1 /*
   2  * Copyright (c) 1996, 2018, 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
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   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
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  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
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  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] &le; X &lt; 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  * <h3><a id="synchronization">Synchronization</a></h3>
 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] &le; 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 }