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
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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).
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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] ≤ 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 @java.io.Serial
172 private static final long serialVersionUID = 1795184449645032964L;
173
174 /**
175 * Sets the pattern.
176 * @param newPattern See the class description.
177 * @throws NullPointerException if {@code newPattern}
178 * is {@code null}
179 */
180 public void applyPattern(String newPattern) {
181 StringBuffer[] segments = new StringBuffer[2];
182 for (int i = 0; i < segments.length; ++i) {
183 segments[i] = new StringBuffer();
184 }
185 double[] newChoiceLimits = new double[30];
186 String[] newChoiceFormats = new String[30];
187 int count = 0;
188 int part = 0;
189 double startValue = 0;
190 double oldStartValue = Double.NaN;
191 boolean inQuote = false;
192 for (int i = 0; i < newPattern.length(); ++i) {
193 char ch = newPattern.charAt(i);
194 if (ch=='\'') {
195 // Check for "''" indicating a literal quote
196 if ((i+1)<newPattern.length() && newPattern.charAt(i+1)==ch) {
197 segments[part].append(ch);
198 ++i;
199 } else {
200 inQuote = !inQuote;
201 }
202 } else if (inQuote) {
203 segments[part].append(ch);
204 } else if (ch == '<' || ch == '#' || ch == '\u2264') {
205 if (segments[0].length() == 0) {
206 throw new IllegalArgumentException("Each interval must"
207 + " contain a number before a format");
208 }
209
210 String tempBuffer = segments[0].toString();
211 if (tempBuffer.equals("\u221E")) {
212 startValue = Double.POSITIVE_INFINITY;
213 } else if (tempBuffer.equals("-\u221E")) {
214 startValue = Double.NEGATIVE_INFINITY;
215 } else {
216 startValue = Double.parseDouble(tempBuffer);
217 }
218
219 if (ch == '<' && startValue != Double.POSITIVE_INFINITY &&
220 startValue != Double.NEGATIVE_INFINITY) {
221 startValue = nextDouble(startValue);
222 }
223 if (startValue <= oldStartValue) {
224 throw new IllegalArgumentException("Incorrect order of"
225 + " intervals, must be in ascending order");
226 }
227 segments[0].setLength(0);
228 part = 1;
229 } else if (ch == '|') {
230 if (count == newChoiceLimits.length) {
231 newChoiceLimits = doubleArraySize(newChoiceLimits);
232 newChoiceFormats = doubleArraySize(newChoiceFormats);
233 }
234 newChoiceLimits[count] = startValue;
235 newChoiceFormats[count] = segments[1].toString();
236 ++count;
237 oldStartValue = startValue;
238 segments[1].setLength(0);
239 part = 0;
240 } else {
241 segments[part].append(ch);
242 }
243 }
244 // clean up last one
245 if (part == 1) {
246 if (count == newChoiceLimits.length) {
247 newChoiceLimits = doubleArraySize(newChoiceLimits);
248 newChoiceFormats = doubleArraySize(newChoiceFormats);
249 }
250 newChoiceLimits[count] = startValue;
251 newChoiceFormats[count] = segments[1].toString();
252 ++count;
253 }
254 choiceLimits = new double[count];
255 System.arraycopy(newChoiceLimits, 0, choiceLimits, 0, count);
256 choiceFormats = new String[count];
257 System.arraycopy(newChoiceFormats, 0, choiceFormats, 0, count);
258 }
259
260 /**
261 * Gets the pattern.
262 *
263 * @return the pattern string
264 */
265 public String toPattern() {
266 StringBuilder result = new StringBuilder();
267 for (int i = 0; i < choiceLimits.length; ++i) {
268 if (i != 0) {
269 result.append('|');
270 }
271 // choose based upon which has less precision
272 // approximate that by choosing the closest one to an integer.
273 // could do better, but it's not worth it.
274 double less = previousDouble(choiceLimits[i]);
275 double tryLessOrEqual = Math.abs(Math.IEEEremainder(choiceLimits[i], 1.0d));
276 double tryLess = Math.abs(Math.IEEEremainder(less, 1.0d));
277
278 if (tryLessOrEqual < tryLess) {
279 result.append(choiceLimits[i]);
280 result.append('#');
281 } else {
282 if (choiceLimits[i] == Double.POSITIVE_INFINITY) {
283 result.append("\u221E");
284 } else if (choiceLimits[i] == Double.NEGATIVE_INFINITY) {
285 result.append("-\u221E");
286 } else {
287 result.append(less);
288 }
289 result.append('<');
290 }
291 // Append choiceFormats[i], using quotes if there are special characters.
292 // Single quotes themselves must be escaped in either case.
293 String text = choiceFormats[i];
294 boolean needQuote = text.indexOf('<') >= 0
295 || text.indexOf('#') >= 0
296 || text.indexOf('\u2264') >= 0
297 || text.indexOf('|') >= 0;
298 if (needQuote) result.append('\'');
299 if (text.indexOf('\'') < 0) result.append(text);
300 else {
301 for (int j=0; j<text.length(); ++j) {
302 char c = text.charAt(j);
303 result.append(c);
304 if (c == '\'') result.append(c);
305 }
306 }
307 if (needQuote) result.append('\'');
308 }
309 return result.toString();
310 }
311
312 /**
313 * Constructs with limits and corresponding formats based on the pattern.
314 *
315 * @param newPattern the new pattern string
316 * @throws NullPointerException if {@code newPattern} is
317 * {@code null}
318 * @see #applyPattern
319 */
320 public ChoiceFormat(String newPattern) {
321 applyPattern(newPattern);
322 }
323
324 /**
325 * Constructs with the limits and the corresponding formats.
326 *
327 * @param limits limits in ascending order
328 * @param formats corresponding format strings
329 * @throws NullPointerException if {@code limits} or {@code formats}
330 * is {@code null}
331 * @see #setChoices
332 */
333 public ChoiceFormat(double[] limits, String[] formats) {
334 setChoices(limits, formats);
335 }
336
337 /**
338 * Set the choices to be used in formatting.
339 * @param limits contains the top value that you want
340 * parsed with that format, and should be in ascending sorted order. When
341 * formatting X, the choice will be the i, where
342 * limit[i] ≤ X {@literal <} limit[i+1].
343 * If the limit array is not in ascending order, the results of formatting
344 * will be incorrect.
345 * @param formats are the formats you want to use for each limit.
346 * They can be either Format objects or Strings.
347 * When formatting with object Y,
348 * if the object is a NumberFormat, then ((NumberFormat) Y).format(X)
349 * is called. Otherwise Y.toString() is called.
350 * @throws NullPointerException if {@code limits} or
351 * {@code formats} is {@code null}
352 */
353 public void setChoices(double[] limits, String formats[]) {
354 if (limits.length != formats.length) {
355 throw new IllegalArgumentException(
356 "Array and limit arrays must be of the same length.");
357 }
358 choiceLimits = Arrays.copyOf(limits, limits.length);
359 choiceFormats = Arrays.copyOf(formats, formats.length);
360 }
361
362 /**
363 * Get the limits passed in the constructor.
364 * @return the limits.
365 */
366 public double[] getLimits() {
367 double[] newLimits = Arrays.copyOf(choiceLimits, choiceLimits.length);
368 return newLimits;
369 }
370
371 /**
372 * Get the formats passed in the constructor.
373 * @return the formats.
374 */
375 public Object[] getFormats() {
376 Object[] newFormats = Arrays.copyOf(choiceFormats, choiceFormats.length);
377 return newFormats;
378 }
379
380 // Overrides
381
382 /**
383 * Specialization of format. This method really calls
384 * <code>format(double, StringBuffer, FieldPosition)</code>
385 * thus the range of longs that are supported is only equal to
386 * the range that can be stored by double. This will never be
387 * a practical limitation.
388 */
389 public StringBuffer format(long number, StringBuffer toAppendTo,
390 FieldPosition status) {
391 return format((double)number, toAppendTo, status);
392 }
393
394 /**
395 * Returns pattern with formatted double.
396 * @param number number to be formatted and substituted.
397 * @param toAppendTo where text is appended.
398 * @param status ignore no useful status is returned.
399 * @throws NullPointerException if {@code toAppendTo}
400 * is {@code null}
401 */
402 public StringBuffer format(double number, StringBuffer toAppendTo,
403 FieldPosition status) {
404 // find the number
405 int i;
406 for (i = 0; i < choiceLimits.length; ++i) {
407 if (!(number >= choiceLimits[i])) {
408 // same as number < choiceLimits, except catchs NaN
409 break;
410 }
411 }
412 --i;
413 if (i < 0) i = 0;
414 // return either a formatted number, or a string
415 return toAppendTo.append(choiceFormats[i]);
416 }
417
418 /**
419 * Parses a Number from the input text.
420 * @param text the source text.
421 * @param status an input-output parameter. On input, the
422 * status.index field indicates the first character of the
423 * source text that should be parsed. On exit, if no error
424 * occurred, status.index is set to the first unparsed character
425 * in the source text. On exit, if an error did occur,
426 * status.index is unchanged and status.errorIndex is set to the
427 * first index of the character that caused the parse to fail.
428 * @return A Number representing the value of the number parsed.
429 * @throws NullPointerException if {@code status} is {@code null}
430 * or if {@code text} is {@code null} and the list of
431 * choice strings is not empty.
432 */
433 public Number parse(String text, ParsePosition status) {
434 // find the best number (defined as the one with the longest parse)
435 int start = status.index;
436 int furthest = start;
437 double bestNumber = Double.NaN;
438 double tempNumber = 0.0;
439 for (int i = 0; i < choiceFormats.length; ++i) {
440 String tempString = choiceFormats[i];
441 if (text.regionMatches(start, tempString, 0, tempString.length())) {
442 status.index = start + tempString.length();
443 tempNumber = choiceLimits[i];
444 if (status.index > furthest) {
445 furthest = status.index;
446 bestNumber = tempNumber;
447 if (furthest == text.length()) break;
448 }
449 }
450 }
451 status.index = furthest;
452 if (status.index == start) {
453 status.errorIndex = furthest;
454 }
455 return Double.valueOf(bestNumber);
456 }
457
458 /**
459 * Finds the least double greater than {@code d}.
460 * If {@code NaN}, returns same value.
461 * <p>Used to make half-open intervals.
462 *
463 * @implNote This is equivalent to calling
464 * {@link Math#nextUp(double) Math.nextUp(d)}
465 *
466 * @param d the reference value
467 * @return the least double value greather than {@code d}
468 * @see #previousDouble
469 */
470 public static final double nextDouble (double d) {
471 return Math.nextUp(d);
472 }
473
474 /**
475 * Finds the greatest double less than {@code d}.
476 * If {@code NaN}, returns same value.
477 *
478 * @implNote This is equivalent to calling
479 * {@link Math#nextDown(double) Math.nextDown(d)}
480 *
481 * @param d the reference value
482 * @return the greatest double value less than {@code d}
483 * @see #nextDouble
484 */
485 public static final double previousDouble (double d) {
486 return Math.nextDown(d);
487 }
488
489 /**
490 * Overrides Cloneable
491 */
492 public Object clone()
493 {
494 ChoiceFormat other = (ChoiceFormat) super.clone();
495 // for primitives or immutables, shallow clone is enough
496 other.choiceLimits = choiceLimits.clone();
497 other.choiceFormats = choiceFormats.clone();
498 return other;
499 }
500
501 /**
502 * Generates a hash code for the message format object.
503 */
504 public int hashCode() {
505 int result = choiceLimits.length;
506 if (choiceFormats.length > 0) {
507 // enough for reasonable distribution
508 result ^= choiceFormats[choiceFormats.length-1].hashCode();
509 }
510 return result;
511 }
512
513 /**
514 * Equality comparison between two
515 */
516 public boolean equals(Object obj) {
517 if (obj == null) return false;
518 if (this == obj) // quick check
519 return true;
520 if (getClass() != obj.getClass())
521 return false;
522 ChoiceFormat other = (ChoiceFormat) obj;
523 return (Arrays.equals(choiceLimits, other.choiceLimits)
524 && Arrays.equals(choiceFormats, other.choiceFormats));
525 }
526
527 /**
528 * After reading an object from the input stream, do a simple verification
529 * to maintain class invariants.
530 * @throws InvalidObjectException if the objects read from the stream is invalid.
531 */
532 @java.io.Serial
533 private void readObject(ObjectInputStream in) throws IOException, ClassNotFoundException {
534 in.defaultReadObject();
535 if (choiceLimits.length != choiceFormats.length) {
536 throw new InvalidObjectException(
537 "limits and format arrays of different length.");
538 }
539 }
540
541 // ===============privates===========================
542
543 /**
544 * A list of lower bounds for the choices. The formatter will return
545 * <code>choiceFormats[i]</code> if the number being formatted is greater than or equal to
546 * <code>choiceLimits[i]</code> and less than <code>choiceLimits[i+1]</code>.
547 * @serial
548 */
549 private double[] choiceLimits;
550
551 /**
552 * A list of choice strings. The formatter will return
553 * <code>choiceFormats[i]</code> if the number being formatted is greater than or equal to
554 * <code>choiceLimits[i]</code> and less than <code>choiceLimits[i+1]</code>.
555 * @serial
556 */
557 private String[] choiceFormats;
558
559 /**
560 * Finds the least double greater than {@code d} (if {@code positive} is
561 * {@code true}), or the greatest double less than {@code d} (if
562 * {@code positive} is {@code false}).
563 * If {@code NaN}, returns same value.
564 *
565 * @implNote This is equivalent to calling
566 * {@code positive ? Math.nextUp(d) : Math.nextDown(d)}
567 *
568 * @param d the reference value
569 * @param positive {@code true} if the least double is desired;
570 * {@code false} otherwise
571 * @return the least or greater double value
572 */
573 public static double nextDouble (double d, boolean positive) {
574 return positive ? Math.nextUp(d) : Math.nextDown(d);
575 }
576
577 private static double[] doubleArraySize(double[] array) {
578 int oldSize = array.length;
579 double[] newArray = new double[oldSize * 2];
580 System.arraycopy(array, 0, newArray, 0, oldSize);
581 return newArray;
582 }
583
584 private String[] doubleArraySize(String[] array) {
585 int oldSize = array.length;
586 String[] newArray = new String[oldSize * 2];
587 System.arraycopy(array, 0, newArray, 0, oldSize);
588 return newArray;
589 }
590
591 }