1 /*
2 * Copyright (c) 1996, 2017, 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
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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 * <h3><a name="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 */
167 public class ChoiceFormat extends NumberFormat {
168
169 // Proclaim serial compatibility with 1.1 FCS
170 private static final long serialVersionUID = 1795184449645032964L;
171
172 /**
173 * Sets the pattern.
174 * @param newPattern See the class description.
175 * @exception NullPointerException if {@code newPattern}
176 * is {@code null}
177 */
178 public void applyPattern(String newPattern) {
179 StringBuffer[] segments = new StringBuffer[2];
180 for (int i = 0; i < segments.length; ++i) {
181 segments[i] = new StringBuffer();
182 }
183 double[] newChoiceLimits = new double[30];
184 String[] newChoiceFormats = new String[30];
185 int count = 0;
186 int part = 0;
187 double startValue = 0;
188 double oldStartValue = Double.NaN;
189 boolean inQuote = false;
190 for (int i = 0; i < newPattern.length(); ++i) {
191 char ch = newPattern.charAt(i);
192 if (ch=='\'') {
193 // Check for "''" indicating a literal quote
194 if ((i+1)<newPattern.length() && newPattern.charAt(i+1)==ch) {
195 segments[part].append(ch);
196 ++i;
197 } else {
198 inQuote = !inQuote;
199 }
200 } else if (inQuote) {
201 segments[part].append(ch);
202 } else if (ch == '<' || ch == '#' || ch == '\u2264') {
203 if (segments[0].length() == 0) {
204 throw new IllegalArgumentException();
205 }
206 try {
207 String tempBuffer = segments[0].toString();
208 if (tempBuffer.equals("\u221E")) {
209 startValue = Double.POSITIVE_INFINITY;
210 } else if (tempBuffer.equals("-\u221E")) {
211 startValue = Double.NEGATIVE_INFINITY;
212 } else {
213 startValue = Double.valueOf(segments[0].toString()).doubleValue();
214 }
215 } catch (Exception e) {
216 throw new IllegalArgumentException();
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();
224 }
225 segments[0].setLength(0);
226 part = 1;
227 } else if (ch == '|') {
228 if (count == newChoiceLimits.length) {
229 newChoiceLimits = doubleArraySize(newChoiceLimits);
230 newChoiceFormats = doubleArraySize(newChoiceFormats);
231 }
232 newChoiceLimits[count] = startValue;
233 newChoiceFormats[count] = segments[1].toString();
234 ++count;
235 oldStartValue = startValue;
236 segments[1].setLength(0);
237 part = 0;
238 } else {
239 segments[part].append(ch);
240 }
241 }
242 // clean up last one
243 if (part == 1) {
244 if (count == newChoiceLimits.length) {
245 newChoiceLimits = doubleArraySize(newChoiceLimits);
246 newChoiceFormats = doubleArraySize(newChoiceFormats);
247 }
248 newChoiceLimits[count] = startValue;
249 newChoiceFormats[count] = segments[1].toString();
250 ++count;
251 }
252 choiceLimits = new double[count];
253 System.arraycopy(newChoiceLimits, 0, choiceLimits, 0, count);
254 choiceFormats = new String[count];
255 System.arraycopy(newChoiceFormats, 0, choiceFormats, 0, count);
256 }
257
258 /**
259 * Gets the pattern.
260 *
261 * @return the pattern string
262 */
263 public String toPattern() {
264 StringBuilder result = new StringBuilder();
265 for (int i = 0; i < choiceLimits.length; ++i) {
266 if (i != 0) {
267 result.append('|');
268 }
269 // choose based upon which has less precision
270 // approximate that by choosing the closest one to an integer.
271 // could do better, but it's not worth it.
272 double less = previousDouble(choiceLimits[i]);
273 double tryLessOrEqual = Math.abs(Math.IEEEremainder(choiceLimits[i], 1.0d));
274 double tryLess = Math.abs(Math.IEEEremainder(less, 1.0d));
275
276 if (tryLessOrEqual < tryLess) {
277 result.append(choiceLimits[i]);
278 result.append('#');
279 } else {
280 if (choiceLimits[i] == Double.POSITIVE_INFINITY) {
281 result.append("\u221E");
282 } else if (choiceLimits[i] == Double.NEGATIVE_INFINITY) {
283 result.append("-\u221E");
284 } else {
285 result.append(less);
286 }
287 result.append('<');
288 }
289 // Append choiceFormats[i], using quotes if there are special characters.
290 // Single quotes themselves must be escaped in either case.
291 String text = choiceFormats[i];
292 boolean needQuote = text.indexOf('<') >= 0
293 || text.indexOf('#') >= 0
294 || text.indexOf('\u2264') >= 0
295 || text.indexOf('|') >= 0;
296 if (needQuote) result.append('\'');
297 if (text.indexOf('\'') < 0) result.append(text);
298 else {
299 for (int j=0; j<text.length(); ++j) {
300 char c = text.charAt(j);
301 result.append(c);
302 if (c == '\'') result.append(c);
303 }
304 }
305 if (needQuote) result.append('\'');
306 }
307 return result.toString();
308 }
309
310 /**
311 * Constructs with limits and corresponding formats based on the pattern.
312 *
313 * @param newPattern the new pattern string
314 * @exception NullPointerExcpetion if {@code newPattern} is
315 * {@code null}
316 * @see #applyPattern
317 */
318 public ChoiceFormat(String newPattern) {
319 applyPattern(newPattern);
320 }
321
322 /**
323 * Constructs with the limits and the corresponding formats.
324 *
325 * @param limits limits in ascending order
326 * @param formats corresponding format strings
327 * @exception NullPointerException if {@code limits} or {@code formats}
328 * is {@code null}
329 * @see #setChoices
330 */
331 public ChoiceFormat(double[] limits, String[] formats) {
332 setChoices(limits, formats);
333 }
334
335 /**
336 * Set the choices to be used in formatting.
337 * @param limits contains the top value that you want
338 * parsed with that format, and should be in ascending sorted order. When
339 * formatting X, the choice will be the i, where
340 * limit[i] ≤ X {@literal <} limit[i+1].
341 * If the limit array is not in ascending order, the results of formatting
342 * will be incorrect.
343 * @param formats are the formats you want to use for each limit.
344 * They can be either Format objects or Strings.
345 * When formatting with object Y,
346 * if the object is a NumberFormat, then ((NumberFormat) Y).format(X)
347 * is called. Otherwise Y.toString() is called.
348 * @exception NullPointerException if {@code limits} or
349 * {@code formats} is {@code null}
350 */
351 public void setChoices(double[] limits, String formats[]) {
352 if (limits.length != formats.length) {
353 throw new IllegalArgumentException(
354 "Array and limit arrays must be of the same length.");
355 }
356 choiceLimits = Arrays.copyOf(limits, limits.length);
357 choiceFormats = Arrays.copyOf(formats, formats.length);
358 }
359
360 /**
361 * Get the limits passed in the constructor.
362 * @return the limits.
363 */
364 public double[] getLimits() {
365 double[] newLimits = Arrays.copyOf(choiceLimits, choiceLimits.length);
366 return newLimits;
367 }
368
369 /**
370 * Get the formats passed in the constructor.
371 * @return the formats.
372 */
373 public Object[] getFormats() {
374 Object[] newFormats = Arrays.copyOf(choiceFormats, choiceFormats.length);
375 return newFormats;
376 }
377
378 // Overrides
379
380 /**
381 * Specialization of format. This method really calls
382 * <code>format(double, StringBuffer, FieldPosition)</code>
383 * thus the range of longs that are supported is only equal to
384 * the range that can be stored by double. This will never be
385 * a practical limitation.
386 */
387 public StringBuffer format(long number, StringBuffer toAppendTo,
388 FieldPosition status) {
389 return format((double)number, toAppendTo, status);
390 }
391
392 /**
393 * Returns pattern with formatted double.
394 * @param number number to be formatted and substituted.
395 * @param toAppendTo where text is appended.
396 * @param status ignore no useful status is returned.
397 * @exception NullPointerException if {@code toAppendTo}
398 * is {@code null}
399 */
400 public StringBuffer format(double number, StringBuffer toAppendTo,
401 FieldPosition status) {
402 // find the number
403 int i;
404 for (i = 0; i < choiceLimits.length; ++i) {
405 if (!(number >= choiceLimits[i])) {
406 // same as number < choiceLimits, except catchs NaN
407 break;
408 }
409 }
410 --i;
411 if (i < 0) i = 0;
412 // return either a formatted number, or a string
413 return toAppendTo.append(choiceFormats[i]);
414 }
415
416 /**
417 * Parses a Number from the input text.
418 * @param text the source text.
419 * @param status an input-output parameter. On input, the
420 * status.index field indicates the first character of the
421 * source text that should be parsed. On exit, if no error
422 * occurred, status.index is set to the first unparsed character
423 * in the source text. On exit, if an error did occur,
424 * status.index is unchanged and status.errorIndex is set to the
425 * first index of the character that caused the parse to fail.
426 * @return A Number representing the value of the number parsed.
427 * @exception NullPointerException if {@code status} is {@code null}
428 * or if {@code text} is {@code null} and the list of
429 * choice strings is not empty.
430 */
431 public Number parse(String text, ParsePosition status) {
432 // find the best number (defined as the one with the longest parse)
433 int start = status.index;
434 int furthest = start;
435 double bestNumber = Double.NaN;
436 double tempNumber = 0.0;
437 for (int i = 0; i < choiceFormats.length; ++i) {
438 String tempString = choiceFormats[i];
439 if (text.regionMatches(start, tempString, 0, tempString.length())) {
440 status.index = start + tempString.length();
441 tempNumber = choiceLimits[i];
442 if (status.index > furthest) {
443 furthest = status.index;
444 bestNumber = tempNumber;
445 if (furthest == text.length()) break;
446 }
447 }
448 }
449 status.index = furthest;
450 if (status.index == start) {
451 status.errorIndex = furthest;
452 }
453 return Double.valueOf(bestNumber);
454 }
455
456 /**
457 * Finds the least double greater than {@code d}.
458 * If {@code NaN}, returns same value.
459 * <p>Used to make half-open intervals.
460 *
461 * @param d the reference value
462 * @return the least double value greather than {@code d}
463 * @see #previousDouble
464 */
465 public static final double nextDouble (double d) {
466 return nextDouble(d,true);
467 }
468
469 /**
470 * Finds the greatest double less than {@code d}.
471 * If {@code NaN}, returns same value.
472 *
473 * @param d the reference value
474 * @return the greatest double value less than {@code d}
475 * @see #nextDouble
476 */
477 public static final double previousDouble (double d) {
478 return nextDouble(d,false);
479 }
480
481 /**
482 * Overrides Cloneable
483 */
484 public Object clone()
485 {
486 ChoiceFormat other = (ChoiceFormat) super.clone();
487 // for primitives or immutables, shallow clone is enough
488 other.choiceLimits = choiceLimits.clone();
489 other.choiceFormats = choiceFormats.clone();
490 return other;
491 }
492
493 /**
494 * Generates a hash code for the message format object.
495 */
496 public int hashCode() {
497 int result = choiceLimits.length;
498 if (choiceFormats.length > 0) {
499 // enough for reasonable distribution
500 result ^= choiceFormats[choiceFormats.length-1].hashCode();
501 }
502 return result;
503 }
504
505 /**
506 * Equality comparison between two
507 */
508 public boolean equals(Object obj) {
509 if (obj == null) return false;
510 if (this == obj) // quick check
511 return true;
512 if (getClass() != obj.getClass())
513 return false;
514 ChoiceFormat other = (ChoiceFormat) obj;
515 return (Arrays.equals(choiceLimits, other.choiceLimits)
516 && Arrays.equals(choiceFormats, other.choiceFormats));
517 }
518
519 /**
520 * After reading an object from the input stream, do a simple verification
521 * to maintain class invariants.
522 * @throws InvalidObjectException if the objects read from the stream is invalid.
523 */
524 private void readObject(ObjectInputStream in) throws IOException, ClassNotFoundException {
525 in.defaultReadObject();
526 if (choiceLimits.length != choiceFormats.length) {
527 throw new InvalidObjectException(
528 "limits and format arrays of different length.");
529 }
530 }
531
532 // ===============privates===========================
533
534 /**
535 * A list of lower bounds for the choices. The formatter will return
536 * <code>choiceFormats[i]</code> if the number being formatted is greater than or equal to
537 * <code>choiceLimits[i]</code> and less than <code>choiceLimits[i+1]</code>.
538 * @serial
539 */
540 private double[] choiceLimits;
541
542 /**
543 * A list of choice strings. The formatter will return
544 * <code>choiceFormats[i]</code> if the number being formatted is greater than or equal to
545 * <code>choiceLimits[i]</code> and less than <code>choiceLimits[i+1]</code>.
546 * @serial
547 */
548 private String[] choiceFormats;
549
550 /*
551 static final long SIGN = 0x8000000000000000L;
552 static final long EXPONENT = 0x7FF0000000000000L;
553 static final long SIGNIFICAND = 0x000FFFFFFFFFFFFFL;
554
555 private static double nextDouble (double d, boolean positive) {
556 if (Double.isNaN(d) || Double.isInfinite(d)) {
557 return d;
558 }
559 long bits = Double.doubleToLongBits(d);
560 long significand = bits & SIGNIFICAND;
561 if (bits < 0) {
562 significand |= (SIGN | EXPONENT);
563 }
564 long exponent = bits & EXPONENT;
565 if (positive) {
566 significand += 1;
567 // FIXME fix overflow & underflow
568 } else {
569 significand -= 1;
570 // FIXME fix overflow & underflow
571 }
572 bits = exponent | (significand & ~EXPONENT);
573 return Double.longBitsToDouble(bits);
574 }
575 */
576
577 static final long SIGN = 0x8000000000000000L;
578 static final long EXPONENT = 0x7FF0000000000000L;
579 static final long POSITIVEINFINITY = 0x7FF0000000000000L;
580
581 /**
582 * Finds the least double greater than {@code d} (if {@code positive} is
583 * {@code true}), or the greatest double less than {@code d} (if
584 * {@code positive} is {@code false}).
585 * If {@code NaN}, returns same value.
586 *
587 * Does not affect floating-point flags,
588 * provided these member functions do not:
589 * Double.longBitsToDouble(long)
590 * Double.doubleToLongBits(double)
591 * Double.isNaN(double)
592 *
593 * @param d the reference value
594 * @param positive {@code true} if the least double is desired;
595 * {@code false} otherwise
596 * @return the least or greater double value
597 */
598 public static double nextDouble (double d, boolean positive) {
599
600 /* filter out NaN's */
601 if (Double.isNaN(d)) {
602 return d;
603 }
604
605 /* zero's are also a special case */
606 if (d == 0.0) {
607 double smallestPositiveDouble = Double.longBitsToDouble(1L);
608 if (positive) {
609 return smallestPositiveDouble;
610 } else {
611 return -smallestPositiveDouble;
612 }
613 }
614
615 /* if entering here, d is a nonzero value */
616
617 /* hold all bits in a long for later use */
618 long bits = Double.doubleToLongBits(d);
619
620 /* strip off the sign bit */
621 long magnitude = bits & ~SIGN;
622
623 /* if next double away from zero, increase magnitude */
624 if ((bits > 0) == positive) {
625 if (magnitude != POSITIVEINFINITY) {
626 magnitude += 1;
627 }
628 }
629 /* else decrease magnitude */
630 else {
631 magnitude -= 1;
632 }
633
634 /* restore sign bit and return */
635 long signbit = bits & SIGN;
636 return Double.longBitsToDouble (magnitude | signbit);
637 }
638
639 private static double[] doubleArraySize(double[] array) {
640 int oldSize = array.length;
641 double[] newArray = new double[oldSize * 2];
642 System.arraycopy(array, 0, newArray, 0, oldSize);
643 return newArray;
644 }
645
646 private String[] doubleArraySize(String[] array) {
647 int oldSize = array.length;
648 String[] newArray = new String[oldSize * 2];
649 System.arraycopy(array, 0, newArray, 0, oldSize);
650 return newArray;
651 }
652
653 }