if the objects read from the stream is invalid. 530 */ 531 private void readObject(ObjectInputStream in) throws IOException, ClassNotFoundException { 532 in.defaultReadObject(); 533 if (choiceLimits.length != choiceFormats.length) { 534 throw new InvalidObjectException( 535 "limits and format arrays of different length."); 536 } 537 } 538 539 // ===============privates=========================== 540 541 /** 542 * A list of lower bounds for the choices. The formatter will return 543 * <code>choiceFormats[i]</code> if the number being formatted is greater than or equal to 544 * <code>choiceLimits[i]</code> and less than <code>choiceLimits[i+1]</code>. 545 * @serial 546 */ 547 private double[] choiceLimits; 548 549 /** 550 * A list of choice strings. The formatter will return 551 * <code>choiceFormats[i]</code> if the number being formatted is greater than or equal to 552 * <code>choiceLimits[i]</code> and less than <code>choiceLimits[i+1]</code>. 553 * @serial 554 */ 555 private String[] choiceFormats; 556 557 /** 558 * Finds the least double greater than {@code d} (if {@code positive} is 559 * {@code true}), or the greatest double less than {@code d} (if 560 * {@code positive} is {@code false}). 561 * If {@code NaN}, returns same value. 562 * 563 * @implNote This is equivalent to calling 564 * {@code positive ? Math.nextUp(d) : Math.nextDown(d)} 565 * 566 * @param d the reference value 567 * @param positive {@code true} if the least double is desired; 568 * {@code false} otherwise 569 * @return the least or greater double value 570 */ 571 public static double nextDouble (double d, boolean positive) { 572 return positive ? Math.nextUp(d) : Math.nextDown(d); 573 } 574 575 private static double[] doubleArraySize(double[] array) { 576 int oldSize = array.length; 577 double[] newArray = new double[oldSize * 2]; 578 System.arraycopy(array, 0, newArray, 0, oldSize); 579 return newArray; 580 } 581 582 private String[] doubleArraySize(String[] array) { 583 int oldSize = array.length; 584 String[] newArray = new String[oldSize * 2]; 585 System.arraycopy(array, 0, newArray, 0, oldSize); 586 return newArray; 587 } 588 589 }